├── LICENSE ├── README.md ├── beaglebone.gemspec ├── lib ├── beaglebone.rb └── beaglebone │ ├── ain.rb │ ├── beaglebone.rb │ ├── gpio.rb │ ├── i2c.rb │ ├── pwm.rb │ ├── shiftregister.rb │ ├── spi.rb │ └── uart.rb └── procedural-examples.md /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | {project} Copyright (C) {year} {fullname} 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Beaglebone Ruby Library 2 | 3 | **Table of Contents** 4 | - [Overview](#overview) 5 | - [Installation](#installation) 6 | - [Installing Ruby](#installing-ruby) 7 | - [Installing Beaglebone Gem](#installing-beaglebone-gem) 8 | - [Updating Beaglebone Gem](#updating-beaglebone-gem) 9 | - [Usage](#usage) 10 | - [Ruby in Cloud9](#ruby-in-cloud9) 11 | - [Pin Information](#pin-information) 12 | - [GPIO Pins](#gpio-pins) 13 | - [Analog Pins](#analog-pins) 14 | - [PWM Pins](#pwm-pins) 15 | - [UART Pins](#uart-pins) 16 | - [I2C Pins](#i2c-pins) 17 | - [SPI Pins](#spi-pins) 18 | - [Source Code Reference](#source-code-reference) 19 | - [Examples (Object Oriented)](#examples-object-oriented) 20 | - [GPIO](#gpio) 21 | - [GPIO Writing](#gpio-writing) 22 | - [GPIO Reading](#gpio-reading) 23 | - [LEDs](#leds) 24 | - [Edge Triggers](#edge-triggers) 25 | - [Edge Triggers in the Background](#edge-triggers-in-the-background) 26 | - [Shift Registers](#shift-registers) 27 | - [Analog Inputs](#analog-inputs) 28 | - [Reading](#reading) 29 | - [Waiting for Change](#waiting-for-change) 30 | - [Waiting for Change in the Background](#waiting-for-change-in-the-background) 31 | - [Waiting for Threshold](#waiting-for-threshold) 32 | - [Waiting for Threshold in the Background](#waiting-for-Threshold-in-the-background) 33 | - [PWM](#pwm) 34 | - [UART](#uart) 35 | - [UART Writing](#uart-writing) 36 | - [UART Reading](#uart-reading) 37 | - [UART Reading and Iterating](#uart-reading-and-iterating) 38 | - [UART Reading and Iterating in the Background](#uart-reading-and-iterating-in-the-background) 39 | - [I2C](#i2c) 40 | - [I2C Writing](#i2c-writing) 41 | - [I2C Reading](#i2c-reading) 42 | - [LSM303DLHC Example](#lsm303dlhc-example) 43 | - [SPI](#spi) 44 | - [SPI Data Transfer](#spi-data-transfer) 45 | - [MCP3008 Example](#mcp3008-example) 46 | - [Examples (Procedural)](#examples-procedural) 47 | - [License](#license) 48 | 49 | ## Overview 50 | The purpose of this library is to provide easy access to all of the IO features of the Beaglebone in a highly flexible programming language (Ruby). This gem includes object oriented methods as well as procedural methods, so those familiar with Bonescript, the Adafruit Python library, or Arduino programming will be familiar with the syntax. This was developed and tested on a Beaglebone Black running the official Debian images. The code will need to be executed as root in order to function properly and utilize all of the features of the Beaglebone. 51 | 52 | ## Installation 53 | ### Installing Ruby 54 | Ruby and Rubygems are required to use this gem. To install, simply run the command below. This will install Ruby 1.9.3 which includes Rubygems. 55 | 56 | ``` 57 | sudo apt-get install ruby 58 | ``` 59 | 60 | ### Installing Beaglebone Gem 61 | Once Ruby is installed installed, install the gem by running the command below. 62 | 63 | ``` 64 | sudo gem install beaglebone 65 | ``` 66 | 67 | ### Updating Beaglebone Gem 68 | Once the gem is installed, you can update to the latest version by running the command below. New versions may contain bug fixes and new features. 69 | 70 | ``` 71 | sudo gem update beaglebone 72 | ``` 73 | 74 | ## Usage 75 | To use this gem, require it in the Ruby script. An example follows 76 | 77 | ```ruby 78 | #!/usr/bin/env ruby 79 | require 'beaglebone' 80 | include Beaglebone 81 | ``` 82 | 83 | ### Ruby in Cloud9 84 | Cloud9 has native Ruby support. Name your files with the extension .rb to run Ruby in Cloud9 85 | 86 | ## Pin Information 87 | The Beaglebone has two headers of IO pins. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers). 88 | 89 | ### GPIO Pins 90 | The beaglebone has a large number of GPIO pins. These pins function at 3.3v. Do not provide more than 3.3v to any GPIO pin or risk damaging the hardware. 91 | 92 | There are built in _capes_ that have priority over the GPIO pins unless disabled. These are for HDMI and the onboard eMMC. It is documented [here](http://beagleboard.org/Support/bone101#headers-black). It is possible to disable these _capes_ if you are not using them. 93 | 94 | ### Analog Pins 95 | The beaglebone has 7 Analog inputs. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers-analog). These pins function at 1.8v. Do not provide more than 1.8v to any Analog pin or risk damaging the hardware. The header has pins available to provide a 1.8v for analog devices as well as a dedicated analog ground. 96 | 97 | ### PWM Pins 98 | The beaglebone has 8 PWM pins. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers-pwm). These pins function at 3.3v. 99 | 100 | Not all 8 pins may be used at the same time. You may use the following pins. 101 | 102 | - P8_13 or P8_19 103 | - P9_14 or P9_16 104 | - P9_21 or P9_22 105 | - P9_28 and P9_42 106 | 107 | ### UART Pins 108 | The beaglebone has 5 UART devices available. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers-serial). These pins function at 3.3v. Do not provide more than 3.3v to any UART pin or risk damaging the hardware. 109 | 110 | UART3 only has a TX pin available. 111 | 112 | UART5 TX and RX pins are unavailable by default, as the HDMI _cape_ claims those pins unless disabled. 113 | 114 | ### I2C Pins 115 | The beaglebone has 2 I2C devices available. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers-i2c). These pins function at 3.3v. Do not provide more than 3.3v to any I2C pin or risk damaging the hardware. 116 | 117 | ### SPI Pins 118 | The beaglebone has 2 SPI devices available. Documentation on these pins is available [here](http://beagleboard.org/Support/bone101#headers-spi). These pins function at 3.3v. Do not provide more than 3.3v to any SPI pin or risk damaging the hardware. 119 | 120 | ## Source Code Reference 121 | A full Source Code reference is available [here](http://rubydoc.info/gems/beaglebone/1.0.5/frames). 122 | 123 | ## Examples (Object Oriented) 124 | These examples will show the various ways to interact with the Beaglebones IO hardware. They will need to be executed as root in order to function correctly. 125 | 126 | ### GPIO 127 | The GPIO pins on the Beaglebone run at **3.3v**. Do not provide more than 3.3v to any GPIO pin or risk damaging the hardware. 128 | 129 | GPIO pins have two modes, input and output. These modes are represented by the symbols **:IN** and **:OUT**. 130 | 131 | GPIO pins have internal pullup and pulldown resistors. These modes are represented by the symbols **:PULLUP**, **:PULLDOWN**, and **:NONE**. 132 | 133 | GPIO pins have an adjustable slew rate. These modes are represented by the symbols **:FAST** and **:SLOW** 134 | 135 | To initialize the pin **P9_11**, pass the symbol for that pin and the mode to the **GPIOPin** constructor. 136 | 137 | ```ruby 138 | # Initialize pin P9_11 in INPUT mode 139 | # This method takes 4 arguments 140 | # pin: The pin to initialize 141 | # mode: The GPIO mode, :IN or :OUT 142 | # pullmode: (optional) The pull mode, :PULLUP, :PULLDOWN, or :NONE 143 | # slewrate: (optional) The slew rate, :FAST or :SLOW 144 | p9_11 = GPIOPin.new(:P9_11, :IN, :PULLUP, :FAST) 145 | 146 | # Initialize pin P9_12 in OUTPUT mode 147 | p9_12 = GPIOPin.new(:P9_12, :OUT) 148 | 149 | # Change pin P9_12 to INPUT mode 150 | p9_12.set_gpio_mode(:IN) 151 | 152 | # Disable pin P9_12 153 | p9_12.disable_gpio_pin 154 | 155 | # Unassign to prevent re-use 156 | p9_12 = nil 157 | ``` 158 | 159 | #### GPIO Writing 160 | To set the state of a GPIO pin, the method **#digital_write** is used. The states that can be set are **:HIGH** to provide 3.3v and **:LOW** to provide ground. 161 | 162 | ```ruby 163 | # Initialize pin P9_12 in OUTPUT mode 164 | p9_12 = GPIOPin.new(:P9_12, :OUT) 165 | 166 | # Provide 3.3v on pin P9_12 167 | p9_12.digital_write(:HIGH) 168 | 169 | # Provide ground on pin P9_12 170 | p9_12.digital_write(:LOW) 171 | ``` 172 | 173 | #### GPIO Reading 174 | To read the current state of a GPIO pin, the method **#digital_read** is used. It will return the symbol **:HIGH** or **:LOW** depending on the state of the pin. 175 | 176 | ```ruby 177 | # Initialize pin P9_11 in INPUT mode 178 | p9_11 = GPIOPin.new(:P9_11, :IN) 179 | 180 | # Get the current state of P9_11 181 | state = p9_11.digital_read => :LOW 182 | ``` 183 | 184 | #### LEDs 185 | The on-board LEDs are addressable via GPIO output. They are available on pins **:USR0** through **:USR3**. 186 | 187 | This example will blink each LED in order 5 times. 188 | 189 | ```ruby 190 | # Create an led object for each LED 191 | led1 = GPIOPin.new(:USR0, :OUT) 192 | led2 = GPIOPin.new(:USR1, :OUT) 193 | led3 = GPIOPin.new(:USR2, :OUT) 194 | led4 = GPIOPin.new(:USR3, :OUT) 195 | 196 | # Run the following block 5 times 197 | 5.times do 198 | # Iterate over each LED 199 | [led1,led2,led3,led4].each do |led| 200 | # Turn on the LED 201 | led.digital_write(:HIGH) 202 | # Delay 0.25 seconds 203 | sleep 0.25 204 | # Turn off the LED 205 | led.digital_write(:LOW) 206 | end 207 | end 208 | ``` 209 | 210 | #### Edge Triggers 211 | The Beaglebone can monitor for changes on a GPIO pin. This is called an edge trigger. Since this is interrupt based on the Beaglebone, waiting for a change does not waste CPU cycles by constantly polling the pin. 212 | 213 | The following trigger types are supported 214 | - Rising: Triggered when the state goes from low to high 215 | - Falling: Triggered when the state goes from high to low 216 | - Both: Triggered at any change in state 217 | - None: Triggering is disabled 218 | 219 | These trigger types are represented by the symbols :RISING, :FALLING, :BOTH, and :NONE 220 | 221 | This example will wait for a rising edge to continue, then output the type of edge trigger that was detected. 222 | 223 | ```ruby 224 | # Initialize pin P9_11 in INPUT mode 225 | p9_11 = GPIOPin.new(:P9_11, :IN) 226 | 227 | # Wait here until a rising edge is detected 228 | edge = p9_11.wait_for_edge(:RISING) => :RISING 229 | 230 | # Output the trigger type detected 231 | puts "Saw a #{edge} edge" 232 | ``` 233 | 234 | #### Edge Triggers in the Background 235 | To avoid blocking while waiting for an edge trigger, the method **#run_on_edge** will run a callback when an edge trigger is detected. This method will spawn a new thread and wait for an edge trigger in the background. Only one of these threads may be active per pin. 236 | 237 | This example will detect edge triggers in the background and output information when triggered. 238 | 239 | ```ruby 240 | # Initialize pin P9_11 in INPUT mode 241 | p9_11 = GPIOPin.new(:P9_11, :IN) 242 | 243 | # Define callback to run when an edge trigger is detected 244 | # This method takes 3 arguments. 245 | # pin: The pin that triggered the event 246 | # edge: The event that triggered it 247 | # count: How many times it has been triggered 248 | callback = lambda { |pin,edge,count| puts "[#{count}] #{pin} #{edge}"} 249 | 250 | # Run the callback every time a change in state is detected 251 | # This method has two additional arguments that are optional. 252 | # Timeout: How long to wait for an event before terminating the thread 253 | # Repeats: How many times to run the event 254 | # By default, it will run forever every time the specified trigger is detected 255 | p9_11.run_on_edge(callback, :BOTH) 256 | 257 | # This code will run immediately after the previous call, as it does not block 258 | sleep 10 259 | 260 | # Stop the background thread waiting for an edge trigger after 10 seconds 261 | p9_11.stop_edge_wait 262 | 263 | # This convenience method will run the callback only on the first detected change 264 | p9_11.run_once_on_edge(callback, :BOTH) 265 | 266 | # Change the trigger detection for the specified pin 267 | p9_11.set_gpio_edge(:RISING) 268 | ``` 269 | 270 | #### Shift Registers 271 | This library will support writing to shift registers using GPIO pins. Create a **ShiftRegister** object by initializing it with the latch pin, clock pin, and data pin. 272 | 273 | This example will trigger 8 pins of a shift register. 274 | 275 | ```ruby 276 | # P9_11 is connected to the latch pin 277 | # P9_12 is connected to the clock pin 278 | # P9_13 is connected to the data pin 279 | 280 | # Initialize shift register 281 | shiftreg = ShiftRegister.new(:P9_11, :P9_12, :P9_13) 282 | 283 | # Write value to shift register 284 | shiftreg.shift_out(0b11111111) 285 | ``` 286 | 287 | 288 | ### Analog Inputs 289 | The Analog pins on the Beaglebone run at **1.8v**. Do not provide more than 1.8v to any analog pin or risk damaging the hardware. The header has pins available to provide a 1.8v for analog devices as well as a dedicated analog ground. Analog pins are only capable of reading input values. 290 | 291 | To initialize the pin **P9_33**, pass the symbol for that pin and the mode to the **AINPin** constructor. 292 | 293 | ```ruby 294 | # Initialize pin P9_33 for Analog Input 295 | p9_33 = AINPin.new(:P9_33) 296 | ``` 297 | 298 | #### Reading 299 | To read the value from an analog pin, the method **#read** is used. This will return a value between 0 and 1799. 300 | 301 | ```ruby 302 | # Initialize pin P9_33 for Analog Input 303 | p9_33 = AINPin.new(:P9_33) 304 | 305 | # Read the input value in millivolts. 306 | mv = p9_33.read => 1799 307 | ``` 308 | 309 | #### Waiting for Change 310 | To wait for the value of an analog pin to change by a specified voltage, the method **#wait_for_change** is used. 311 | 312 | **#wait_for_change** takes the following arguments. 313 | - mv_change: The amount of change in millivolts required before returning 314 | - interval: How often to poll the value of the pin in seconds 315 | - mv_last: (optional) The initial value to use as a point to detect change 316 | 317 | This method returns an array containing the initial voltage, the last polled voltage, and the number of times the pin was polled. 318 | 319 | ```ruby 320 | # Initialize pin P9_33 for Analog Input 321 | p9_33 = AINPin.new(:P9_33) 322 | 323 | # Wait for 100mv of change on pin P9_33. Poll 10 times a second 324 | mv_start, mv_current, count = p9_33.wait_for_change(100, 0.1) 325 | ``` 326 | 327 | #### Waiting for Change in the Background 328 | To avoid blocking while waiting for voltage change, the method **#run_on_change** will run a callback every time the specified change is detected. This method will spawn a new thread and wait for change in the background. The method **#run_once_on_change** is a convenience method to only be triggered once. Only one of these threads may be active per pin. 329 | 330 | This example waits for voltage change in the background and outputs information when change is detected. 331 | 332 | ```ruby 333 | # Initialize pin P9_33 for Analog Input 334 | p9_33 = AINPin.new(:P9_33) 335 | 336 | # Define callback to run when condition is met 337 | # This method takes 4 arguments. 338 | # pin: The pin that triggered the event 339 | # mv_last: The initial voltage used to determine change 340 | # mv: The current voltage on the pin 341 | # count: How many times it has been triggered 342 | callback = lambda { |pin, mv_last, mv, count| puts "[#{count}] #{pin} #{mv_last} -> #{mv}" } 343 | 344 | # Run the callback every time the specified voltage change is detected 345 | # This method has one additional argument that is optional. 346 | # Repeats: How many times to will run the event 347 | # By default, it will run forever every time the specified condition is detected 348 | # Detect 10mv of change polling 10 times a second. 349 | p9_33.run_on_change(callback, 10, 0.1) 350 | 351 | # This code will run immediately after the previous call, as it does not block 352 | sleep 20 353 | 354 | # Stop the background thread after 20 seconds 355 | p9_33.stop_wait 356 | ``` 357 | 358 | #### Waiting for Threshold 359 | To wait for the value of an analog pin to cross certain threshold voltages, the method **#wait_for_threshold** is used. 360 | 361 | **#wait_for_threshold** takes the following arguments. 362 | - mv_lower: The lower threshold value in millivolts 363 | - mv_upper: The upper threshold value in millivolts 364 | - mv_reset: The voltage change required to cross out of the lower or upper threshold ranges. 365 | - interval: How often to poll the value of the pin in seconds 366 | - mv_last: (optional) The initial value to use as a point to detect change 367 | - state_last: (optional) The initial state to use as a point to detect change 368 | 369 | Three states are available. 370 | - :LOW: below or equal to mv_lower 371 | - :MID: above mv_lower and below mv_upper 372 | - :HIGH: above or equal to mv_upper 373 | 374 | This method returns an array containing the initial voltage, the last polled voltage, the initial state, the last polled state, and the number of times the pin was polled. 375 | 376 | ```ruby 377 | # Initialize pin P9_33 for Analog Input 378 | p9_33 = AINPin.new(:P9_33) 379 | 380 | # Wait for the voltage on pin P9_33 to go below 200mv or above 1600mv. 381 | # To enter the :MID state from :HIGH or :LOW, it will have to cross the thresholds by at least 100mv. 382 | # Poll 10 times a second 383 | data = p9_33.wait_for_threshold(200, 1600, 100, 0.1) => [ 500, 150, :MID, :LOW, 53 ] 384 | 385 | # Assign variables from array 386 | mv_start, mv_current, state_start, state_current, count = data 387 | ``` 388 | 389 | #### Waiting for Threshold in the Background 390 | To avoid blocking while waiting for a voltage threshold to be crossed, the method **#run_on_threshold** will run a callback every time the specified change is detected. This method will spawn a new thread and wait for change in the background. The method **#run_once_on_threshold** is a convenience method to only be triggered once. Only one of these threads may be active per pin. 391 | 392 | This example waits for voltage change in the background and outputs information when the specified threshold is crossed. 393 | 394 | ```ruby 395 | # Initialize pin P9_33 for Analog Input 396 | p9_33 = AINPin.new(:P9_33) 397 | 398 | # Define callback to run when condition is met 399 | # This method takes 6 arguments. 400 | # pin: The pin that triggered the event 401 | # mv_last: The initial voltage used to determine change 402 | # mv: The current voltage on the pin 403 | # state_last: The initial state to use as a point to detect change 404 | # state: The current state of the pin 405 | # count: How many times it has been triggered 406 | callback = lambda { |pin, mv_last, mv, state_last, state, count| 407 | puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 408 | } 409 | 410 | # Run the callback every time the specified voltage threshold is crossed 411 | # This method has one additional argument that is optional. 412 | # Repeats: How many times to will run the event 413 | # By default, it will run forever every time the specified condition is detected 414 | # Wait for the voltage on pin P9_33 to go below 200mv or above 1600mv. 415 | # To enter the :MID state from :HIGH or :LOW, it will have to cross the thresholds by at least 100mv. 416 | # Poll 10 times a second 417 | # Run callback when state changes 418 | p9_33.run_on_threshold(callback, 200, 1600, 100, 0.1) 419 | 420 | # This code will run immediately after the previous call, as it does not block 421 | sleep 20 422 | 423 | # Stop the background thread after 20 seconds 424 | p9_33.stop_wait 425 | ``` 426 | 427 | ### PWM 428 | The beaglebone supports PWM (pulse width modulated) output on certain pins. These pins output 3.3v. The output is controlled based on frequency and duty cycle. 429 | 430 | To initialize the pin **P9_14**, pass the symbol for that pin, the duty cycle, and the frequency in Hz to the **PWMPin** constructor. 431 | 432 | This example shows how to control PWM output of a specified pin. 433 | 434 | ```ruby 435 | # Initialize pin P9_14 for PWM output 436 | # This pin will now output a square wave at 10Hz with a 90% duty cycle, non-inverted. 437 | p9_14 = PWMPin.new(:P9_14, 90, 10, :NORMAL) 438 | 439 | # Change frequency to 20Hz. Duty cycle remains 90% 440 | p9_14.set_frequency(20) 441 | 442 | # Change the duty cycle to 50% 443 | p9_14.set_duty_cycle(50) 444 | 445 | # Adjust the frequency by setting the period in nanoseconds. 446 | p9_14.set_period_ns(31250000) 447 | 448 | # Adjust the duty cycle by setting the period in nanoseconds. 449 | p9_14.set_duty_cycle_ns(31250000) 450 | 451 | # Invert the output signal 452 | p9_14.set_polarity(:INVERTED) 453 | 454 | # Stop the output signal 455 | p9_14.stop 456 | 457 | # Resume the output signal 458 | p9_14.run 459 | 460 | # Disable the output signal 461 | p9_14.disable_pwm_pin 462 | ``` 463 | 464 | ### UART 465 | The beaglebone has a number of UART devices. These operate in TTL mode at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 466 | 467 | Please note, UART3 does not have an RX pin, and UART5 is only available if the HDMI device tree is not enabled. 468 | 469 | To initialize the UART device **UART1**, pass the symbol for that device and the speed to the **UARTDevice** constructor. 470 | 471 | ```ruby 472 | # Initialize the pins for device UART1 into UART mode. 473 | uart1 = UARTDevice.new(:UART1, 9600) 474 | 475 | # Change the speed of a UART device by calling #set_speed 476 | uart1.set_speed(115200) 477 | 478 | # Disable UART device 479 | uart1.disable 480 | ``` 481 | 482 | #### UART Writing 483 | Writing to a UART device is accomplished by calling the **#write** or **#writeln** methods 484 | ```ruby 485 | # Initialize the pins for device UART1 into UART mode. 486 | uart1 = UARTDevice.new(:UART1, 9600) 487 | 488 | # Write data to a UART1 489 | uart1.write("DATA DATA DATA!") 490 | 491 | # Write data to UART1 followed by a line feed 492 | uart1.writeln("A line feed follows") 493 | ``` 494 | 495 | #### UART Reading 496 | There are many methods available for reading from UART devices. These are blocking methods and will not return until the requested data is available. 497 | 498 | ```ruby 499 | # Initialize the pins for device UART1 into UART mode. 500 | uart1 = UARTDevice.new(:UART1, 9600) 501 | 502 | # Read one character from UART1 503 | c = uart1.readchar => "X" 504 | 505 | # Read 10 characters from UART1 506 | str = uart1.readchars(10) => "0123456789" 507 | 508 | # Read a line from UART1 509 | line = uart1.readline => "All the text up until the linefeed" 510 | ``` 511 | 512 | #### UART Reading and Iterating 513 | Data read from the UART device may be iterated with the following methods. These are blocking methods and will run until the loop is broken. 514 | 515 | ```ruby 516 | # Initialize the pins for device UART1 into UART mode. 517 | uart1 = UARTDevice.new(:UART1, 9600) 518 | 519 | # Run block on every character read from UART1 520 | uart1.each_char { |c| puts c } 521 | 522 | # Run block on every 5 character read from UART1 523 | uart1.each_char(5) { |str| puts str } 524 | 525 | # Run block on each line read from UART1 526 | uart1.each_line { |line| puts line } 527 | ``` 528 | 529 | #### UART Reading and Iterating in the Background 530 | Data read from the UART device may be iterated in the background with the following methods. The data read is passed to the specified callback. These method will spawn a new thread and wait for data in the background. Only one of these threads may be active per pin. 531 | 532 | This example shows various methods of reading and processing data read from UART1 in the background. 533 | 534 | ```ruby 535 | # Initialize the pins for device UART1 into UART mode. 536 | uart1 = UARTDevice.new(:UART1, 9600) 537 | 538 | # Define the callback to be run. It takes 3 arguments 539 | # uart: the UART device that triggered the callback 540 | # data: the data read from the UART 541 | # count: how many times this was triggered 542 | callback = lambda { |uart, data, count| puts "[#{uart}:#{count}] #{data}" } 543 | 544 | # Run callback for every character read 545 | uart1.run_on_each_char(callback) 546 | 547 | # Run callback for every 3 characters read 548 | uart1.run_on_each_chars(callback, 3) 549 | 550 | # Run callback for every line read 551 | uart1.run_on_each_line(callback) 552 | 553 | # Run callback once after a character is read 554 | uart1.run_once_on_each_char(callback) 555 | 556 | # Run callback once after 3 characters are read 557 | uart1.run_once_on_each_chars(callback, 3) 558 | 559 | # Run callback once after reading a line 560 | uart1.run_once_on_each_line(callback) 561 | 562 | # Stop the currently running background thread 563 | uart1.stop_read_wait 564 | ``` 565 | 566 | ### I2C 567 | The beaglebone has a number of I2C devices. These operate at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 568 | 569 | To initialize the I2C device **I2C2**, pass the symbol for that device to the **I2CDevice** constructor. 570 | 571 | ```ruby 572 | # Initialize I2C device I2C2 573 | i2c = I2CDevice.new(:I2C2) 574 | ``` 575 | 576 | #### I2C Writing 577 | To write to an I2C device, the method **#write** is used. 578 | 579 | **#write** takes the following arguments. 580 | - address: address of slave device 581 | - data: data to write 582 | 583 | #### I2C Reading 584 | To read from an I2C device, the method **#read** is used. 585 | 586 | **#read** takes the following arguments. 587 | - address: address of slave device 588 | - bytes: bytes to read 589 | - register: (optional) register to start reading from 590 | 591 | #### LSM303DLHC Example 592 | 593 | This example communicates with an [LSM303DLHC](https://www.adafruit.com/products/1120) Accelerometer/Compass/Thermometer device. 594 | 595 | ```ruby 596 | #!/usr/bin/env ruby 597 | require 'beaglebone' 598 | include Beaglebone 599 | 600 | # Initialize I2C device I2C2 601 | i2c = I2CDevice.new(:I2C2) 602 | 603 | # Put compass into continuous conversation mode 604 | i2c.write(0x1e, [0x02, 0x00].pack("C*")) 605 | 606 | # Enable temperatuer sensor, 15hz register update 607 | i2c.write(0x1e, [0x00, 0b10010000].pack("C*") ) 608 | 609 | # Delay for the settings to take effect 610 | sleep(0.1) 611 | 612 | # Read axis data. It is made up of 3 big endian signed shorts starting at register 0x03 613 | raw = i2c.read(0x1e, 6, [0x03].pack("C*")) 614 | 615 | # Coordinates are big endian signed shorts in x,z,y order 616 | x,z,y = raw.unpack("s>*") 617 | 618 | # Calculate angle of degrees from North 619 | degrees = (Math::atan2(y, x) * 180) / Math::PI 620 | degrees += 360 if degrees < 0 621 | 622 | # Read 2 byte big endian signed short from temperature register 623 | raw = i2c.read(0x1e, 2, [0x31].pack("C*")) 624 | 625 | # Temperature is sent big endian, least significant digit last 626 | temp = raw.unpack("s>").first 627 | 628 | # Temperature data is 12 bits, last 4 are unused 629 | temp = temp >> 4 630 | 631 | # Each bit is 8c 632 | temp /= 8 633 | 634 | # Correction factor 635 | temp += 18 636 | 637 | # Convert to f 638 | temp = (temp * 1.8 + 32).to_i 639 | 640 | # Output data 641 | puts "#{Time.now.strftime("%H:%M")} Temperature: #{temp} degrees f Direction: #{degrees.to_i} degrees" 642 | 643 | # Disable I2C device 644 | i2c.disable 645 | ``` 646 | 647 | ### SPI 648 | The beaglebone has a number of SPI devices. These operate at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 649 | 650 | To initialize the SPI device **SPI0**, pass the symbol for that device to the **SPIDevice** constructor. 651 | 652 | The optional arguments are available 653 | - mode: SPI mode, :SPI_MODE_0 through :SPI_MODE_3 654 | - speed: Speed of the SPI device 655 | - bpw: Bits per word 656 | 657 | ```ruby 658 | # Initialize SPI device SPI0 659 | spi = SPIDevice.new(:SPI0, :SPI_MODE_0, 1000000, 8) 660 | 661 | # You can change SPI with the methods below. 662 | 663 | # Set mode of SPI0 664 | spi.set_mode(:SPI_MODE_3) 665 | 666 | # Set speed of SPI0 667 | spi.set_speed(100000) 668 | 669 | # Set bits per word of SPI0 670 | spi.set_bpw(10) 671 | 672 | # Disable SPI device 673 | spi.disable 674 | ``` 675 | 676 | #### SPI Data Transfer 677 | To transfer data to an SPI device, the method **#xfer** is used. 678 | 679 | **#xfer** takes the following arguments 680 | - tx_data: data to transmit 681 | - readbytes: (optional) number of bytes to read, otherwise it sizeof tx_data is used 682 | - speed: (optional) speed of the transfer 683 | - delay: (optional) delay 684 | - bpw: (optonal) bits per word 685 | 686 | **#xfer** returns the data read from the SPI device. 687 | 688 | #### MCP3008 Example 689 | This example communicates with an [MCP3008](http://www.adafruit.com/products/856) ADC device. 690 | 691 | ```ruby 692 | #!/usr/bin/env ruby 693 | require 'beaglebone' 694 | include Beaglebone 695 | 696 | # Initialize SPI device SPI0 697 | spi = SPIDevice.new(:SPI0) 698 | 699 | # communicate with MCP3008 700 | # byte 1: start bit 701 | # byte 2: single(1)/diff(0),3 bites for channel, null pad 702 | # byte 3: don't care 703 | # Read value from channel 0 704 | raw = spi.xfer([ 0b00000001, 0b10000000, 0].pack("C*")) 705 | 706 | # Split data read into an array of characters 707 | data = raw.unpack("C*") 708 | 709 | # The returned data is stored starting at the last two bits of the second byte 710 | val = ((data[1] & 0b00000011) << 8 ) | data[2] 711 | 712 | # Display the value of channel 0 713 | puts "Value of channel 0: #{val}" 714 | 715 | # Read value from channel 1 716 | raw = spi.xfer([ 0b00000001, 0b10010000, 0].pack("C*")) 717 | 718 | # Split data read into an array of characters 719 | data = raw.unpack("C*") 720 | 721 | # The returned data is stored starting at the last two bits of the second byte 722 | val = ((data[1] & 0b00000011) << 8 ) | data[2] 723 | 724 | # Display the value of channel 1 725 | puts "Value of channel 1: #{val}" 726 | 727 | # Disable SPI device 728 | spi.disable 729 | ``` 730 | 731 | ## Examples (Procedural) 732 | This library supports _procedural_ methods as well as _object oriented_ methods. They are virtually identical to the _object oriented_ methods, except the first argument they take is the pin. If a callback is required, it is still passed first, before the pin. 733 | 734 | The procedural versions of the examples are available in the file [procedural-examples.md](procedural-examples.md). 735 | 736 | Instead of constructors, the following methods are used to initialize the pins and devices on the Beaglebone. 737 | 738 | ```ruby 739 | # GPIOPin.new becomes 740 | GPIO.pin_mode(:P9_12, :OUT) 741 | 742 | # To set the state of the pin 743 | GPIO.digital_write(:P9_12, :OUT) 744 | 745 | # Analog pins do not require setup, and can be read at any time 746 | AIN.read(:P9_33) 747 | 748 | # PWMPin.new becomes 749 | PWM.start(:P9_14, 90, 10, :NORMAL) 750 | 751 | # UARTDevice.new becomes 752 | UART.setup(:UART1, 9600) 753 | 754 | # I2CDevice.new becomes 755 | I2C.setup(:I2C2) 756 | 757 | # SPIDevice.new becomes 758 | SPI.setup(:SPI0) 759 | ``` 760 | 761 | ## License 762 | Copyright (c) 2014 Rob Mosher. Distributed under the GPL-v3 License. See [LICENSE](LICENSE) for more information. 763 | -------------------------------------------------------------------------------- /beaglebone.gemspec: -------------------------------------------------------------------------------- 1 | Gem::Specification.new do |s| 2 | s.name = 'beaglebone' 3 | s.version = '1.2.6' 4 | s.date = '2015-03-01' 5 | s.summary = 'Beaglebone IO Gem' 6 | s.description = 'A Full Featured Beaglebone IO Gem' 7 | s.author = 'Rob Mosher' 8 | s.email = 'nyt-rubygems@countercultured.net' 9 | s.files = `git ls-files`.split("\n") 10 | s.homepage = 'https://github.com/notnyt/beaglebone' 11 | s.license = 'GPL-3.0' 12 | end 13 | -------------------------------------------------------------------------------- /lib/beaglebone.rb: -------------------------------------------------------------------------------- 1 | require 'beaglebone/beaglebone' 2 | require 'beaglebone/spi' 3 | require 'beaglebone/i2c' 4 | require 'beaglebone/uart' 5 | require 'beaglebone/pwm' 6 | require 'beaglebone/ain' 7 | require 'beaglebone/gpio' 8 | require 'beaglebone/shiftregister' 9 | -------------------------------------------------------------------------------- /lib/beaglebone/ain.rb: -------------------------------------------------------------------------------- 1 | # == ain.rb 2 | # This file contains the Analog Input methods 3 | module Beaglebone #:nodoc: 4 | # == AIN 5 | # procedural methods for Analog Input 6 | # == Summary 7 | # #read is called to get the analog value of a pin. 8 | # More advanced polling methods are also available 9 | module AIN 10 | class << self 11 | 12 | # valid voltage readings in mv 13 | RANGE = (0..1799) 14 | 15 | # Read from an analog pin 16 | # 17 | # @param pin should be a symbol representing the header pin 18 | # 19 | # @return [Integer] value in millivolts 20 | # 21 | # @example 22 | # AIN.read(:P9_33) => 1799 23 | def read(pin) 24 | Beaglebone::check_valid_pin(pin, :analog) 25 | 26 | Beaglebone::set_pin_status(pin, :type, :analog) 27 | 28 | ain_fd = Beaglebone::get_pin_status(pin, :fd_ain) 29 | 30 | unless ain_fd 31 | #ensure dtb is loaded 32 | Beaglebone::device_tree_load(TREES[:ADC][:global]) 33 | 34 | #open the AIN analog input file 35 | pininfo = PINS[pin] 36 | 37 | ain_file = Dir.glob("/sys/devices/ocp.*/helper.*/AIN#{pininfo[:analog]}").first 38 | #ain_file = Dir.glob("/sys/bus/iio/devices/iio:device0/in_voltage#{pininfo[:analog]}_raw").first 39 | ain_fd = File.open(ain_file, 'r') 40 | 41 | Beaglebone::set_pin_status(pin, :fd_ain, ain_fd) 42 | end 43 | 44 | ain_fd.rewind 45 | ain_fd.read.strip.to_i 46 | end 47 | 48 | # Runs a callback after voltage changes by specified amount. 49 | # This creates a new thread that runs in the background and polls at specified interval. 50 | # 51 | # @param callback A method to call when the change is detected. This method should take 4 arguments: the pin, the previous voltage, the current voltage, and the counter 52 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 53 | # @param mv_change an integer specifying the required change in mv 54 | # @param interval a number representing the wait time between polling 55 | # @param repeats is optional and specifies the number of times the callback will be run 56 | # 57 | # @example 58 | # This polls every 0.1 seconds and will run after a 10mv change is detected 59 | # callback = lambda { |pin, mv_last, mv, count| puts "[#{count}] #{pin} #{mv_last} -> #{mv}" } 60 | # AIN.run_on_change(callback, :P9_33, 10, 0.1) 61 | def run_on_change(callback, pin, mv_change=10, interval=0.01, repeats=nil) 62 | 63 | raise StandardError, "Already waiting for change on pin: #{pin}" if Beaglebone::get_pin_status(pin, :waiting) 64 | raise StandardError, "Already waiting for thread on pin: #{pin}" if Beaglebone::get_pin_status(pin, :thread) 65 | 66 | thread = Thread.new(callback, pin, mv_change, interval, repeats) do |c, p, mvc, i, r| 67 | begin 68 | count = 0 69 | mvl = nil 70 | loop do 71 | 72 | mvl,mv,itr = wait_for_change(p, mvc, i, mvl) 73 | 74 | c.call(p, mvl, mv, count) if c 75 | 76 | #if there was no delay in the wait_for_change, delay now. 77 | sleep(interval) if itr == 0 78 | 79 | mvl = mv 80 | count += 1 81 | break if r && count >= r 82 | end 83 | rescue => ex 84 | puts ex 85 | puts ex.backtrace 86 | ensure 87 | Beaglebone::delete_pin_status(p, :thread) 88 | Beaglebone::delete_pin_status(p, :waiting) 89 | end 90 | end 91 | 92 | Beaglebone::set_pin_status(pin, :thread, thread) 93 | end 94 | 95 | # Runs a callback once after specified change in voltage detected 96 | # Convenience method for run_on_change 97 | # @see #run_on_change 98 | def run_once_on_change(callback, pin, mv_change=10, interval=0.01) 99 | run_on_change(callback, pin, mv_change, interval, 1) 100 | end 101 | 102 | # Runs a callback after voltage changes beyond a certain threshold. 103 | # This creates a new thread that runs in the background and polls at specified interval. 104 | # When the voltage crosses the specified thresholds the callback is run. 105 | # 106 | # @param callback A method to call when the change is detected. This method should take 6 arguments: the pin, the previous voltage, the current voltage, the previous state, the current state, and the counter 107 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 108 | # @param mv_lower an integer specifying the lower threshold voltage 109 | # @param mv_upper an integer specifying the upper threshold voltage 110 | # @param mv_reset an integer specifying the range in mv required to reset the threshold trigger 111 | # @param interval a number representing the wait time between polling 112 | # @param repeats is optional and specifies the number of times the callback will be run 113 | # @example 114 | # # This polls every 0.01 seconds and will run after a the voltage crosses 400mv or 1200mv. 115 | # Voltage will have to cross a range by at least 5mv to prevent rapidly triggering events 116 | # callback = lambda { |pin, mv_last, mv, state_last, state, count| 117 | # puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 118 | # } 119 | # AIN.run_on_threshold(callback, :P9_33, 400, 1200, 5, 0.01) 120 | def run_on_threshold(callback, pin, mv_lower, mv_upper, mv_reset=10, interval=0.01, repeats=nil) 121 | 122 | raise StandardError, "Already waiting for change on pin: #{pin}" if Beaglebone::get_pin_status(pin, :waiting) 123 | raise StandardError, "Already waiting for thread on pin: #{pin}" if Beaglebone::get_pin_status(pin, :thread) 124 | 125 | thread = Thread.new(callback, pin, mv_lower, mv_upper, mv_reset, interval, repeats) do |c, p, mvl, mvu, mvr, i, r| 126 | begin 127 | count = 0 128 | mv_last = nil 129 | state_last = nil 130 | loop do 131 | 132 | mv_last,mv,state_last,state,itr = wait_for_threshold(p, mvl, mvu, mvr, i, mv_last, state_last) 133 | 134 | c.call(p, mv_last, mv, state_last, state, count) if c 135 | 136 | #if there was no delay in the wait_for_change, delay now. 137 | sleep(interval) if itr == 0 138 | 139 | mv_last = mv 140 | state_last = state 141 | count += 1 142 | break if r && r >= count 143 | end 144 | rescue => ex 145 | puts ex 146 | puts ex.backtrace 147 | ensure 148 | Beaglebone::delete_pin_status(p, :thread) 149 | Beaglebone::delete_pin_status(p, :waiting) 150 | end 151 | end 152 | 153 | Beaglebone::set_pin_status(pin, :thread, thread) 154 | end 155 | 156 | # Runs a callback once after voltage crosses a specified threshold. 157 | # Convenience method for run_on_threshold 158 | # @see #run_on_threshold 159 | def run_once_on_threshold(callback, pin, mv_lower, mv_upper, mv_reset=10, interval=0.01) 160 | run_on_threshold(callback, pin, mv_lower, mv_upper, mv_reset, interval, 1) 161 | end 162 | 163 | # noinspection RubyScope 164 | 165 | # Runs a callback after voltage changes beyond a certain threshold. 166 | # This creates a new thread that runs in the background and polls at specified interval. 167 | # When the voltage crosses the specified thresholds the callback is run. 168 | # 169 | # This method should take 6 arguments: 170 | # the pin, the previous voltage, the current voltage, the previous state, the current state, and the counter 171 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 172 | # @param mv_lower an integer specifying the lower threshold voltage 173 | # @param mv_upper an integer specifying the upper threshold voltage 174 | # @param mv_reset an integer specifying the range in mv required to reset the threshold trigger 175 | # @param interval a number representing the wait time between polling 176 | # @param mv_last is optional and specifies the voltage to use as the initial point to measure change 177 | # @param state_last is optional and specifies the state to use as the initial state to watch change 178 | # 179 | # @example 180 | # # This polls every 0.01 seconds and will run after a the voltage crosses 400mv or 1200mv. 181 | # # Voltage will have to cross a range by at least 5mv to prevent rapidly triggering events 182 | # callback = lambda { |pin, mv_last, mv, state_last, state, count| 183 | # puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 184 | # } 185 | # AIN.run_on_threshold(callback, :P9_33, 400, 1200, 5, 0.01) 186 | def wait_for_threshold(pin, mv_lower, mv_upper, mv_reset=10, interval=0.01, mv_last=nil, state_last=nil) 187 | Beaglebone::check_valid_pin(pin, :analog) 188 | raise ArgumentError, "mv_upper needs to be between 0 and 1800: #{pin} (#{mv_upper})" unless (0..1800).include?(mv_upper) 189 | raise ArgumentError, "mv_lower needs to be between 0 and 1800: #{pin} (#{mv_lower})" unless (0..1800).include?(mv_lower) 190 | raise ArgumentError, "mv_lower needs to be <= mv_upper: #{pin} (#{mv_lower}:#{mv_upper})" unless mv_lower <= mv_upper 191 | raise ArgumentError, "mv_reset needs to be between 0 and 1800: #{pin} (#{mv_reset})" unless (0..1800).include?(mv_reset) 192 | 193 | #ensure we're the only ones waiting for this trigger 194 | if Beaglebone::get_pin_status(pin, :thread) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 195 | raise StandardError, "Already waiting for change on pin: #{pin}" 196 | end 197 | 198 | if Beaglebone::get_pin_status(pin, :waiting) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 199 | raise StandardError, "Already waiting for change on pin: #{pin}" 200 | end 201 | 202 | Beaglebone::set_pin_status(pin, :waiting, true) 203 | 204 | mv_last = read(pin) unless mv_last 205 | 206 | if mv_last >= mv_upper 207 | state_last = :HIGH 208 | elsif mv_last <= mv_lower 209 | state_last = :LOW 210 | else 211 | state_last = :MID 212 | end unless state_last 213 | 214 | state = :UNKNOWN 215 | count = 0 216 | loop do 217 | mv = read(pin) 218 | 219 | if state_last == :LOW 220 | #state remains low unless it crosses into high, or above mv_low + mv_reset 221 | if mv >= mv_upper && mv >= mv_lower + mv_reset 222 | state = :HIGH 223 | elsif mv >= mv_lower + mv_reset 224 | state = :MID 225 | else 226 | state = :LOW 227 | end 228 | elsif state_last == :HIGH 229 | #state remains high unless it crosses into low, or below mv_high - mv_reset 230 | if mv <= mv_lower && mv <= mv_upper - mv_reset 231 | state = :LOW 232 | elsif mv <= mv_upper - mv_reset 233 | state = :MID 234 | else 235 | state = :HIGH 236 | end 237 | elsif state_last == :MID 238 | #state changes from normal by crossing into upper or lower 239 | if mv >= mv_upper 240 | state = :HIGH 241 | elsif mv <= mv_lower 242 | state = :LOW 243 | else 244 | state = :MID 245 | end 246 | end 247 | 248 | #if we've detected a change of state 249 | if state != state_last 250 | Beaglebone::delete_pin_status(pin, :waiting) 251 | return [ mv_last, mv, state_last, state, count ] 252 | end 253 | 254 | sleep interval 255 | 256 | count += 1 257 | end 258 | 259 | Beaglebone::delete_pin_status(pin, :waiting) 260 | [ mv_last, -1, state_last, state_last, count ] 261 | 262 | end 263 | 264 | # Returns when voltage changes by specified amount 265 | # 266 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 267 | # @param mv_change an integer specifying the required change in mv 268 | # @param interval a number representing the wait time between polling 269 | # @param mv_last is optional and specifies the voltage to use as the initial point to measure change 270 | # 271 | # @example 272 | # # This will poll every P9_33 every 0.01 seconds until 10mv of change is detected 273 | # # This method will return the initial reading, final reading, and how many times it polled 274 | # AIN.wait_for_change(:P9_33, 10, 0.01) => [ 1200, 1210, 4] 275 | def wait_for_change(pin, mv_change, interval, mv_last=nil) 276 | 277 | Beaglebone::check_valid_pin(pin, :analog) 278 | raise ArgumentError, "mv_change needs to be between 0 and 1800: #{pin} (#{mv_change})" unless (0..1800).include?(mv_change) 279 | 280 | #ensure we're the only ones waiting for this trigger 281 | if Beaglebone::get_pin_status(pin, :thread) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 282 | raise StandardError, "Already waiting for change on pin: #{pin}" 283 | end 284 | 285 | if Beaglebone::get_pin_status(pin, :waiting) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 286 | raise StandardError, "Already waiting for change on pin: #{pin}" 287 | end 288 | 289 | 290 | Beaglebone::set_pin_status(pin, :waiting, true) 291 | mv_last = read(pin) unless mv_last 292 | 293 | change_max = [mv_last - 0, 1799 - mv_last].max 294 | 295 | mv_change = change_max if mv_change > change_max 296 | 297 | count = 0 298 | loop do 299 | mv = read(pin) 300 | 301 | #if we've detected the change or hit the edge of the range 302 | if (mv - mv_last).abs >= mv_change 303 | 304 | Beaglebone::delete_pin_status(pin, :waiting) 305 | return [ mv_last, mv, count ] 306 | end 307 | 308 | sleep interval 309 | 310 | count += 1 311 | end 312 | 313 | Beaglebone::delete_pin_status(pin, :waiting) 314 | [ mv_last, -1, count ] 315 | end 316 | 317 | # Stops any threads waiting for data on specified pin 318 | # 319 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 320 | def stop_wait(pin) 321 | thread = Beaglebone::get_pin_status(pin, :thread) 322 | 323 | thread.exit if thread 324 | thread.join if thread 325 | end 326 | 327 | # Return an array of AIN pins in use 328 | # 329 | # @return [Array] 330 | # 331 | # @example 332 | # AIN.get_analog_pins => [:P9_33, :P9_34] 333 | def get_analog_pins 334 | Beaglebone.pinstatus.clone.select { |x,y| x if y[:type] == :analog}.keys 335 | end 336 | 337 | # Disable an analog pin 338 | # 339 | # @param pin should be a symbol representing the header pin 340 | def disable_analog_pin(pin) 341 | Beaglebone::check_valid_pin(pin, :analog) 342 | Beaglebone::delete_pin_status(pin) 343 | end 344 | 345 | # Disable all analog pins 346 | def cleanup 347 | #reset all GPIO we've used to IN and unexport them 348 | get_analog_pins.each { |x| disable_analog_pin(x) } 349 | end 350 | 351 | end 352 | end 353 | 354 | # Object Oriented AIN Implementation. 355 | # This treats the pin as an object. 356 | class AINPin 357 | # Initialize a Analog pin 358 | # Return's an AINPin object 359 | # 360 | # @example 361 | # p9_33 = AINPin.new(:P9_33) 362 | def initialize(pin) 363 | @pin = pin 364 | end 365 | 366 | # Read from an analog pin 367 | # 368 | # @return [Integer] value in millivolts 369 | # 370 | # @example 371 | # p9_33 = AINPin.new(:P9_33) 372 | # p9_33.read => 1799 373 | def read 374 | AIN::read(@pin) 375 | end 376 | 377 | # Runs a callback after voltage changes by specified amount. 378 | # This creates a new thread that runs in the background and polls at specified interval. 379 | # 380 | # @param callback A method to call when the change is detected 381 | # This method should take 4 arguments: the pin, the previous voltage, the current voltage, and the counter 382 | # @param mv_change an integer specifying the required change in mv 383 | # @param interval a number representing the wait time between polling 384 | # @param repeats is optional and specifies the number of times the callback will be run 385 | # 386 | # @example 387 | # # This polls every 0.1 seconds and will run after a 10mv change is detected 388 | # callback = lambda { |pin, mv_last, mv, count| puts "[#{count}] #{pin} #{mv_last} -> #{mv}" } 389 | # p9_33 = AINPin.new(:P9_33) 390 | # p9_33.run_on_change(callback, 10, 0.1) 391 | def run_on_change(callback, mv_change=10, interval=0.01, repeats=nil) 392 | AIN::run_on_change(callback, @pin, mv_change, interval, repeats) 393 | end 394 | 395 | # Runs a callback once after specified change in voltage detected 396 | # Convenience method for run_on_change 397 | def run_once_on_change(callback, mv_change=10, interval=0.01) 398 | AIN::run_once_on_change(callback, @pin, mv_change, interval) 399 | end 400 | 401 | 402 | # Runs a callback after voltage changes beyond a certain threshold. 403 | # This creates a new thread that runs in the background and polls at specified interval. 404 | # When the voltage crosses the specified thresholds the callback is run. 405 | # 406 | # @param callback A method to call when the change is detected. This method should take 6 arguments: the pin, the previous voltage, the current voltage, the previous state, the current state, and the counter 407 | # @param mv_lower an integer specifying the lower threshold voltage 408 | # @param mv_upper an integer specifying the upper threshold voltage 409 | # @param mv_reset an integer specifying the range in mv required to reset the threshold trigger 410 | # @param interval a number representing the wait time between polling 411 | # @param repeats is optional and specifies the number of times the callback will be run 412 | # 413 | # @example 414 | # # This polls every 0.01 seconds and will run after a the voltage crosses 400mv or 1200mv. 415 | # # Voltage will have to cross a range by at least 5mv to prevent rapidly triggering events 416 | # callback = lambda { |pin, mv_last, mv, state_last, state, count| 417 | # puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 418 | # } 419 | # p9_33 = AINPin.new(:P9_33) 420 | # p9_33.run_on_threshold(callback, 400, 1200, 5, 0.01) 421 | def run_on_threshold(callback, mv_lower, mv_upper, mv_reset=10, interval=0.01, repeats=nil) 422 | AIN::run_on_threshold(callback, @pin, mv_lower, mv_upper, mv_reset, interval, repeats) 423 | end 424 | 425 | 426 | # Runs a callback once after voltage crosses a specified threshold. 427 | # Convenience method for run_on_threshold 428 | def run_once_on_threshold(callback, mv_lower, mv_upper, mv_reset=10, interval=0.01) 429 | AIN::run_once_on_threshold(callback, @pin, mv_lower, mv_upper, mv_reset, interval) 430 | end 431 | 432 | # Returns when voltage changes by specified amount 433 | # @param mv_lower an integer specifying the lower threshold voltage 434 | # @param mv_upper an integer specifying the upper threshold voltage 435 | # @param mv_reset an integer specifying the range in mv required to reset the threshold trigger 436 | # @param interval a number representing the wait time between polling 437 | # @param mv_last is optional and specifies the voltage to use as the initial point to measure change 438 | # @param state_last is optional and specifies the state to use as the initial state to watch change 439 | # 440 | # @example 441 | # # This polls every 0.01 seconds and will run after a the voltage crosses 400mv or 1200mv. 442 | # # Voltage will have to cross a range by at least 5mv to prevent rapidly triggering events 443 | # callback = lambda { |pin, mv_last, mv, state_last, state, count| 444 | # puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 445 | # } 446 | # p9_33 = AINPin.new(:P9_33) 447 | # p9_33.wait_for_threshold(400, 1200, 5, 0.01) 448 | def wait_for_threshold(mv_lower, mv_upper, mv_reset=10, interval=0.01, mv_last=nil, state_last=nil) 449 | AIN::wait_for_threshold(@pin, mv_lower, mv_upper, mv_reset, interval, mv_last, state_last) 450 | end 451 | 452 | # Returns when voltage changes by specified amount 453 | # 454 | # @param mv_change an integer specifying the required change in mv 455 | # @param interval a number representing the wait time between polling 456 | # @param mv_last is optional and specifies the voltage to use as the initial point to measure change 457 | # 458 | # @example 459 | # # This will poll every P9_33 every 0.01 seconds until 10mv of change is detected 460 | # # This method will return the initial reading, final reading, and how many times it polled 461 | # p9_33 = AINPin.new(:P9_33) 462 | # p9_33.wait_for_change(10, 0.01) => [ 1200, 1210, 4] 463 | def wait_for_change(mv_change, interval, mv_last=nil) 464 | AIN::wait_for_change(@pin, mv_change, interval, mv_last) 465 | end 466 | 467 | # Stops any threads waiting for data on this pin 468 | def stop_wait 469 | AIN::stop_wait(@pin) 470 | end 471 | 472 | # Disable analog pin 473 | def disable_analog_pin 474 | AIN::disable_analog_pin(@pin) 475 | end 476 | 477 | end 478 | end 479 | -------------------------------------------------------------------------------- /lib/beaglebone/beaglebone.rb: -------------------------------------------------------------------------------- 1 | # This is the main module for this gem. You generally do not want to call these methods directly. 2 | module Beaglebone 3 | # Hash of pins and their uses 4 | PINS = { 5 | :USR0 => { :gpio => 53, :led => 'usr0' }, 6 | :USR1 => { :gpio => 54, :led => 'usr1' }, 7 | :USR2 => { :gpio => 55, :led => 'usr2' }, 8 | :USR3 => { :gpio => 56, :led => 'usr3' }, 9 | 10 | :P8_1 => { :dgnd => 'Digital Ground' }, 11 | :P8_2 => { :dgnd => 'Digital Ground' }, 12 | 13 | :P8_3 => { :gpio => 38, :gpiofunc => 'gpio1_6', :muxoffset => '0x018', :mmc => 'mmc1_dat6' }, 14 | :P8_4 => { :gpio => 39, :gpiofunc => 'gpio1_7', :muxoffset => '0x01c', :mmc => 'mmc1_dat7' }, 15 | :P8_5 => { :gpio => 34, :gpiofunc => 'gpio1_2', :muxoffset => '0x008', :mmc => 'mmc1_dat2' }, 16 | :P8_6 => { :gpio => 35, :gpiofunc => 'gpio1_3', :muxoffset => '0x00c', :mmc => 'mmc1_dat3' }, 17 | 18 | :P8_7 => { :gpio => 66, :gpiofunc => 'gpio2_2', :muxoffset => '0x090', :timer => 'timer4' }, 19 | :P8_8 => { :gpio => 67, :gpiofunc => 'gpio2_3', :muxoffset => '0x094', :timer => 'timer7' }, 20 | :P8_9 => { :gpio => 69, :gpiofunc => 'gpio2_5', :muxoffset => '0x09c', :timer => 'timer5' }, 21 | :P8_10 => { :gpio => 68, :gpiofunc => 'gpio2_4', :muxoffset => '0x098', :timer => 'timer6' }, 22 | 23 | :P8_11 => { :gpio => 45, :gpiofunc => 'gpio1_13', :muxoffset => '0x034' }, 24 | :P8_12 => { :gpio => 44, :gpiofunc => 'gpio1_12', :muxoffset => '0x030' }, 25 | 26 | # You can emable PWM as listed below 27 | # P8_13 *OR* P8_19 (EHRPWM2B, EHRPWM2A), 28 | # P9_14 *OR* P9_16 (EHRPWM1A, EHRPWM1B), 29 | # P9_21 *OR* P9_22 (EHRPWM0B, EHRPWM0A). 30 | # there are also ecap pwms on pins P9_28 and P9_42 31 | 32 | :P8_13 => { :gpio => 23, :gpiofunc => 'gpio0_23', :muxoffset => '0x024', :pwm => 'pwm_2b', :pwm_id => 2, :pwm_mux => 4 }, 33 | 34 | :P8_14 => { :gpio => 26, :gpiofunc => 'gpio0_26', :muxoffset => '0x028' }, 35 | :P8_15 => { :gpio => 47, :gpiofunc => 'gpio1_15', :muxoffset => '0x03c' }, 36 | :P8_16 => { :gpio => 46, :gpiofunc => 'gpio1_14', :muxoffset => '0x038' }, 37 | :P8_17 => { :gpio => 27, :gpiofunc => 'gpio0_27', :muxoffset => '0x02c' }, 38 | :P8_18 => { :gpio => 65, :gpiofunc => 'gpio2_1', :muxoffset => '0x08c' }, 39 | 40 | :P8_19 => { :gpio => 22, :gpiofunc => 'gpio0_22', :muxoffset => '0x020', :pwm => 'pwm_2a', :pwm_id => 2, :pwm_mux => 4 }, 41 | 42 | # You can only use the mmc pins if booting from SD and disabling mmc 43 | # mmc reset behavior is unclear 44 | # Best option is to not use the MMC1_CLK and MMC1_CMD signals at all and tie them low. 45 | :P8_20 => { :gpio => 63, :gpiofunc => 'gpio1_31', :muxoffset => '0x084', :mmc => 'mmc1_cmd' }, 46 | :P8_21 => { :gpio => 62, :gpiofunc => 'gpio1_30', :muxoffset => '0x080', :mmc => 'mmc1_clk' }, 47 | :P8_22 => { :gpio => 37, :gpiofunc => 'gpio1_5', :muxoffset => '0x014', :mmc => 'mmc1_dat5' }, 48 | :P8_23 => { :gpio => 36, :gpiofunc => 'gpio1_4', :muxoffset => '0x010', :mmc => 'mmc1_dat4' }, 49 | :P8_24 => { :gpio => 33, :gpiofunc => 'gpio1_1', :muxoffset => '0x004', :mmc => 'mmc1_dat1' }, 50 | :P8_25 => { :gpio => 32, :gpiofunc => 'gpio1_0', :muxoffset => '0x000', :mmc => 'mmc1_dat0' }, 51 | 52 | :P8_26 => { :gpio => 61, :gpiofunc => 'gpio1_29', :muxoffset => '0x07c' }, 53 | :P8_27 => { :gpio => 86, :gpiofunc => 'gpio2_22', :muxoffset => '0x0e0', :lcd => 'lcd_vsync' }, 54 | :P8_28 => { :gpio => 88, :gpiofunc => 'gpio2_24', :muxoffset => '0x0e8', :lcd => 'lcd_pclk' }, 55 | :P8_29 => { :gpio => 87, :gpiofunc => 'gpio2_23', :muxoffset => '0x0e4', :lcd => 'lcd_hsync' }, 56 | :P8_30 => { :gpio => 89, :gpiofunc => 'gpio2_25', :muxoffset => '0x0ec', :lcd => 'lcd_ac_bias' }, 57 | :P8_31 => { :gpio => 10, :gpiofunc => 'gpio0_10', :muxoffset => '0x0d8', :lcd => 'lcd_data14', :uart => 'uart5_ctsn', :uart_id => 5 }, 58 | :P8_32 => { :gpio => 11, :gpiofunc => 'gpio0_11', :muxoffset => '0x0dc', :lcd => 'lcd_data15', :uart => 'uart5_rtsn', :uart_id => 5 }, 59 | :P8_33 => { :gpio => 9, :gpiofunc => 'gpio0_9', :muxoffset => '0x0d4', :lcd => 'lcd_data13', :uart => 'uart4_rtsn', :uart_id => 4 }, 60 | :P8_34 => { :gpio => 81, :gpiofunc => 'gpio2_17', :muxoffset => '0x0cc', :lcd => 'lcd_data11', :pwm => 'pwm_1b', :pwm_id => 1, :pwm_mux => 2, :uart => 'uart3_rtsn', :uart_id => 3 }, 61 | :P8_35 => { :gpio => 8, :gpiofunc => 'gpio0_8', :muxoffset => '0x0d0', :lcd => 'lcd_data12', :uart => 'uart4_ctsn' }, 62 | :P8_36 => { :gpio => 80, :gpiofunc => 'gpio2_16', :muxoffset => '0x0c8', :lcd => 'lcd_data10', :pwm => 'pwm_1a', :pwm_id => 1, :pwm_mux => 2, :uart => 'uart3_ctsn', :uart_id => 3 }, 63 | :P8_37 => { :gpio => 78, :gpiofunc => 'gpio2_14', :muxoffset => '0x0c0', :lcd => 'lcd_data8', :uart => 'uart5_txd', :uart_id => 5 }, 64 | :P8_38 => { :gpio => 79, :gpiofunc => 'gpio2_15', :muxoffset => '0x0c4', :lcd => 'lcd_data9', :uart => 'uart5_rxd', :uart_id => 5 }, 65 | :P8_39 => { :gpio => 76, :gpiofunc => 'gpio2_12', :muxoffset => '0x0b8', :lcd => 'lcd_data6' }, 66 | :P8_40 => { :gpio => 77, :gpiofunc => 'gpio2_13', :muxoffset => '0x0bc', :lcd => 'lcd_data7' }, 67 | :P8_41 => { :gpio => 74, :gpiofunc => 'gpio2_10', :muxoffset => '0x0b0', :lcd => 'lcd_data4' }, 68 | :P8_42 => { :gpio => 75, :gpiofunc => 'gpio2_11', :muxoffset => '0x0b4', :lcd => 'lcd_data5' }, 69 | :P8_43 => { :gpio => 72, :gpiofunc => 'gpio2_8', :muxoffset => '0x0a8', :lcd => 'lcd_data2' }, 70 | :P8_44 => { :gpio => 73, :gpiofunc => 'gpio2_9', :muxoffset => '0x0ac', :lcd => 'lcd_data3' }, 71 | :P8_45 => { :gpio => 70, :gpiofunc => 'gpio2_6', :muxoffset => '0x0a0', :lcd => 'lcd_data0', :pwm => 'pwm_2a', :pwm_id => 2, :pwm_mux => 3 }, 72 | :P8_46 => { :gpio => 71, :gpiofunc => 'gpio2_7', :muxoffset => '0x0a4', :lcd => 'lcd_data1', :pwm => 'pwm_2b', :pwm_id => 2, :pwm_mux => 3 }, 73 | 74 | :P9_1 => { :dgnd => 'ground' }, 75 | :P9_2 => { :dgnd => 'ground' }, 76 | :P9_3 => { :vdd_3v3 => '3.3 volts' }, 77 | :P9_4 => { :vdd_3v3 => '3.3 volts' }, 78 | :P9_5 => { :vdd_5v => '5 volts' }, 79 | :P9_6 => { :vdd_5v => '5 volts' }, 80 | :P9_7 => { :sys_5v => '5 volts' }, 81 | :P9_8 => { :sys_5v => '5 volts' }, 82 | :P9_9 => { :pwr_but => 'power button' }, 83 | :P9_10 => { :sys_resetn => 'reset button' }, 84 | 85 | :P9_11 => { :gpio => 30, :gpiofunc => 'gpio0_30', :muxoffset => '0x070', :uart => 'uart4_rxd', :uart_id => 4 }, 86 | :P9_12 => { :gpio => 60, :gpiofunc => 'gpio1_28', :muxoffset => '0x078' }, 87 | :P9_13 => { :gpio => 31, :gpiofunc => 'gpio0_31', :muxoffset => '0x074', :uart => 'uart4_txd', :uart_id => 4 }, 88 | :P9_14 => { :gpio => 50, :gpiofunc => 'gpio1_18', :muxoffset => '0x048', :pwm => 'pwm_1a', :pwm_id => 1, :pwm_mux => 6 }, 89 | :P9_15 => { :gpio => 48, :gpiofunc => 'gpio1_16', :muxoffset => '0x040' }, 90 | :P9_16 => { :gpio => 51, :gpiofunc => 'gpio1_19', :muxoffset => '0x04c', :pwm => 'pwm_1b', :pwm_id => 1, :pwm_mux => 6 }, 91 | :P9_17 => { :gpio => 5, :gpiofunc => 'gpio0_5', :muxoffset => '0x15c', :i2c => 'i2c1_scl', :i2c_id => 1, :spi => 'spi0_cs0', :spi_id => 0 }, 92 | :P9_18 => { :gpio => 4, :gpiofunc => 'gpio0_4', :muxoffset => '0x158', :i2c => 'i2c1_sda', :i2c_id => 1, :spi => 'spi0_d1', :spi_id => 0 }, 93 | :P9_19 => { :i2c => 'i2c2_scl', :i2c_id => 2, :uart => 'uart1_rtsn', :uart_id => 1, :spi => 'spi1_cs1', :spi_id => 1 }, 94 | :P9_20 => { :i2c => 'i2c2_sda', :i2c_id => 2, :uart => 'uart1_ctsn', :uart_id => 1, :spi => 'spi1_cs0', :spi_id => 1 }, 95 | :P9_21 => { :gpio => 3, :gpiofunc => 'gpio0_3', :muxoffset => '0x154', :pwm => 'pwm_0b', :pwm_id => 0, :pwm_mux => 3, :i2c => 'i2c2_scl', :i2c_id => 2, :uart => 'uart2_txd', :uart_id => 2, :spi => 'spi0_d0', :spi_id => 0 }, 96 | :P9_22 => { :gpio => 2, :gpiofunc => 'gpio0_2', :muxoffset => '0x150', :pwm => 'pwm_0a', :pwm_id => 0, :pwm_mux => 3, :i2c => 'i2c2_sda', :i2c_id => 2, :uart => 'uart2_rxd', :uart_id => 2, :spi => 'spi0_sclk', :spi_id => 0 }, 97 | :P9_23 => { :gpio => 49, :gpiofunc => 'gpio1_17', :muxoffset => '0x044' }, 98 | :P9_24 => { :gpio => 15, :gpiofunc => 'gpio0_15', :muxoffset => '0x184', :i2c => 'i2c1_scl', :i2c_id => 1, :uart => 'uart1_txd', :uart_id => 1 }, 99 | :P9_25 => { :gpio => 117, :gpiofunc => 'gpio3_21', :muxoffset => '0x1ac', :mcasp => 'mcasp0_ahclkx' }, 100 | :P9_26 => { :gpio => 14, :gpiofunc => 'gpio0_14', :muxoffset => '0x180', :i2c => 'i2c1_sda', :i2c_id => 2, :uart => 'uart1_rxd', :uart_id => 1 }, 101 | :P9_27 => { :gpio => 115, :gpiofunc => 'gpio3_19', :muxoffset => '0x1a4' }, 102 | :P9_28 => { :gpio => 113, :gpiofunc => 'gpio3_17', :muxoffset => '0x19c', :pwm => 'ecappwm2', :pwm_id => 3, :pwm_mux => 4, :ecap => 2, :spi => 'spi1_cs0', :spi_id => 1, :mcasp => 'mcasp0_ahclkr' }, 103 | :P9_29 => { :gpio => 111, :gpiofunc => 'gpio3_15', :muxoffset => '0x194', :pwm => 'pwm_0b', :pwm_id => 0, :pwm_mux => 1, :spi => 'spi1_d0', :spi_id => 1, :mcasp => 'mcasp0_fsx' }, 104 | :P9_30 => { :gpio => 112, :gpiofunc => 'gpio3_16', :muxoffset => '0x198', :spi => 'spi1_d1', :spi_id => 1 }, 105 | :P9_31 => { :gpio => 110, :gpiofunc => 'gpio3_14', :muxoffset => '0x190', :pwm => 'pwm_0a', :pwm_id => 0, :pwm_mux => 1, :spi => 'spi1_sclk', :spi_id => 1, :mcasp => 'mcasp0_aclkx' }, 106 | 107 | :P9_32 => { :vdd_adc => 'analog output 1.8v' }, 108 | :P9_33 => { :analog => 4 }, 109 | :P9_34 => { :gnda_adc => 'analog ground' }, 110 | :P9_35 => { :analog => 6 }, 111 | :P9_36 => { :analog => 5 }, 112 | :P9_37 => { :analog => 2 }, 113 | :P9_38 => { :analog => 3 }, 114 | :P9_39 => { :analog => 0 }, 115 | :P9_40 => { :analog => 1 }, 116 | 117 | :P9_41 => { :gpio => 20, :gpiofunc => 'gpio0_20', :muxoffset => '0x1b4' }, 118 | :P9_42 => { :gpio => 7, :gpiofunc => 'gpio0_7', :muxoffset => '0x164', :pwm => 'ecappwm0', :pwm_id => 4, :pwm_mux => 0, :ecap => 0, :uart => 'uart3_txd', :uart_id => 3, :spi => 'spi1_sclk', :spi_id => 1 }, 119 | :P9_43 => { :dgnd => 'ground' }, 120 | :P9_44 => { :dgnd => 'ground' }, 121 | :P9_45 => { :dgnd => 'ground' }, 122 | :P9_46 => { :dgnd => 'ground' }, 123 | }.freeze 124 | 125 | # Generic device trees 126 | TREES = { 127 | :GPIO => { :global => nil, :pin => 'GPIO_' }, 128 | :UART => { :global => nil, :pin => 'BB-UART' }, 129 | :ADC => { :global => 'BB-ADC', :pin => nil }, 130 | :PWM => { :global => 'am33xx_pwm', :pin => 'bone_pwm_' }, 131 | }.freeze 132 | 133 | # UART device hash 134 | UARTS = { 135 | :UART1 => { :id => 1, :rx => :P9_26, :tx => :P9_24, :dev => '/dev/ttyO1' }, 136 | :UART2 => { :id => 2, :rx => :P9_22, :tx => :P9_21, :dev => '/dev/ttyO2' }, 137 | :UART3 => { :id => 3, :rx => nil, :tx => :P9_42, :dev => '/dev/ttyO3' }, 138 | :UART4 => { :id => 4, :rx => :P9_11, :tx => :P9_13, :dev => '/dev/ttyO4' }, 139 | :UART5 => { :id => 5, :rx => :P8_38, :tx => :P8_37, :dev => '/dev/ttyO5' }, 140 | }.freeze 141 | 142 | # I2C device hash 143 | I2CS = { 144 | :I2C0 => { :id => 0, :dev => '/dev/i2c-0' }, 145 | :I2C1 => { :id => 2, :dev => '/dev/i2c-2', :scl => :P9_17, :sda => :P9_18, :devicetree => 'BB-I2C1' }, 146 | :I2C2 => { :id => 1, :dev => '/dev/i2c-1', :scl => :P9_19, :sda => :P9_20 }, 147 | #alternate pins for i2c1 148 | :I2C1A => { :id => 2, :dev => '/dev/i2c-2', :scl => :P9_24, :sda => :P9_26, :devicetree => 'BB-I2C1A1' }, 149 | }.freeze 150 | 151 | # SPI device hash 152 | SPIS = { 153 | :counter => 1, 154 | :SPI0 => { :id => 0, :dev => '/dev/spidev', :devicetree => 'BB-SPIDEV0', 155 | :cs0 => :P9_17, :sclk => :P9_22, :d0 => :P9_21, :d1 => :P9_18, 156 | :pins => [ :P9_17, :P9_18, :P9_21, :P9_22 ] }, 157 | 158 | :SPI1 => { :id => 1, :dev => '/dev/spidev', :devicetree => 'BB-SPIDEV1', 159 | :cs0 => :P9_28, :sclk => :P9_31, :d0 => :P9_29, :d1 => :P9_30, 160 | :pins => [ :P9_28, :P9_29, :P9_30, :P9_31 ] }, 161 | 162 | #alternate pins for SPI2 163 | :SPI1A => { :id => 1, :dev => '/dev/spidev', :devicetree => 'BB-SPIDEV1A1', 164 | :cs0 => :P9_20, :sclk => :P9_42, :d0 => :P9_29, :d1 => :P9_30, 165 | :pins => [ :P9_20, :P9_29, :P9_30, :P9_42 ] }, 166 | 167 | } 168 | 169 | @pinstatus = {} 170 | @pinmutex = Mutex.new 171 | @loaded_dtbs = [] 172 | 173 | class << self 174 | attr_accessor :pinstatus, :pinmutex, :loaded_dtbs 175 | 176 | # @private 177 | # get hash entry for pin 178 | def get_pin_status(pin, key = nil) 179 | pinmutex.synchronize do 180 | if key 181 | pinstatus[pin] ? pinstatus[pin][key] : nil 182 | else 183 | pinstatus[pin] 184 | end 185 | end 186 | end 187 | 188 | # @private 189 | # set hash entry for pin 190 | def set_pin_status(pin, key, value) 191 | pinmutex.synchronize do 192 | pinstatus[pin] ||= {} 193 | pinstatus[pin][key] = value 194 | end 195 | end 196 | 197 | # @private 198 | # delete pin's hash entry 199 | def delete_pin_status(pin, key = nil) 200 | pinmutex.synchronize do 201 | if key.nil? 202 | pinstatus.delete(pin) 203 | else 204 | pinstatus[pin].delete(key) if pinstatus[pin] 205 | end 206 | end 207 | end 208 | 209 | # disable pin 210 | def disable_pin(pin) 211 | status = get_pin_status(pin) 212 | 213 | if status 214 | case status[:type] 215 | when :gpio 216 | Beaglebone::GPIO.disable_gpio_pin(pin) 217 | when :pwm 218 | Beaglebone::PWM.disable_pwm_pin(pin) 219 | else 220 | #we can't disable any other pin types at this time 221 | raise StandardError, "Cannot disable pin: #{pin} in #{status[:type]} mode" 222 | end 223 | end 224 | end 225 | 226 | # check if a pin of given type is valid 227 | def check_valid_pin(pin, type = nil) 228 | #check to see if pin exists 229 | raise ArgumentError, "No such PIN: #{pin.to_s}" unless PINS[pin] 230 | 231 | if type 232 | raise StandardError, "Pin does not support #{type}: #{pin.to_s}" unless PINS[pin][type] 233 | end 234 | end 235 | 236 | # return capemgr directory 237 | def get_capemgr_dir 238 | Dir.glob([ '/sys/devices/bone_capemgr.*', '/sys/devices/platform/bone_capemgr' ]).first 239 | end 240 | 241 | # check if device tree is loaded 242 | def device_tree_loaded?(name) 243 | !!File.open("#{get_capemgr_dir}/slots").read.match(/,#{name}$/) 244 | end 245 | 246 | # load a device tree 247 | def device_tree_load(name, delay=0.25) 248 | return true if loaded_dtbs.include?(name) 249 | 250 | if device_tree_loaded?(name) 251 | loaded_dtbs << name 252 | return true 253 | end 254 | 255 | File.open("#{get_capemgr_dir}/slots", 'w') { |f| f.write(name) } 256 | sleep delay 257 | raise StandardError, "Unable to load device tree: #{name}" unless device_tree_loaded?(name) 258 | true 259 | end 260 | 261 | # unload a device tree, return false if not loaded, return true if it unloads 262 | def device_tree_unload(name) 263 | return false unless device_tree_loaded?(name) 264 | 265 | dtb_id = File.open("#{get_capemgr_dir}/slots", 'r').read.scan(/^ ?(\d+): .*?,#{name}/).flatten.first 266 | 267 | File.open("#{get_capemgr_dir}/slots", 'w') { |f| f.write("-#{dtb_id}") } 268 | 269 | raise StandardError, "Unable to unload device tree: #{name}" if device_tree_loaded?(name) 270 | 271 | true 272 | end 273 | 274 | # cleanup all the things 275 | def cleanup 276 | Beaglebone::AIN.cleanup 277 | Beaglebone::PWM.cleanup 278 | Beaglebone::GPIO.cleanup 279 | Beaglebone::UART.cleanup 280 | Beaglebone::I2C.cleanup 281 | Beaglebone::SPI.cleanup 282 | end 283 | end 284 | end 285 | 286 | -------------------------------------------------------------------------------- /lib/beaglebone/gpio.rb: -------------------------------------------------------------------------------- 1 | # == gpio.rb 2 | # This file contains the GPIO methods 3 | 4 | module Beaglebone #:nodoc: 5 | # == GPIO 6 | # procedural methods for GPIO control 7 | # == Summary 8 | # #pin_mode is called to initialize a pin. 9 | # Further basic functionality is available with #digital_read and #digital_write 10 | module GPIO 11 | class << self 12 | # GPIO modes 13 | MODES = [ :IN, :OUT ] 14 | # GPIO states 15 | STATES = { :HIGH => 1, :LOW => 0 } 16 | # Edge trigger options 17 | EDGES = [ :NONE, :RISING, :FALLING, :BOTH ] 18 | # Slew rates 19 | SLEWRATES = [ :SLOW, :FAST ] 20 | # pull modes 21 | PULLMODES = [ :PULLUP, :PULLDOWN, :NONE ] 22 | 23 | # dts template for GPIO pin 24 | GPIOTEMPLATE = '/* 25 | * This is a template-generated file 26 | */ 27 | 28 | /dts-v1/; 29 | /plugin/; 30 | 31 | /{ 32 | compatible = "ti,beaglebone", "ti,beaglebone-black"; 33 | part_number = "BS_PINMODE_!PIN_KEY!_!DATA!"; 34 | 35 | exclusive-use = 36 | "!PIN_DOT_KEY!", 37 | "!PIN_FUNCTION!"; 38 | 39 | fragment@0 { 40 | target = <&am33xx_pinmux>; 41 | __overlay__ { 42 | bs_pinmode_!PIN_KEY!_!DATA!: pinmux_bs_pinmode_!PIN_KEY!_!DATA! { 43 | pinctrl-single,pins = ; 44 | }; 45 | }; 46 | }; 47 | 48 | fragment@1 { 49 | target = <&ocp>; 50 | __overlay__ { 51 | bs_pinmode_!PIN_KEY!_!DATA!_pinmux { 52 | compatible = "bone-pinmux-helper"; 53 | status = "okay"; 54 | pinctrl-names = "default"; 55 | pinctrl-0 = <&bs_pinmode_!PIN_KEY!_!DATA!>; 56 | }; 57 | }; 58 | }; 59 | }; 60 | ' 61 | # Initialize a GPIO pin 62 | # 63 | # @param pin should be a symbol representing the header pin 64 | # @param mode should specify the mode of the pin, either :IN or :OUT 65 | # @param pullmode (optional) should specify the pull mode, :PULLUP, :PULLDOWN, or :NONE 66 | # @param slewrate (optional) should specify the slew rate, :FAST or :SLOW 67 | # @example 68 | # GPIO.pin_mode(:P9_12, :OUT) 69 | # GPIO.pin_mode(:P9_11, :IN, :PULLUP, :FAST) 70 | def pin_mode(pin, mode, pullmode = nil, slewrate = nil) 71 | 72 | #make sure a valid mode was passed 73 | check_valid_mode(mode) 74 | 75 | #make sure a valid pin was passed and that it supports GPIO 76 | Beaglebone::check_valid_pin(pin, :gpio) 77 | 78 | #get info from PINS hash 79 | pininfo = PINS[pin] 80 | 81 | #if pin is enabled for something else, disable it 82 | if Beaglebone::get_pin_status(pin) && Beaglebone::get_pin_status(pin, :type) != :gpio 83 | Beaglebone::disable_pin(pin) 84 | end 85 | 86 | pullmode = pullmode || :PULLUP 87 | slewrate = slewrate || :FAST 88 | 89 | raise ArgumentError, "Invalid Slew Rate (#{slewrate}) specified on: #{pin}" unless SLEWRATES.include?(slewrate) 90 | raise ArgumentError, "Invalid Pull Mode (#{pullmode}) specified on: #{pin}" unless PULLMODES.include?(pullmode) 91 | 92 | if mode == :IN and pullmode != :PULLUP and ( pininfo[:mmc] or pin == :P9_15 ) 93 | raise ArgumentError, "Invalid Pull mode specified for pin: #{pin} (#{pullmode})" 94 | end 95 | 96 | #export pin unless its an on board LED, if it isn't already exported 97 | if pininfo[:led] 98 | raise StandardError, "LEDs only support OUT mode: #{pin.to_s}" unless mode == :OUT 99 | File.open("#{gpio_directory(pin)}/trigger", 'w') { |f| f.write('gpio') } 100 | else 101 | # if pin is not an onboard LED 102 | 103 | # create device tree overlay for this pin, do not force rebuild 104 | pin_data = create_device_tree(pin, mode, pullmode, slewrate, false) 105 | 106 | # unload previous dtb if loaded 107 | begin 108 | Beaglebone::device_tree_unload("#{TREES[:GPIO][:pin]}#{pin}_.*") 109 | rescue 110 | # 111 | end 112 | 113 | # load device tree overlay 114 | Beaglebone::device_tree_load("#{TREES[:GPIO][:pin]}#{pin}_0x#{pin_data.to_s(16)}") 115 | 116 | # export gpio pin 117 | begin 118 | File.open('/sys/class/gpio/export', 'w') { |f| f.write pininfo[:gpio] } 119 | rescue 120 | # 121 | end 122 | 123 | #check to see if pin is GPIO enabled in /sys/class/gpio/ 124 | raise StandardError, "GPIO was unable to initalize pin: #{pin.to_s}" unless enabled?(pin) 125 | 126 | end unless Beaglebone::get_pin_status(pin, :type) == :gpio 127 | 128 | #set pin mode 129 | unless pininfo[:led] 130 | set_gpio_mode(pin, mode) 131 | dir = read_gpio_direction(pin) 132 | raise StandardError, "GPIO was unable to set mode: #{pin.to_s} to #{mode.to_s} (#{dir})" if mode != dir 133 | end 134 | 135 | Beaglebone::set_pin_status(pin, :mode, mode) 136 | end 137 | 138 | # Sets a pin's output state 139 | # 140 | # @param pin should be a symbol representing the header pin 141 | # @param state should be a symbol representin the state, :HIGH or :LOW 142 | # 143 | # @example 144 | # GPIO.digital_write(:P9_12, :HIGH) 145 | # GPIO.digital_write(:P9_12, :LOW) 146 | def digital_write(pin, state) 147 | check_valid_state(state) 148 | check_gpio_enabled(pin) 149 | 150 | raise StandardError, "PIN not in GPIO OUT mode: #{pin}" unless get_gpio_mode(pin) == :OUT 151 | 152 | fd = get_value_fd(pin) 153 | fd.write STATES[state.to_sym].to_s 154 | fd.flush 155 | Beaglebone::set_pin_status(pin, :state, state) 156 | end 157 | 158 | # Reads a pin's input state and return that value 159 | # 160 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 161 | # 162 | # @return [Symbol] :HIGH or :LOW 163 | # 164 | # @example 165 | # GPIO.digital_read(:P9_11) => :HIGH 166 | def digital_read(pin) 167 | check_gpio_enabled(pin) 168 | 169 | raise StandardError, "PIN not in GPIO IN mode: #{pin}" unless get_gpio_mode(pin) == :IN 170 | 171 | fd = get_value_fd(pin) 172 | fd.rewind 173 | value = fd.read.to_s.strip 174 | state = STATES.key(value.to_i) 175 | 176 | Beaglebone::set_pin_status(pin, :state, state) 177 | end 178 | 179 | # Runs a callback on an edge trigger event. 180 | # This creates a new thread that runs in the background 181 | # 182 | # @param callback A method to call when the edge trigger is detected. This method should take 3 arguments, the pin, the edge, and the counter 183 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 184 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 185 | # @param timeout is optional and specifies a time window to wait 186 | # @param repeats is optional and specifies the number of times the callback will be run 187 | # 188 | # @example 189 | # GPIO.run_on_edge(lambda { |pin,edge,count| puts "[#{count}] #{pin} -- #{edge}" }, :P9_11, :RISING) 190 | def run_on_edge(callback, pin, edge, timeout = nil, repeats=nil) 191 | 192 | raise StandardError, "Already waiting for trigger on pin: #{pin}" if Beaglebone::get_pin_status(pin, :trigger) 193 | raise StandardError, "Already waiting for trigger on pin: #{pin}" if Beaglebone::get_pin_status(pin, :thread) 194 | 195 | thread = Thread.new(callback, pin, edge, timeout, repeats) do |c, p, e, t, r| 196 | begin 197 | count = 0 198 | loop do 199 | 200 | state = wait_for_edge(p, e, t, false) 201 | 202 | c.call(p, state, count) if c 203 | count += 1 204 | break if r && count >= r 205 | end 206 | rescue => ex 207 | puts ex 208 | puts ex.backtrace 209 | ensure 210 | cleanup_edge_trigger(p) 211 | end 212 | end 213 | 214 | Beaglebone::set_pin_status(pin, :thread, thread) 215 | end 216 | 217 | # Runs a callback one time on an edge trigger event. 218 | # This is a convenience method for run_on_edge 219 | # @see #run_on_edge 220 | def run_once_on_edge(callback, pin, edge, timeout = nil) 221 | run_on_edge(callback, pin, edge, timeout, 1) 222 | end 223 | 224 | # Stops any threads waiting for data on specified pin 225 | # 226 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 227 | def stop_edge_wait(pin) 228 | thread = Beaglebone::get_pin_status(pin, :thread) 229 | 230 | thread.exit if thread 231 | thread.join if thread 232 | end 233 | 234 | # Wait for an edge trigger. 235 | # Returns the type that triggered the event, e.g. :RISING, :FALLING, :BOTH 236 | # 237 | # @returns [Symbol] :RISING, :FALLING, or :BOTH 238 | # 239 | # @param pin should be a symbol representing the header pin, i.e. :P9_11 240 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 241 | # @param timeout is optional and specifies a time window to wait 242 | # @param disable is optional. If set, edge trigger detection is cleared on return 243 | # 244 | # @example 245 | # wait_for_edge(:P9_11, :RISING, 30) => :RISING 246 | def wait_for_edge(pin, edge, timeout = nil, disable=true) 247 | check_valid_edge(edge) 248 | raise ArgumentError, "Cannot wait for edge trigger NONE: #{pin}" if edge.to_sym == :NONE 249 | 250 | check_gpio_enabled(pin) 251 | raise StandardError, "PIN not in GPIO IN mode: #{pin}" unless get_gpio_mode(pin) == :IN 252 | 253 | #ensure we're the only ones waiting for this trigger 254 | if Beaglebone::get_pin_status(pin, :thread) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 255 | raise StandardError, "Already waiting for trigger on pin: #{pin}" 256 | end 257 | 258 | if Beaglebone::get_pin_status(pin, :trigger) && Beaglebone::get_pin_status(pin, :thread) != Thread.current 259 | raise StandardError, "Already waiting for trigger on pin: #{pin}" 260 | end 261 | 262 | set_gpio_edge(pin, edge) 263 | 264 | fd = get_value_fd(pin) 265 | fd.read 266 | 267 | #select will return fd into the error set "es" if it recieves an interrupt 268 | _, _, es = IO.select(nil, nil, [fd], timeout) 269 | 270 | set_gpio_edge(pin, :NONE) if disable 271 | 272 | es ? digital_read(pin) : nil 273 | 274 | end 275 | 276 | # Resets all the GPIO pins that we have used and unexport them 277 | def cleanup 278 | get_gpio_pins.each { |x| disable_gpio_pin(x) } 279 | end 280 | 281 | # Returns true if specified pin is enabled in GPIO mode, else false 282 | def enabled?(pin) 283 | 284 | return true if Beaglebone::get_pin_status(pin, :type) == :gpio 285 | 286 | return false unless valid?(pin) 287 | if Dir.exists?(gpio_directory(pin)) 288 | 289 | Beaglebone::set_pin_status(pin, :type, :gpio) 290 | return true 291 | end 292 | 293 | false 294 | end 295 | 296 | # Sends data to a shift register 297 | # 298 | # @param latch_pin should be a symbol representing the header pin, i.e. :P9_12 299 | # @param clock_pin should be a symbol representing the header pin, i.e. :P9_13 300 | # @param data_pin should be a symbol representing the header pin, i.e. :P9_14 301 | # @param data Integer value to write to the shift register 302 | # @param lsb optional, send least significant bit first if set 303 | # 304 | # @example 305 | # GPIO.shift_out(:P9_11, :P9_12, :P9_13, 255) 306 | def shift_out(latch_pin, clock_pin, data_pin, data, lsb=nil) 307 | raise ArgumentError, "data must be > 0 (#{data})" if data < 0 308 | digital_write(latch_pin, :LOW) 309 | 310 | binary = data.to_s(2) 311 | pad = 8 - ( binary.size % 8 ) 312 | binary = ( '0' * pad ) + binary if pad.between?(1,7) 313 | 314 | binary.reverse! if lsb 315 | 316 | binary.each_char do |bit| 317 | digital_write(clock_pin, :LOW) 318 | digital_write(data_pin, bit == '0' ? :LOW : :HIGH) 319 | digital_write(clock_pin, :HIGH) 320 | end 321 | digital_write(latch_pin, :HIGH) 322 | 323 | data 324 | end 325 | 326 | # Returns last known state from +pin+, reads state if unknown 327 | # @returns [Symbol] :HIGH or :LOW 328 | def get_gpio_state(pin) 329 | check_gpio_enabled(pin) 330 | 331 | state = Beaglebone::get_pin_status(pin, :state) 332 | return state if state 333 | 334 | digital_read(pin) 335 | end 336 | 337 | # Returns mode from +pin+, reads mode if unknown 338 | # @returns [Symbol] :IN or :OUT 339 | def get_gpio_mode(pin) 340 | check_gpio_enabled(pin) 341 | 342 | mode = Beaglebone::get_pin_status(pin, :mode) 343 | return mode if mode 344 | 345 | read_gpio_direction(pin) 346 | end 347 | 348 | # Set GPIO mode on an initialized pin 349 | # 350 | # @param pin should be a symbol representing the header pin 351 | # @param mode should specify the mode of the pin, either :IN or :OUT 352 | # 353 | # @example 354 | # GPIO.set_gpio_mode(:P9_12, :OUT) 355 | # GPIO.set_gpio_mode(:P9_11, :IN) 356 | def set_gpio_mode(pin, mode) 357 | Beaglebone::check_valid_pin(pin, :gpio) 358 | check_valid_mode(mode) 359 | check_gpio_enabled(pin) 360 | 361 | File.open("#{gpio_directory(pin)}/direction", 'w') { |f| f.write mode.to_s.downcase } 362 | Beaglebone::set_pin_status(pin, :mode, mode) 363 | end 364 | 365 | # Set GPIO edge trigger type on an initialized pin 366 | # 367 | # @param pin should be a symbol representing the header pin 368 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 369 | # @param force is optional, if set will set the mode even if already set 370 | # 371 | # @example 372 | # GPIO.set_gpio_edge(:P9_11, :RISING) 373 | def set_gpio_edge(pin, edge, force=nil) 374 | check_valid_edge(edge) 375 | Beaglebone::check_valid_pin(pin, :gpio) 376 | 377 | raise StandardError, "PIN not in GPIO IN mode: #{pin}" unless get_gpio_mode(pin) == :IN 378 | 379 | return if get_gpio_edge(pin) == edge && !force 380 | 381 | File.open("#{gpio_directory(pin)}/edge", 'w') { |f| f.write edge.to_s.downcase } 382 | testedge = read_gpio_edge(pin) 383 | if testedge != edge.to_s.downcase 384 | Beaglebone::delete_pin_status(pin, :trigger) 385 | raise StandardError, "GPIO was unable to set edge: #{pin.to_s} to #{edge.to_s}" 386 | end 387 | 388 | if edge.to_sym == :NONE 389 | Beaglebone::delete_pin_status(pin, :trigger) 390 | else 391 | Beaglebone::set_pin_status(pin, :trigger, edge.to_sym) 392 | end 393 | 394 | end 395 | 396 | # Returns the GPIO edge trigger type on an initialized pin 397 | # @return [Symbol] :NONE, :RISING, :FALLING, or :BOTH 398 | def get_gpio_edge(pin) 399 | check_gpio_enabled(pin) 400 | 401 | edge = Beaglebone::get_pin_status(pin, :trigger) 402 | return edge if edge 403 | 404 | read_gpio_edge(pin) 405 | end 406 | 407 | # Return an array of GPIO pins in use 408 | # 409 | # @return [Array] 410 | # 411 | # @example 412 | # GPIO.get_gpio_pins => [:P9_12, :P9_13] 413 | def get_gpio_pins 414 | Beaglebone.pinstatus.clone.select { |x,y| x if y[:type] == :gpio && !PINS[x][:led] }.keys 415 | end 416 | 417 | # Disable a GPIO pin 418 | # 419 | # @param pin should be a symbol representing the header pin 420 | def disable_gpio_pin(pin) 421 | 422 | Beaglebone::check_valid_pin(pin, :gpio) 423 | 424 | pininfo = PINS[pin] 425 | 426 | close_value_fd(pin) 427 | 428 | #close any running threads 429 | stop_edge_wait(pin) 430 | 431 | #write to unexport to disable gpio 432 | begin 433 | File.open('/sys/class/gpio/unexport', 'w') { |f| f.write(pininfo[:gpio]) } 434 | rescue 435 | # 436 | end 437 | 438 | #unload device tree 439 | Beaglebone::device_tree_unload("#{TREES[:GPIO][:pin]}#{pin}_.*") unless pininfo[:led] 440 | 441 | #remove status from hash so following enabled? call checks actual system 442 | Beaglebone::delete_pin_status(pin) 443 | 444 | #check to see if pin is GPIO enabled in /sys/class/gpio/ 445 | raise StandardError, "GPIO was unable to uninitalize pin: #{pin.to_s}" if enabled?(pin) 446 | 447 | end 448 | 449 | private 450 | 451 | #ensure edge type is valid 452 | def check_valid_edge(edge) 453 | raise ArgumentError, "No such edge: #{edge.to_s}" unless EDGES.include?(edge) 454 | end 455 | 456 | #read gpio edge file 457 | def read_gpio_edge(pin) 458 | check_gpio_enabled(pin) 459 | File.open("#{gpio_directory(pin)}/edge", 'r').read.to_s.strip 460 | end 461 | 462 | #check if pin is valid to use as gpio pin 463 | def valid?(pin) 464 | #check to see if pin exists 465 | return false unless PINS[pin] 466 | return false unless PINS[pin][:gpio] 467 | 468 | true 469 | end 470 | 471 | #set edge trigger to none 472 | def cleanup_edge_trigger(pin) 473 | if Beaglebone::get_pin_status(pin, :thread) == Thread.current 474 | set_gpio_edge(pin, :NONE) 475 | Beaglebone::delete_pin_status(pin, :thread) 476 | end 477 | end 478 | 479 | #convenience method for getting gpio dir in /sys 480 | def gpio_directory(pin) 481 | raise StandardError, 'Invalid Pin' unless valid?(pin) 482 | #led's are in a special place 483 | if PINS[pin][:led] 484 | "/sys/class/leds/beaglebone:green:#{pin.to_s.downcase}" 485 | else 486 | #normal gpio pins 487 | "/sys/class/gpio/gpio#{PINS[pin][:gpio]}" 488 | end 489 | end 490 | 491 | #read gpio direction file 492 | def read_gpio_direction(pin) 493 | check_gpio_enabled(pin) 494 | 495 | Beaglebone::set_pin_status(pin, :mode, File.open("#{gpio_directory(pin)}/direction", 'r').read.to_s.strip.to_sym.upcase) 496 | end 497 | 498 | #return the open value fd, or open if needed 499 | def get_value_fd(pin) 500 | check_gpio_enabled(pin) 501 | 502 | fd = Beaglebone::get_pin_status(pin, :fd_value) 503 | return fd if fd 504 | 505 | pininfo = PINS[pin] 506 | 507 | #leds aren't normal gpio pins, we can toggle them on and off however. 508 | if pininfo[:led] 509 | fd = File.open("#{gpio_directory(pin)}/brightness", 'w+') 510 | else 511 | fd = File.open("#{gpio_directory(pin)}/value", 'w+') 512 | end 513 | 514 | Beaglebone::set_pin_status(pin, :fd_value, fd) 515 | end 516 | 517 | #close value fd if open 518 | def close_value_fd(pin) 519 | fd = Beaglebone::get_pin_status(pin, :fd_value) 520 | fd.close if fd 521 | Beaglebone::delete_pin_status(pin, :fd_value) 522 | end 523 | 524 | #ensure state is valid 525 | def check_valid_state(state) 526 | #check to see if mode is valid 527 | state = state.to_sym 528 | raise ArgumentError, "No such state: #{state.to_s}" unless STATES.include?(state) 529 | end 530 | 531 | #ensure mode is valid 532 | def check_valid_mode(mode) 533 | #check to see if mode is valid 534 | mode = mode.to_sym 535 | raise ArgumentError, "No such mode: #{mode.to_s}" unless MODES.include?(mode) 536 | end 537 | 538 | #ensure gpio pin is enabled 539 | def check_gpio_enabled(pin) 540 | Beaglebone::check_valid_pin(pin, :gpio) 541 | raise StandardError, "PIN not GPIO enabled: #{pin}" unless enabled?(pin) 542 | end 543 | 544 | def create_device_tree(pin, mode, pullmode, slewrate, force = false) 545 | #get info from PINS hash 546 | pininfo = PINS[pin] 547 | 548 | #generate data value for dts 549 | #Bit 15 PIN USAGE is an indicator and should be a 1 if the pin is used or 0 if it is unused. 550 | # Bits 14-7 RESERVED is not to be used and left as 0. 551 | # Bit 6 SLEW CONTROL 0=Fast 1=Slow 552 | # Bit 5 RX Enabled 0=Disabled 1=Enabled 553 | # Bit 4 PU/PD 0=Pulldown 1=Pullup. 554 | # Bit 3 PULLUP/DN 0=Pullup/pulldown enabled 1= Pullup/pulldown disabled 555 | # Bit 2-0 MUX MODE SELECT Mode 0-7. (refer to TRM) 556 | pin_data = 0 557 | pin_data |= 0b1000000 if slewrate == :SLOW 558 | pin_data |= 0b100000 if mode == :IN 559 | case pullmode 560 | when :PULLUP 561 | pin_data |= 0b10000 562 | when :NONE 563 | pin_data |= 0b1000 564 | else 565 | # default is pulldown enabled 566 | end 567 | #set mux mode, 7 is gpio 568 | pin_data |= 7 569 | 570 | dts = GPIOTEMPLATE.clone 571 | 572 | dts.gsub!('!PIN_KEY!', pin.to_s) 573 | dts.gsub!('!PIN_DOT_KEY!', pin.to_s.gsub('_', '.')) 574 | dts.gsub!('!PIN_FUNCTION!', pininfo[:gpiofunc]) 575 | dts.gsub!('!PIN_OFFSET!', pininfo[:muxoffset]) 576 | dts.gsub!('!DATA!', "0x#{pin_data.to_s(16)}") 577 | 578 | filename = "/lib/firmware/#{TREES[:GPIO][:pin]}#{pin}_0x#{pin_data.to_s(16)}-00A0" 579 | dts_fn = "#{filename}.dts" 580 | dtb_fn = "#{filename}.dtbo" 581 | 582 | # if we've already built this file, we don't need to do it again 583 | return pin_data if File.exists?(dtb_fn) && !force 584 | 585 | dts_file = File.open(dts_fn, 'w') 586 | dts_file.write(dts) 587 | dts_file.close 588 | 589 | system("dtc -O dtb -o #{dtb_fn} -b 0 -@ #{dts_fn}") 590 | 591 | pin_data 592 | end 593 | end 594 | end 595 | 596 | # Object Oriented GPIO Implementation. 597 | # This treats the pin as an object. 598 | class GPIOPin 599 | 600 | # Initialize a GPIO pin 601 | # Return's a GPIOPin object, setting the pin mode on initialization 602 | # 603 | # @param mode should specify the mode of the pin, either :IN or :OUT 604 | # @param pullmode (optional) should specify the pull mode, :PULLUP, :PULLDOWN, or :NONE 605 | # @param slewrate (optional) should specify the slew rate, :FAST or :SLOW 606 | # 607 | # @return [GPIOPin] 608 | # 609 | # @example 610 | # p9_12 = GPIOPin.new(:P9_12, :OUT) 611 | # p9_11 = GPIOPin.new(:P9_11, :IN) 612 | def initialize(pin, mode, pullmode = nil, slewrate = nil) 613 | @pin = pin 614 | 615 | GPIO::pin_mode(@pin, mode, pullmode, slewrate) 616 | end 617 | 618 | # Sets a pin's output state 619 | # 620 | # @param state should be a symbol representin the state, :HIGH or :LOW 621 | # 622 | # @example 623 | # p9_12 = GPIOPin.new(:P9_12, :OUT) 624 | # p9_12.digital_write(:HIGH) 625 | # p9_12.digital_write(:LOW) 626 | def digital_write(state) 627 | GPIO::digital_write(@pin, state) 628 | end 629 | 630 | # Reads a pin's input state and return that value 631 | # 632 | # @return [Symbol] :HIGH or :LOW 633 | # 634 | # @example 635 | # p9_11 = GPIOPin.new(:P9_12, :OUT) 636 | # p9_11.digital_read => :HIGH 637 | def digital_read 638 | GPIO::digital_read(@pin) 639 | end 640 | 641 | # Runs a callback on an edge trigger event. 642 | # This creates a new thread that runs in the background 643 | # 644 | # @param callback A method to call when the edge trigger is detected. This method should take 3 arguments, the pin, the edge, and the counter 645 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 646 | # @param timeout is optional and specifies a time window to wait 647 | # @param repeats is optional and specifies the number of times the callback will be run 648 | # 649 | # @example 650 | # p9_11 = GPIOPin.new(:P9_11, :IN) 651 | # p9_11.run_on_edge(lambda { |pin,edge,count| puts "[#{count}] #{pin} -- #{edge}" }, :P9_11, :RISING) def run_on_edge(callback, edge, timeout=nil, repeats=nil) 652 | def run_on_edge(callback, edge, timeout=nil, repeats=nil) 653 | GPIO::run_on_edge(callback, @pin, edge, timeout, repeats) 654 | end 655 | 656 | # Runs a callback one time on an edge trigger event. 657 | # this is a convenience method for run_on_edge 658 | # @see #run_on_edge 659 | def run_once_on_edge(callback, edge, timeout=nil) 660 | GPIO::run_once_on_edge(callback, @pin, edge, timeout) 661 | end 662 | 663 | # Stops any threads waiting for data on this pin 664 | # 665 | def stop_edge_wait 666 | GPIO::stop_edge_wait(@pin) 667 | end 668 | 669 | # Wait for an edge trigger. 670 | # Returns the type that triggered the event, e.g. :RISING, :FALLING, :BOTH 671 | # 672 | # @return [Symbol] :RISING, :FALLING, or :BOTH 673 | # 674 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 675 | # @param timeout is optional and specifies a time window to wait 676 | # 677 | # @example 678 | # p9_11 = GPIOPin.new(:P9_11, :IN) 679 | # p9_11.wait_for_edge(:RISING, 30) => :RISING 680 | def wait_for_edge(edge, timeout=nil) 681 | GPIO::wait_for_edge(@pin, edge, timeout) 682 | end 683 | 684 | # Returns last known state from +pin+, reads state if unknown 685 | # @return [Symbol] :HIGH or :LOW 686 | def get_gpio_state 687 | GPIO::get_gpio_state(@pin) 688 | end 689 | 690 | # Returns mode from pin, reads mode if unknown 691 | # @return [Symbol] :IN or :OUT 692 | def get_gpio_mode 693 | GPIO::get_gpio_mode(@pin) 694 | end 695 | 696 | # Returns the GPIO edge trigger type 697 | # @return [Symbol] :NONE, :RISING, :FALLING, or :BOTH 698 | def get_gpio_edge 699 | GPIO::get_gpio_edge(@pin) 700 | end 701 | 702 | 703 | # Set GPIO mode on an initialized pin 704 | # 705 | # @param mode should specify the mode of the pin, either :IN or :OUT 706 | # 707 | # @example 708 | # p9_12.set_gpio_mode(:OUT) 709 | # p9_11.set_gpio_mode(:IN) 710 | def set_gpio_mode(mode) 711 | GPIO::set_gpio_mode(@pin, mode) 712 | end 713 | 714 | # Set GPIO edge trigger type 715 | # 716 | # @param edge should be a symbol representing the trigger type, e.g. :RISING, :FALLING, :BOTH 717 | # @param force is optional, if set will set the mode even if already set 718 | # 719 | # @example 720 | # p9_11.set_gpio_edge(:RISING) 721 | def set_gpio_edge(edge, force=nil) 722 | GPIO::set_gpio_edge(@pin, edge, force) 723 | end 724 | 725 | # Disable GPIO pin 726 | def disable_gpio_pin 727 | GPIO::disable_gpio_pin(@pin) 728 | end 729 | 730 | end 731 | end 732 | -------------------------------------------------------------------------------- /lib/beaglebone/i2c.rb: -------------------------------------------------------------------------------- 1 | # == i2c.rb 2 | # This file contains I2C methods 3 | module Beaglebone #:nodoc: 4 | # == I2C 5 | # Procedural methods for I2C control 6 | # == Summary 7 | # #setup is called to initialize an I2C device 8 | module I2C 9 | 10 | I2C_SLAVE = 0x0703 11 | 12 | @i2cstatus = {} 13 | @i2cmutex = Mutex.new 14 | 15 | class << self 16 | attr_accessor :i2cstatus, :i2cmutex 17 | 18 | # Initialize an I2C device 19 | # 20 | # @param i2c should be a symbol representing the I2C device 21 | # 22 | # @example 23 | # I2C.setup(:I2C2) 24 | def setup(i2c) 25 | check_i2c_valid(i2c) 26 | 27 | #make sure i2c not already enabled 28 | return if get_i2c_status(i2c) 29 | 30 | i2cinfo = I2CS[i2c] 31 | 32 | #ensure dtb is loaded 33 | Beaglebone::device_tree_load("#{i2cinfo[:devicetree]}") if i2cinfo[:devicetree] 34 | 35 | #open the i2c device 36 | i2c_fd = File.open(i2cinfo[:dev], 'r+') 37 | 38 | Beaglebone::set_pin_status(i2cinfo[:scl], :i2c, i2cinfo[:id]) 39 | Beaglebone::set_pin_status(i2cinfo[:scl], :type, :i2c) 40 | Beaglebone::set_pin_status(i2cinfo[:scl], :fd_i2c, i2c_fd) 41 | 42 | Beaglebone::set_pin_status(i2cinfo[:sda], :i2c, i2cinfo[:id]) 43 | Beaglebone::set_pin_status(i2cinfo[:sda], :type, :i2c) 44 | Beaglebone::set_pin_status(i2cinfo[:sda], :fd_i2c, i2c_fd) 45 | 46 | set_i2c_status(i2c, :fd_i2c, i2c_fd) 47 | set_i2c_status(i2c, :mutex, Mutex.new) 48 | end 49 | 50 | # Write data to an I2C device 51 | # 52 | # @param i2c should be a symbol representing the I2C device 53 | # @param address the address of the slave device 54 | # @param data the data to write 55 | # 56 | # @return Integer the number of bytes written 57 | # 58 | # @example 59 | # I2C.write(:I2C2, 0x1e, [0x00, 0b10010000].pack("C*") ) 60 | def write(i2c, address, data) 61 | check_i2c_enabled(i2c) 62 | 63 | lock_i2c(i2c) do 64 | i2c_fd = get_i2c_status(i2c, :fd_i2c) 65 | 66 | #set the slave address to communicate with 67 | i2c_fd.ioctl(I2C_SLAVE, address) 68 | 69 | i2c_fd.syswrite(data) 70 | end 71 | end 72 | 73 | # Read data from an I2C device 74 | # 75 | # @param i2c should be a symbol representing the I2C device 76 | # @param address the address of the slave device 77 | # @param bytes bytes to read 78 | # @param register optional register to read from 79 | # 80 | # @example 81 | # # read 3 big endian signed shorts starting at register 0x03 82 | # data = I2C.read(:I2C2, 0x1e, 6, [0x03].pack("C*")) 83 | # x,z,y = raw.unpack("s>*") 84 | def read(i2c, address, bytes=1, register=nil) 85 | check_i2c_enabled(i2c) 86 | 87 | data = '' 88 | lock_i2c(i2c) do 89 | i2c_fd = get_i2c_status(i2c, :fd_i2c) 90 | 91 | #set the slave address to communicate with 92 | i2c_fd.ioctl(I2C_SLAVE, address) 93 | 94 | i2c_fd.syswrite(register) if register 95 | 96 | data = i2c_fd.sysread(bytes) 97 | end 98 | 99 | data 100 | end 101 | 102 | # Return the file descriptor to the open I2C device 103 | # 104 | # @param i2c should be a symbol representing the I2C device 105 | def file(i2c) 106 | check_i2c_enabled(i2c) 107 | get_i2c_status(i2c, :fd_i2c) 108 | end 109 | 110 | # Disable the specified I2C device. 111 | # 112 | # @note device trees cannot be unloaded at this time without kernel panic. 113 | # 114 | # @param i2c should be a symbol representing the I2C device 115 | def disable(i2c) 116 | check_i2c_valid(i2c) 117 | check_i2c_enabled(i2c) 118 | 119 | disable_i2c_pin(I2CS[i2c][:sda]) if I2CS[i2c][:sda] 120 | disable_i2c_pin(I2CS[i2c][:scl]) if I2CS[i2c][:scl] 121 | 122 | delete_i2c_status(i2c) 123 | 124 | #removing i2c tree causes a crash... can't really disable. 125 | #Beaglebone::device_tree_unload("#{I2CS[i2c][:devicetree]}") if I2CS[i2c][:devicetree] 126 | 127 | end 128 | 129 | # Disable all active I2C interfaces 130 | def cleanup 131 | #reset all i2cs we've used and unload the device tree 132 | i2cstatus.clone.keys.each { |i2c| disable(i2c)} 133 | end 134 | 135 | private 136 | 137 | # disable i2c pin 138 | def disable_i2c_pin(pin) 139 | Beaglebone::check_valid_pin(pin, :i2c) 140 | 141 | Beaglebone::delete_pin_status(pin) 142 | end 143 | 144 | # ensure valid i2c device 145 | def check_i2c_valid(i2c) 146 | raise ArgumentError, "Invalid i2c Specified #{i2c.to_s}" unless I2CS[i2c] && I2CS[i2c][:sda] 147 | i2cinfo = I2CS[i2c.to_sym] 148 | 149 | unless i2cinfo[:scl] && [nil,:i2c].include?(Beaglebone::get_pin_status(i2cinfo[:scl], :type)) 150 | raise StandardError, "SCL Pin for #{i2c.to_s} in use" 151 | end 152 | 153 | unless i2cinfo[:sda] && [nil,:i2c].include?(Beaglebone::get_pin_status(i2cinfo[:sda], :type)) 154 | raise StandardError, "SDA Pin for #{i2c.to_s} in use" 155 | end 156 | 157 | end 158 | 159 | # ensure i2c device is enabled 160 | def check_i2c_enabled(i2c) 161 | raise ArgumentError, "i2c not enabled #{i2c.to_s}" unless get_i2c_status(i2c) 162 | end 163 | 164 | # lock i2c device 165 | def lock_i2c(i2c) 166 | check_i2c_enabled(i2c) 167 | mutex = get_i2c_status(i2c, :mutex) 168 | 169 | mutex.synchronize do 170 | yield 171 | end 172 | end 173 | 174 | # i2c hash getter 175 | def get_i2c_status(i2c, key = nil) 176 | i2cmutex.synchronize do 177 | if key 178 | i2cstatus[i2c] ? i2cstatus[i2c][key] : nil 179 | else 180 | i2cstatus[i2c] 181 | end 182 | end 183 | end 184 | 185 | # i2c hash setter 186 | def set_i2c_status(i2c, key, value) 187 | i2cmutex.synchronize do 188 | i2cstatus[i2c] ||= {} 189 | i2cstatus[i2c][key] = value 190 | end 191 | end 192 | 193 | # i2c hash delete 194 | def delete_i2c_status(i2c, key = nil) 195 | i2cmutex.synchronize do 196 | if key.nil? 197 | i2cstatus.delete(i2c) 198 | else 199 | i2cstatus[i2c].delete(key) if i2cstatus[i2c] 200 | end 201 | end 202 | end 203 | 204 | end 205 | end 206 | 207 | # Object Oriented I2C Implementation. 208 | # This treats the I2C device as an object. 209 | class I2CDevice 210 | # Initialize an I2C device. Returns an I2CDevice object 211 | # 212 | # @param i2c should be a symbol representing the I2C device 213 | # 214 | # @example 215 | # i2c = I2CDevice.new(:I2C2) 216 | def initialize(i2c) 217 | @i2c = i2c 218 | I2C::setup(@i2c) 219 | end 220 | 221 | # Write data to an I2C device 222 | # 223 | # @param address the address of the slave device 224 | # @param data the data to write 225 | # 226 | # @return Integer the number of bytes written 227 | # 228 | # @example 229 | # i2c.write(0x1e, [0x00, 0b10010000].pack("C*") ) 230 | def write(address, data) 231 | I2C::write(@i2c, address, data) 232 | end 233 | 234 | # Read data from an I2C device 235 | # 236 | # @param address the address of the slave device 237 | # @param bytes bytes to read 238 | # @param register optional register to read from 239 | # 240 | # @example 241 | # # read 3 big endian signed shorts starting at register 0x03 242 | # data = i2c.read(0x1e, 6, [0x03].pack("C*")) 243 | # x,z,y = raw.unpack("s>*") 244 | def read(address, bytes=1, register=nil) 245 | I2C::read(@i2c, address, bytes, register) 246 | end 247 | 248 | # Disable the specified I2C device. 249 | # 250 | # @note device trees cannot be unloaded at this time without kernel panic. 251 | def disable 252 | I2C::disable(@i2c) 253 | end 254 | 255 | # Return the file descriptor to the open I2C device 256 | def file 257 | I2C::file(@i2c) 258 | end 259 | end 260 | end 261 | -------------------------------------------------------------------------------- /lib/beaglebone/pwm.rb: -------------------------------------------------------------------------------- 1 | # == pwm.rb 2 | # This file contains the PWM control methods 3 | module Beaglebone #:nodoc: 4 | # == PWM 5 | # procedural methods for PWM control 6 | # == Summary 7 | # #start is called to enable a PWM pin 8 | module PWM 9 | 10 | # Polarity hash 11 | POLARITIES = { :NORMAL => 0, :INVERTED => 1 } 12 | 13 | class << self 14 | 15 | # Initialize a PWM pin 16 | # 17 | # @param pin should be a symbol representing the header pin 18 | # @param duty should specify the duty cycle 19 | # @param frequency should specify cycles per second 20 | # @param polarity optional, should specify the polarity, :NORMAL or :INVERTED 21 | # @param run optional, if false, pin will be configured but will not run 22 | # 23 | # @example 24 | # PWM.start(:P9_14, 90, 10, :NORMAL) 25 | def start(pin, duty=nil, frequency=nil, polarity=nil, run=true) 26 | #make sure the pwm controller dtb is loaded 27 | Beaglebone::device_tree_load(TREES[:PWM][:global]) 28 | 29 | Beaglebone::check_valid_pin(pin, :pwm) 30 | 31 | #if pin is enabled for something else, disable it 32 | if Beaglebone::get_pin_status(pin) && Beaglebone::get_pin_status(pin, :type) != :pwm 33 | Beaglebone::disable_pin(pin) 34 | end 35 | 36 | #load device tree for pin if not already loaded 37 | unless Beaglebone::get_pin_status(pin, :type) == :pwm 38 | Beaglebone::device_tree_load("#{TREES[:PWM][:pin]}#{pin}", 0.5) 39 | Beaglebone::set_pin_status(pin, :type, :pwm) 40 | end 41 | 42 | duty_fd = File.open("#{pwm_directory(pin)}/duty", 'r+') 43 | period_fd = File.open("#{pwm_directory(pin)}/period", 'r+') 44 | polarity_fd = File.open("#{pwm_directory(pin)}/polarity", 'r+') 45 | run_fd = File.open("#{pwm_directory(pin)}/run", 'r+') 46 | 47 | Beaglebone::set_pin_status(pin, :fd_duty, duty_fd) 48 | Beaglebone::set_pin_status(pin, :fd_period, period_fd) 49 | Beaglebone::set_pin_status(pin, :fd_polarity, polarity_fd) 50 | Beaglebone::set_pin_status(pin, :fd_run, run_fd) 51 | 52 | read_period_value(pin) 53 | read_duty_value(pin) 54 | read_polarity_value(pin) 55 | 56 | run_fd.write('0') 57 | run_fd.flush 58 | 59 | set_polarity(pin, polarity) if polarity 60 | set_frequency(pin, frequency) if frequency 61 | set_duty_cycle(pin, duty) if duty 62 | 63 | if run 64 | run_fd.write('1') 65 | run_fd.flush 66 | end 67 | 68 | raise StandardError, "Could not start PWM: #{pin}" unless read_run_value(pin) == 1 69 | true 70 | end 71 | 72 | # Returns true if specified pin is enabled in PWM mode, else false 73 | def enabled?(pin) 74 | return true if Beaglebone::get_pin_status(pin, :type) == :pwm 75 | 76 | return false unless valid?(pin) 77 | if Dir.exists?(pwm_directory(pin)) 78 | 79 | start(pin, nil, nil, nil, false) 80 | return true 81 | end 82 | false 83 | end 84 | 85 | # Stop PWM output on specified pin 86 | # 87 | # @param pin should be a symbol representing the header pin 88 | def stop(pin) 89 | Beaglebone::check_valid_pin(pin, :pwm) 90 | 91 | return false unless enabled?(pin) 92 | 93 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless Beaglebone::get_pin_status(pin, :type) == :pwm 94 | 95 | run_fd = Beaglebone::get_pin_status(pin, :fd_run) 96 | 97 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless run_fd 98 | 99 | run_fd.write('0') 100 | run_fd.flush 101 | 102 | raise StandardError, "Could not stop PWM: #{pin}" unless read_run_value(pin) == 0 103 | true 104 | end 105 | 106 | # Start PWM output on specified pin. Pin must have been previously started 107 | # 108 | # @param pin should be a symbol representing the header pin 109 | def run(pin) 110 | Beaglebone::check_valid_pin(pin, :pwm) 111 | 112 | return false unless enabled?(pin) 113 | 114 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless Beaglebone::get_pin_status(pin, :type) == :pwm 115 | 116 | run_fd = Beaglebone::get_pin_status(pin, :fd_run) 117 | 118 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless run_fd 119 | 120 | run_fd.write('1') 121 | run_fd.flush 122 | 123 | raise StandardError, "Could not start PWM: #{pin}" unless read_run_value(pin) == 1 124 | true 125 | 126 | end 127 | 128 | # Set polarity on specified pin 129 | # 130 | # @param pin should be a symbol representing the header pin 131 | # @param polarity should specify the polarity, :NORMAL or :INVERTED 132 | # @example 133 | # PWM.set_polarity(:P9_14, :INVERTED) 134 | def set_polarity(pin, polarity) 135 | check_valid_polarity(polarity) 136 | check_pwm_enabled(pin) 137 | 138 | polarity_fd = Beaglebone::get_pin_status(pin, :fd_polarity) 139 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless polarity_fd 140 | 141 | polarity_fd.write(POLARITIES[polarity.to_sym].to_s) 142 | polarity_fd.flush 143 | 144 | raise StandardError, "Could not set polarity: #{pin}" unless read_polarity_value(pin) == POLARITIES[polarity.to_sym] 145 | 146 | end 147 | 148 | # Set duty cycle of specified pin in percentage 149 | # 150 | # @param pin should be a symbol representing the header pin 151 | # @param duty should specify the duty cycle in percentage 152 | # @example 153 | # PWM.set_duty_cycle(:P9_14, 25) 154 | def set_duty_cycle(pin, duty, newperiod=nil) 155 | 156 | raise ArgumentError, "Duty cycle must be >= 0 and <= 100, #{duty} invalid" if duty < 0 || duty > 100 157 | check_pwm_enabled(pin) 158 | 159 | 160 | fd = Beaglebone::get_pin_status(pin, :fd_duty) 161 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 162 | 163 | period = newperiod || Beaglebone::get_pin_status(pin, :period) 164 | 165 | value = ((duty * period) / 100.0).round 166 | 167 | fd.write(value.to_s) 168 | fd.flush 169 | 170 | raise StandardError, "Could not set duty cycle: #{pin} (#{value})" unless read_duty_value(pin) == value 171 | 172 | Beaglebone::set_pin_status(pin, :duty_pct, duty) 173 | value 174 | 175 | end 176 | 177 | 178 | # Set duty cycle of specified pin in nanoseconds 179 | # 180 | # @param pin should be a symbol representing the header pin 181 | # @param duty should specify the duty cycle in nanoseconds 182 | # @example 183 | # PWM.set_duty_cycle_ns(:P9_14, 2500000) 184 | def set_duty_cycle_ns(pin, duty) 185 | 186 | check_pwm_enabled(pin) 187 | 188 | fd = Beaglebone::get_pin_status(pin, :fd_duty) 189 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 190 | 191 | period = Beaglebone::get_pin_status(pin, :period) 192 | 193 | duty = duty.to_i 194 | 195 | if duty < 0 || duty > period 196 | raise ArgumentError, "Duty cycle ns must be >= 0 and <= #{period} (current period), #{duty} invalid" 197 | end 198 | 199 | value = duty 200 | 201 | fd.write(value.to_s) 202 | fd.flush 203 | 204 | #since we're setting the duty_ns, we want to update the duty_pct value as well here. 205 | raise StandardError, "Could not set duty cycle: #{pin} (#{value})" unless read_duty_value(pin, true) == value 206 | 207 | value 208 | end 209 | 210 | # Set frequency of specified pin in cycles per second 211 | # 212 | # @param pin should be a symbol representing the header pin 213 | # @param frequency should specify the frequency in cycles per second 214 | # @example 215 | # PWM.set_frequency(:P9_14, 100) 216 | def set_frequency(pin, frequency) 217 | frequency = frequency.to_i 218 | raise ArgumentError, "Frequency must be > 0 and <= 1000000000, #{frequency} invalid" if frequency < 1 || frequency > 1000000000 219 | check_pwm_enabled(pin) 220 | 221 | fd = Beaglebone::get_pin_status(pin, :fd_period) 222 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 223 | 224 | duty_ns = Beaglebone::get_pin_status(pin, :duty) 225 | duty_pct = Beaglebone::get_pin_status(pin, :duty_pct) 226 | 227 | value = (1000000000 / frequency).round 228 | 229 | #we can't set the frequency lower than the previous duty cycle 230 | #adjust if necessary 231 | if duty_ns > value 232 | set_duty_cycle(pin, Beaglebone::get_pin_status(pin, :duty_pct), value) 233 | end 234 | 235 | fd.write(value.to_s) 236 | fd.flush 237 | 238 | raise StandardError, "Could not set frequency: #{pin} (#{value})" unless read_period_value(pin) == value 239 | 240 | #adjust the duty cycle if we haven't already 241 | if duty_ns <= value 242 | set_duty_cycle(pin, duty_pct, value) 243 | end 244 | 245 | value 246 | end 247 | 248 | # Set frequency of specified pin based on period duration 249 | # 250 | # @param pin should be a symbol representing the header pin 251 | # @param period should specify the length of a cycle in nanoseconds 252 | # 253 | # @example 254 | # PWM.set_frequency_ns(:P9_14, 100000000) 255 | def set_period_ns(pin, period) 256 | period = period.to_i 257 | raise ArgumentError, "period must be > 0 and <= 1000000000, #{period} invalid" if period < 1 || period > 1000000000 258 | check_pwm_enabled(pin) 259 | 260 | fd = Beaglebone::get_pin_status(pin, :fd_period) 261 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 262 | 263 | duty_ns = Beaglebone::get_pin_status(pin, :duty) 264 | value = period.to_i 265 | 266 | #we can't set the frequency lower than the previous duty cycle 267 | #adjust if necessary 268 | if duty_ns > value 269 | set_duty_cycle(pin, Beaglebone::get_pin_status(pin, :duty_pct), value) 270 | end 271 | 272 | fd.write(value.to_s) 273 | fd.flush 274 | 275 | raise StandardError, "Could not set period: #{pin} (#{value})" unless read_period_value(pin) == value 276 | 277 | #adjust the duty cycle if we haven't already 278 | if duty_ns <= value 279 | set_duty_cycle(pin, Beaglebone::get_pin_status(pin, :duty_pct), value) 280 | end 281 | 282 | value 283 | end 284 | 285 | #reset all PWM pins we've used to IN and unexport them 286 | def cleanup 287 | get_pwm_pins.each { |x| disable_pwm_pin(x) } 288 | end 289 | 290 | # Return an array of PWM pins in use 291 | # 292 | # @return [Array] 293 | # 294 | # @example 295 | # PWM.get_pwm_pins => [:P9_13, :P9_14] 296 | def get_pwm_pins 297 | Beaglebone.pinstatus.clone.select { |x,y| x if y[:type] == :pwm}.keys 298 | end 299 | 300 | # Disable a PWM pin 301 | # 302 | # @param pin should be a symbol representing the header pin 303 | def disable_pwm_pin(pin) 304 | Beaglebone::check_valid_pin(pin, :pwm) 305 | Beaglebone::delete_pin_status(pin) if Beaglebone::device_tree_unload("#{TREES[:PWM][:pin]}#{pin}") 306 | end 307 | 308 | private 309 | 310 | #ensure pin is valid pwm pin 311 | def valid?(pin) 312 | #check to see if pin exists 313 | pin = pin.to_sym 314 | 315 | return false unless PINS[pin] 316 | return false unless PINS[pin][:pwm] 317 | 318 | true 319 | end 320 | 321 | #ensure pin is pwm enabled 322 | def check_pwm_enabled(pin) 323 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless enabled?(pin) 324 | end 325 | 326 | #read run file 327 | def read_run_value(pin) 328 | check_pwm_enabled(pin) 329 | 330 | fd = Beaglebone::get_pin_status(pin, :fd_run) 331 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 332 | 333 | fd.rewind 334 | fd.read.strip.to_i 335 | end 336 | 337 | #read polarity file 338 | def read_polarity_value(pin) 339 | check_pwm_enabled(pin) 340 | 341 | fd = Beaglebone::get_pin_status(pin, :fd_polarity) 342 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 343 | 344 | fd.rewind 345 | value = fd.read.strip.to_i 346 | 347 | Beaglebone::set_pin_status(pin, :polarity, value) 348 | 349 | end 350 | 351 | #read duty file 352 | def read_duty_value(pin, setpct=false) 353 | check_pwm_enabled(pin) 354 | 355 | fd = Beaglebone::get_pin_status(pin, :fd_duty) 356 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 357 | 358 | fd.rewind 359 | value = fd.read.strip.to_i 360 | 361 | Beaglebone::set_pin_status(pin, :duty, value) 362 | # only set duty_pct if it is unset or if we are forcing it. 363 | if setpct || Beaglebone::get_pin_status(pin, :duty_pct).nil? 364 | duty_pct = ((value * 100.0) / Beaglebone::get_pin_status(pin, :period)).round 365 | Beaglebone::set_pin_status(pin, :duty_pct, duty_pct) 366 | end 367 | 368 | value 369 | end 370 | 371 | #read period file 372 | def read_period_value(pin) 373 | check_pwm_enabled(pin) 374 | 375 | fd = Beaglebone::get_pin_status(pin, :fd_period) 376 | raise StandardError, "Pin is not PWM enabled: #{pin}" unless fd 377 | 378 | fd.rewind 379 | value = fd.read.strip.to_i 380 | 381 | Beaglebone::set_pin_status(pin, :period, value) 382 | 383 | value 384 | end 385 | 386 | #return sysfs directory for pwm control 387 | def pwm_directory(pin) 388 | raise StandardError, 'Invalid Pin' unless valid?(pin) 389 | Dir.glob("/sys/devices/ocp.*/pwm_test_#{pin}.*").first 390 | end 391 | 392 | #ensure polarity is valid 393 | def check_valid_polarity(polarity) 394 | #check to see if mode is valid 395 | polarity = polarity.to_sym 396 | raise ArgumentError, "No such polarity: #{polarity.to_s}" unless POLARITIES.include?(polarity) 397 | end 398 | 399 | end 400 | end 401 | 402 | # Object Oriented PWM Implementation. 403 | # This treats the pin as an object. 404 | class PWMPin 405 | 406 | # Initialize a PWM pin 407 | # 408 | # 409 | # @param duty should specify the duty cycle 410 | # @param frequency should specify cycles per second 411 | # @param polarity optional, should specify the polarity, :NORMAL or :INVERTED 412 | # @param run optional, if false, pin will be configured but will not run 413 | # 414 | # @example 415 | # p9_14 = PWMPin.new(:P9_14, 90, 10, :NORMAL) 416 | def initialize(pin, duty=nil, frequency=nil, polarity=nil, run=true) 417 | @pin = pin 418 | PWM::start(@pin, duty, frequency, polarity, run) 419 | end 420 | 421 | # Stop PWM output on pin 422 | def stop 423 | PWM::stop(@pin) 424 | end 425 | 426 | # Start PWM output on pin. Pin must have been previously started 427 | def run 428 | PWM::run(@pin) 429 | end 430 | 431 | # Set polarity on pin 432 | # 433 | # @param polarity should specify the polarity, :NORMAL or :INVERTED 434 | # @example 435 | # p9_14.set_polarity(:INVERTED) 436 | def set_polarity(polarity) 437 | PWM::set_polarity(@pin, polarity) 438 | end 439 | 440 | # Set duty cycle of pin in percentage 441 | # 442 | # 443 | # @param duty should specify the duty cycle in percentage 444 | # @example 445 | # p9_14.set_duty_cycle(25) 446 | def set_duty_cycle(duty, newperiod=nil) 447 | PWM::set_duty_cycle(@pin, duty, newperiod) 448 | end 449 | 450 | # Set duty cycle of pin in nanoseconds 451 | # 452 | # @param duty should specify the duty cycle in nanoseconds 453 | # @example 454 | # p9_14.set_duty_cycle_ns(2500000) 455 | def set_duty_cycle_ns(duty) 456 | PWM::set_duty_cycle_ns(@pin, duty) 457 | end 458 | 459 | # Set frequency of pin in cycles per second 460 | # 461 | # @param frequency should specify the frequency in cycles per second 462 | # @example 463 | # p9_14.set_frequency(100) 464 | def set_frequency(frequency) 465 | PWM::set_frequency(@pin, frequency) 466 | end 467 | 468 | # Set frequency of pin based on period duration 469 | # 470 | # @param period should specify the length of a cycle in nanoseconds 471 | # @example 472 | # p9_14.set_frequency_ns(100000000) 473 | def set_period_ns(period) 474 | PWM::set_period_ns(@pin, period) 475 | end 476 | 477 | # Disable PWM pin 478 | def disable_pwm_pin 479 | PWM::disable_pwm_pin(@pin) 480 | end 481 | end 482 | 483 | end 484 | -------------------------------------------------------------------------------- /lib/beaglebone/shiftregister.rb: -------------------------------------------------------------------------------- 1 | # == shiftregister.rb 2 | # This file contains the shiftregister control methods 3 | module Beaglebone #:nodoc: 4 | class ShiftRegister 5 | 6 | # Create a shiftregister object based on 3 GPIO pins 7 | # 8 | # @param latch_pin should be a symbol representing the header pin, i.e. :P9_12 9 | # @param clock_pin should be a symbol representing the header pin, i.e. :P9_13 10 | # @param data_pin should be a symbol representing the header pin, i.e. :P9_14 11 | # @param lsb optional, send least significant bit first if set 12 | # 13 | # @example 14 | # shiftregister = ShiftRegister.new(:P9_11, :P9_12, :P9_13) 15 | def initialize(latch_pin, clock_pin, data_pin, lsb=nil) 16 | 17 | @latch_pin = latch_pin 18 | @clock_pin = clock_pin 19 | @data_pin = data_pin 20 | @lsb = lsb 21 | 22 | GPIO::pin_mode(@latch_pin, :OUT) 23 | GPIO::pin_mode(@clock_pin, :OUT) 24 | GPIO::pin_mode(@data_pin, :OUT) 25 | end 26 | 27 | # Send data to shift register 28 | # 29 | # @param data Integer value to write to the shift register 30 | # @param lsb optional, send least significant bit first if set 31 | # 32 | # @example 33 | # shiftregister = ShiftRegister.new(:P9_11, :P9_12, :P9_13) 34 | # shiftregister.shift_out(255) 35 | def shift_out(data, lsb=nil) 36 | GPIO::shift_out(@latch_pin, @clock_pin, @data_pin, data, lsb || @lsb) 37 | end 38 | 39 | end 40 | end 41 | -------------------------------------------------------------------------------- /lib/beaglebone/spi.rb: -------------------------------------------------------------------------------- 1 | # == spi.rb 2 | # This file contains SPI methods 3 | module Beaglebone #:nodoc: 4 | # == SPI 5 | # Procedural methods for SPI control 6 | # == Summary 7 | # #setup is called to initialize an SPI device 8 | module SPI 9 | #some ioctl defines 10 | IOC_NONE = 0 11 | IOC_WRITE = 1 12 | IOC_READ = 2 13 | 14 | IOC_NRBITS = 8 15 | IOC_TYPEBITS = 8 16 | IOC_SIZEBITS = 14 17 | IOC_DIRBITS = 2 18 | 19 | IOC_NRSHIFT = 0 20 | IOC_TYPESHIFT = IOC_NRSHIFT+IOC_NRBITS 21 | IOC_SIZESHIFT = IOC_TYPESHIFT+IOC_TYPEBITS 22 | IOC_DIRSHIFT = IOC_SIZESHIFT+IOC_SIZEBITS 23 | 24 | #spi defines 25 | SPI_CPHA = 0x01 26 | SPI_CPOL = 0x02 27 | 28 | SPI_MODE_0 = (0|0) 29 | SPI_MODE_1 = (0|SPI_CPHA) 30 | SPI_MODE_2 = (SPI_CPOL|0) 31 | SPI_MODE_3 = (SPI_CPOL|SPI_CPHA) 32 | 33 | SPI_MODES = { 34 | :SPI_MODE_0 => SPI_MODE_0, 35 | :SPI_MODE_1 => SPI_MODE_1, 36 | :SPI_MODE_2 => SPI_MODE_2, 37 | :SPI_MODE_3 => SPI_MODE_3, 38 | } 39 | 40 | SPI_CS_HIGH = 0x04 41 | SPI_LSB_FIRST = 0x08 42 | SPI_3WIRE = 0x10 43 | SPI_LOOP = 0x20 44 | SPI_NO_CS = 0x40 45 | SPI_READY = 0x80 46 | 47 | SPI_IOC_MAGIC = 'k'.ord 48 | 49 | SPI_IOC_RD_MODE = 2147576577 #ior(SPI_IOC_MAGIC, 1, 1) 50 | SPI_IOC_WR_MODE = 1073834753 #iow(SPI_IOC_MAGIC, 1, 1) 51 | 52 | SPI_IOC_RD_LSB_FIRST = 2147576578 #ior(SPI_IOC_MAGIC, 2, 1) 53 | SPI_IOC_WR_LSB_FIRST = 1073834754 #iow(SPI_IOC_MAGIC, 2, 1) 54 | 55 | SPI_IOC_RD_BITS_PER_WORD = 2147576579 #ior(SPI_IOC_MAGIC, 3, 1) 56 | SPI_IOC_WR_BITS_PER_WORD = 1073834755 #iow(SPI_IOC_MAGIC, 3, 1) 57 | 58 | SPI_IOC_RD_MAX_SPEED_HZ = 2147773188 #ior(SPI_IOC_MAGIC, 4, 4) 59 | SPI_IOC_WR_MAX_SPEED_HZ = 1074031364 #iow(SPI_IOC_MAGIC, 4, 4) 60 | 61 | SPI_IOC_MESSAGE_1 = 1075866368 62 | 63 | SPI_IOC_TRANSFER_STRUCT_SIZE = 32 64 | 65 | @spistatus = {} 66 | @spimutex = Mutex.new 67 | 68 | class << self 69 | 70 | attr_accessor :spistatus, :spimutex 71 | 72 | # Initialize an SPI device 73 | # 74 | # @param spi should be a symbol representing the SPI device 75 | # @param mode optional, default 0, specifies the SPI mode :SPI_MODE_0 through 3 76 | # @param speed optional, specifies the SPI communication speed 77 | # @param bpw optional, specifies the bits per word 78 | # 79 | # @example 80 | # SPI.setup(:SPI0, SPI_MODE_0) 81 | def setup(spi, mode=nil, speed=1000000, bpw=8) 82 | check_spi_valid(spi) 83 | 84 | #make sure spi not already enabled 85 | return if get_spi_status(spi) 86 | 87 | mode = mode || SPI_MODE_0 88 | 89 | spiinfo = SPIS[spi] 90 | 91 | #ensure dtb is loaded 92 | Beaglebone::device_tree_load("#{spiinfo[:devicetree]}") if spiinfo[:devicetree] 93 | 94 | #open the spi device. 95 | spi_fd = File.open("#{spiinfo[:dev]}#{SPIS[:counter]}.0", 'r+') 96 | 97 | set_spi_status(spi, :fd_spi, spi_fd) 98 | set_spi_status(spi, :mutex, Mutex.new) 99 | 100 | set_mode(spi, mode) 101 | set_bpw(spi, bpw) 102 | set_speed(spi, speed) 103 | 104 | SPIS[:counter] += 1 105 | 106 | spiinfo[:pins].each do |pin| 107 | Beaglebone::set_pin_status(pin, :spi, spiinfo[:id]) 108 | Beaglebone::set_pin_status(pin, :type, :spi) 109 | Beaglebone::set_pin_status(pin, :fd_spi, spi_fd) 110 | end 111 | 112 | end 113 | 114 | # Transfer data to and from the SPI device 115 | # 116 | # @return String data read from SPI device 117 | # 118 | # @param spi should be a symbol representing the SPI device 119 | # @param tx_data data to transmit 120 | # @param readbytes bytes to read, otherwise it sizeof tx_data is used 121 | # @param speed optional, speed to xfer at 122 | # @param delay optional delay 123 | # @param bpw optional bits per word 124 | # 125 | # @example 126 | # # communicate with MCP3008 127 | # # byte 1: start bit 128 | # # byte 2: single(1)/diff(0),3 bites for channel, null pad 129 | # # byte 3: don't care 130 | # SPI.setup(:SPI0, SPI_MODE_0) 131 | # raw = SPI.xfer(:SPI0, [ 0b00000001, 0b10000000, 0].pack("C*")) 132 | # data = raw.unpack("C*") 133 | # val = ((data[1] & 0b00000011) << 8 ) | data[2] 134 | def xfer(spi, tx_data, readbytes=0, speed=nil, delay=nil, bpw=nil) 135 | check_spi_enabled(spi) 136 | 137 | speed = speed || get_spi_status(spi, :speed) 138 | delay = delay || 0 139 | bpw = bpw || get_spi_status(spi, :bpw) 140 | 141 | if tx_data.size > readbytes 142 | readbytes = tx_data.size 143 | end 144 | 145 | rx_data = ' ' * readbytes 146 | 147 | lock_spi(spi) do 148 | spi_fd = get_spi_status(spi, :fd_spi) 149 | 150 | ### SPI IOC transfer structure 151 | # __u64 tx_buf; 152 | # __u64 rx_buf; 153 | # 154 | # __u32 len; 155 | # __u32 speed_hz; 156 | # 157 | # __u16 delay_usecs; 158 | # __u8 bits_per_word; 159 | # __u8 cs_change; 160 | # __u32 pad; 161 | ### 162 | 163 | msg = [ tx_data, 0, 164 | rx_data, 0, 165 | readbytes, 166 | speed, 167 | delay, 168 | bpw, 169 | 0, 170 | 0].pack('pLpLLLSCCL') 171 | 172 | #ioctl call to begin data transfer 173 | spi_fd.ioctl(SPI_IOC_MESSAGE_1, msg) 174 | #speedup with defined int 175 | #spi_fd.ioctl(spi_ioc_message(1), msg) 176 | 177 | end 178 | rx_data 179 | end 180 | 181 | # Return the file descriptor to the open SPI device 182 | # 183 | # @param spi should be a symbol representing the SPI device 184 | def file(spi) 185 | check_spi_enabled(spi) 186 | get_spi_status(spi, :fd_spi) 187 | end 188 | 189 | # Set the communication speed of the specified SPI device 190 | # 191 | # @param spi should be a symbol representing the SPI device 192 | # @param speed communication speed 193 | def set_speed(spi, speed) 194 | speed = speed.to_i 195 | raise ArgumentError, "Speed (#{speed.to_s}) must be a positive integer" unless speed > 0 196 | 197 | check_spi_enabled(spi) 198 | spi_fd = get_spi_status(spi, :fd_spi) 199 | 200 | spi_fd.ioctl(SPI_IOC_WR_MAX_SPEED_HZ, [speed].pack('L')) 201 | 202 | # deal with old versions of ruby that can't handle large number IOCTL 203 | # https://bugs.ruby-lang.org/issues/6127 204 | begin 205 | spi_fd.ioctl(SPI_IOC_RD_MAX_SPEED_HZ, [speed].pack('L')) 206 | rescue 207 | puts 'Warning, old Ruby detected, cannot set SPI max read speed' 208 | end 209 | 210 | set_spi_status(spi, :speed, speed) 211 | end 212 | 213 | # Set the communication speed of the specified SPI device 214 | # 215 | # @param spi should be a symbol representing the SPI device 216 | # @param mode should be a valid SPI mode, e.g. :SPI_MODE_0 through 3 217 | def set_mode(spi, mode) 218 | check_spi_enabled(spi) 219 | 220 | #if mode is a symbol, translate it to the appropriate value 221 | mode = SPI_MODES[mode] if mode.class == Symbol && SPI_MODES[mode] 222 | 223 | raise ArgumentError, "Mode (#{mode.to_s}) is unknown" unless SPI_MODES.values.include?(mode) 224 | spi_fd = get_spi_status(spi, :fd_spi) 225 | 226 | # deal with old versions of ruby that can't handle large number IOCTL 227 | # https://bugs.ruby-lang.org/issues/6127 228 | begin 229 | spi_fd.ioctl(SPI_IOC_WR_MODE, [mode].pack('C')) 230 | spi_fd.ioctl(SPI_IOC_RD_MODE, [mode].pack('C')) 231 | rescue 232 | puts 'Warning, old Ruby detected, cannot set SPI mode' 233 | end 234 | 235 | end 236 | 237 | # Set the bits per word of the specified SPI device 238 | # 239 | # @param spi should be a symbol representing the SPI device 240 | # @param bpw should specify the bits per word 241 | def set_bpw(spi, bpw) 242 | bpw = bpw.to_i 243 | raise ArgumentError, "BPW (#{bpw.to_s}) must be a positive integer" unless bpw > 0 244 | 245 | check_spi_enabled(spi) 246 | spi_fd = get_spi_status(spi, :fd_spi) 247 | 248 | spi_fd.ioctl(SPI_IOC_WR_BITS_PER_WORD, [bpw].pack('C')) 249 | 250 | # deal with old versions of ruby that can't handle large number IOCTL 251 | # https://bugs.ruby-lang.org/issues/6127 252 | begin 253 | spi_fd.ioctl(SPI_IOC_RD_BITS_PER_WORD, [bpw].pack('C')) 254 | rescue 255 | puts 'Warning, old Ruby detected, cannot set SPI read bits per word' 256 | end 257 | 258 | set_spi_status(spi, :bpw, bpw) 259 | end 260 | 261 | # Disable the specified SPI device 262 | # 263 | # @note device trees cannot be unloaded at this time without kernel panic. 264 | # 265 | # @param spi should be a symbol representing the SPI device 266 | def disable(spi) 267 | check_spi_valid(spi) 268 | check_spi_enabled(spi) 269 | 270 | SPIS[spi][:pins].each do |pin| 271 | disable_spi_pin(pin) 272 | end 273 | 274 | delete_spi_status(spi) 275 | 276 | #removing spi tree causes a crash... can't really disable. 277 | #Beaglebone::device_tree_unload("#{SPIS[spi][:devicetree]}") if SPIS[spi][:devicetree] 278 | 279 | end 280 | 281 | # Disable all active SPI devices 282 | def cleanup 283 | #reset all spis we've used and unload the device tree 284 | spistatus.clone.keys.each { |spi| disable(spi)} 285 | end 286 | 287 | private 288 | 289 | #ensure spi is valid 290 | def check_spi_valid(spi) 291 | raise ArgumentError, "Invalid spi Specified #{spi.to_s}" unless SPIS[spi] && SPIS[spi][:sclk] 292 | spiinfo = SPIS[spi.to_sym] 293 | 294 | unless spiinfo[:sclk] && [nil,:spi].include?(Beaglebone::get_pin_status(spiinfo[:sclk], :type)) 295 | raise StandardError, "SCLK Pin for #{spi.to_s} in use" 296 | end 297 | 298 | unless spiinfo[:d0] && [nil,:spi].include?(Beaglebone::get_pin_status(spiinfo[:d0], :type)) 299 | raise StandardError, "D0 Pin for #{spi.to_s} in use" 300 | end 301 | 302 | unless spiinfo[:d1] && [nil,:spi].include?(Beaglebone::get_pin_status(spiinfo[:d1], :type)) 303 | raise StandardError, "D1 Pin for #{spi.to_s} in use" 304 | end 305 | 306 | unless spiinfo[:cs0] && [nil,:spi].include?(Beaglebone::get_pin_status(spiinfo[:cs0], :type)) 307 | raise StandardError, "CS0 Pin for #{spi.to_s} in use" 308 | end 309 | end 310 | 311 | # lock spi 312 | def lock_spi(spi) 313 | check_spi_enabled(spi) 314 | mutex = get_spi_status(spi, :mutex) 315 | 316 | mutex.synchronize do 317 | yield 318 | end 319 | end 320 | 321 | # ensure spi is enabled 322 | def check_spi_enabled(spi) 323 | raise ArgumentError, "spi not enabled #{spi.to_s}" unless get_spi_status(spi) 324 | end 325 | 326 | # disable spi pin 327 | def disable_spi_pin(pin) 328 | Beaglebone::check_valid_pin(pin, :spi) 329 | 330 | Beaglebone::delete_pin_status(pin) 331 | end 332 | 333 | #ports of ioctl definitions 334 | def ioc(dir,type,nr,size) 335 | (((dir) << IOC_DIRSHIFT) | 336 | ((type) << IOC_TYPESHIFT) | 337 | ((nr) << IOC_NRSHIFT) | 338 | ((size) << IOC_SIZESHIFT)) 339 | end 340 | 341 | def ior(type,nr,size) 342 | ioc(IOC_READ,(type),(nr),size) 343 | end 344 | 345 | def iow(type,nr,size) 346 | ioc(IOC_WRITE,(type),(nr),size) 347 | end 348 | 349 | def spi_msgsize(n) 350 | n*SPI_IOC_TRANSFER_STRUCT_SIZE < 1< 4 126 | def write(uart, data) 127 | check_uart_enabled(uart) 128 | 129 | pin_tx = UARTS[uart][:tx] 130 | 131 | Beaglebone::check_valid_pin(pin_tx, :uart) 132 | 133 | fd = Beaglebone::get_pin_status(pin_tx, :fd_uart) 134 | 135 | ret = fd.write(data) 136 | fd.flush 137 | 138 | ret 139 | end 140 | 141 | # Write a line data to a UART device. 142 | # This is a convenience method using #write 143 | # @see #write 144 | # 145 | # @param uart should be a symbol representing the UART device 146 | # @param data the data to write 147 | # 148 | # @return Integer the number of bytes written 149 | # 150 | # @example 151 | # UART.writeln(:UART1, "1234") => 5 152 | def writeln(uart, data) 153 | write(uart, data + "\n") 154 | end 155 | 156 | # Read one character from a UART device 157 | # 158 | # @param uart should be a symbol representing the UART device 159 | # 160 | # @return String the character read from the UART device 161 | # 162 | # @example 163 | # UART.readchars(:UART1) => "x" 164 | def readchar(uart) 165 | readchars(uart, 1) 166 | end 167 | 168 | # Read characters from a UART device 169 | # 170 | # @param uart should be a symbol representing the UART device 171 | # @param bytes number of bytes to read 172 | # 173 | # @return String the characters read from the UART device 174 | # 175 | # @example 176 | # UART.readchars(:UART1, 2) => "xx" 177 | def readchars(uart, bytes) 178 | check_uart_enabled(uart) 179 | ensure_read_lock(uart) 180 | 181 | buffer = '' 182 | 183 | pin_rx = UARTS[uart][:rx] 184 | 185 | Beaglebone::check_valid_pin(pin_rx, :uart) 186 | 187 | fd = Beaglebone::get_pin_status(pin_rx, :fd_uart) 188 | 189 | set_uart_status(uart, :waiting, true) 190 | 191 | while bytes > 0 do 192 | buffer << fd.readchar 193 | bytes -= 1 194 | end 195 | set_uart_status(uart, :waiting, false) 196 | 197 | buffer 198 | end 199 | 200 | # Read a line from a UART device 201 | # 202 | # @param uart should be a symbol representing the UART device 203 | # 204 | # @return String the line read from the UART device 205 | # 206 | # @example 207 | # UART.readline(:UART1) => "A line of text" 208 | def readline(uart) 209 | check_uart_enabled(uart) 210 | ensure_read_lock(uart) 211 | 212 | pin_rx = UARTS[uart][:rx] 213 | 214 | Beaglebone::check_valid_pin(pin_rx, :uart) 215 | 216 | fd = Beaglebone::get_pin_status(pin_rx, :fd_uart) 217 | 218 | set_uart_status(uart, :waiting, true) 219 | 220 | data = fd.readline.chop 221 | 222 | set_uart_status(uart, :waiting, false) 223 | 224 | data 225 | end 226 | 227 | # Read a character from a UART device and pass it to the specified block 228 | # 229 | # @param uart should be a symbol representing the UART device 230 | # 231 | # @example 232 | # UART.each_char(:UART1) { |x| puts "read: #{x}" } 233 | def each_char(uart) 234 | loop do 235 | data = readchars(uart, 1) 236 | yield data 237 | end 238 | 239 | end 240 | 241 | # Read characters from a UART device and pass them to the specified block 242 | # 243 | # @param uart should be a symbol representing the UART device 244 | # @param chars should be the number of chars to read 245 | # 246 | # @example 247 | # UART.each_chars(:UART1, 2) { |x| puts "read: #{x}" } 248 | def each_chars(uart, chars) 249 | loop do 250 | data = readchars(uart, chars) 251 | yield data 252 | end 253 | end 254 | 255 | 256 | # Read lines from a UART device and pass them to the specified block 257 | # 258 | # @param uart should be a symbol representing the UART device 259 | # 260 | # @example 261 | # UART.each_line(:UART1) { |x| puts "read: #{x}" } 262 | def each_line(uart) 263 | loop do 264 | data = readline(uart) 265 | yield data 266 | end 267 | end 268 | 269 | # Runs a callback after receiving a line of data from a UART device 270 | # This creates a new thread that runs in the background 271 | # 272 | # @param callback A method to call when the data is received. This method should take 3 arguments, the UART, the line read, and the counter 273 | # @param uart should be a symbol representing the UART device 274 | # @param repeats is optional and specifies the number of times the callback will be run 275 | # 276 | # @example 277 | # callback = lambda { |uart, line, count| puts "[#{uart}:#{count}] #{line} "} 278 | # UART.run_on_each_line(callback, :UART1) 279 | def run_on_each_line(callback, uart, repeats=nil) 280 | check_uart_enabled(uart) 281 | 282 | raise StandardError, "Already waiting for data on uart: #{uart}" if get_uart_status(uart, :waiting) 283 | raise StandardError, "Already waiting for data on uart: #{uart}" if get_uart_status(uart, :thread) 284 | 285 | thread = Thread.new(callback, uart, repeats) do |c, u, r| 286 | begin 287 | count = 0 288 | each_line(u) do |line| 289 | 290 | c.call(u, line, count) if c 291 | 292 | count += 1 293 | break if r && count >= r 294 | end 295 | rescue => ex 296 | puts ex 297 | puts ex.backtrace 298 | ensure 299 | delete_uart_status(u, :thread) 300 | set_uart_status(uart, :waiting, false) 301 | end 302 | end 303 | set_uart_status(uart, :thread, thread) 304 | end 305 | 306 | # Convenience method for run_on_each_line with repeats set to 1 307 | # @see #run_on_each_line 308 | def run_once_on_each_line(callback, uart) 309 | run_on_each_line(callback, uart, 1) 310 | end 311 | 312 | # Runs a callback after receiving data from a UART device 313 | # This creates a new thread that runs in the background 314 | # 315 | # @param callback A method to call when the data is received. This method should take 3 arguments, the UART, the line read, and the counter 316 | # @param uart should be a symbol representing the UART device 317 | # @param chars should be the number of chars to read 318 | # @param repeats is optional and specifies the number of times the callback will be run 319 | # 320 | # @example 321 | # callback = lambda { |uart, data, count| puts "[#{uart}:#{count}] #{data} "} 322 | # UART.run_on_each_chars(callback, :UART1, 2) 323 | def run_on_each_chars(callback, uart, chars=1, repeats=nil) 324 | check_uart_enabled(uart) 325 | 326 | raise StandardError, "Already waiting for data on uart: #{uart}" if get_uart_status(uart, :waiting) 327 | raise StandardError, "Already waiting for data on uart: #{uart}" if get_uart_status(uart, :thread) 328 | 329 | thread = Thread.new(callback, uart, chars, repeats) do |c, u, ch, r| 330 | begin 331 | count = 0 332 | each_chars(u, ch) do |line| 333 | 334 | c.call(u, line, count) if c 335 | 336 | count += 1 337 | break if r && count >= r 338 | end 339 | rescue => ex 340 | puts ex 341 | puts ex.backtrace 342 | ensure 343 | delete_uart_status(u, :thread) 344 | set_uart_status(uart, :waiting, false) 345 | end 346 | end 347 | set_uart_status(uart, :thread, thread) 348 | end 349 | 350 | # Convenience method for run_on_each_chars with chars and repeats set to 1 351 | # @see #run_on_each_chars 352 | def run_once_on_each_char(callback, uart) 353 | run_once_on_each_chars(callback, uart, 1) 354 | end 355 | 356 | # Convenience method for run_on_each_chars with chars and repeats set to 1 357 | # @see #run_on_each_chars 358 | def run_once_on_each_chars(callback, uart, chars=1) 359 | run_on_each_chars(callback, uart, chars, 1) 360 | end 361 | 362 | # Convenience method for run_on_each_chars with chars set to 1 363 | # @see #run_on_each_chars 364 | def run_on_each_char(callback, uart, repeats=nil) 365 | run_on_each_chars(callback, uart, 1, repeats) 366 | end 367 | 368 | # Disable a UART device. 369 | # 370 | # @note device trees cannot be unloaded at this time without kernel panic. 371 | # 372 | # @param uart should be a symbol representing the UART device 373 | # 374 | # @example 375 | # UART.disable(:UART1) 376 | def disable(uart) 377 | check_uart_valid(uart) 378 | check_uart_enabled(uart) 379 | 380 | stop_read_wait(uart) 381 | 382 | disable_uart_pin(UARTS[uart][:rx]) if UARTS[uart][:rx] 383 | disable_uart_pin(UARTS[uart][:tx]) if UARTS[uart][:tx] 384 | 385 | delete_uart_status(uart) 386 | end 387 | 388 | # Stops any threads waiting for data on the specified UART 389 | def stop_read_wait(uart) 390 | thread = get_uart_status(uart, :thread) 391 | 392 | thread.exit if thread 393 | thread.join if thread 394 | end 395 | 396 | # Disable all UART devices 397 | def cleanup 398 | #reset all UARTs we've used and unload the device tree 399 | uartstatus.clone.keys.each { |uart| disable(uart)} 400 | end 401 | 402 | private 403 | 404 | # return hash data for specified UART 405 | def get_uart_status(uart, key = nil) 406 | uartmutex.synchronize do 407 | if key 408 | uartstatus[uart] ? uartstatus[uart][key] : nil 409 | else 410 | uartstatus[uart] 411 | end 412 | end 413 | end 414 | 415 | # set hash data for specified UART 416 | def set_uart_status(uart, key, value) 417 | uartmutex.synchronize do 418 | uartstatus[uart] ||= {} 419 | uartstatus[uart][key] = value 420 | end 421 | end 422 | 423 | # remove hash data for specified UART 424 | def delete_uart_status(uart, key = nil) 425 | uartmutex.synchronize do 426 | if key.nil? 427 | uartstatus.delete(uart) 428 | else 429 | uartstatus[uart].delete(key) if uartstatus[uart] 430 | end 431 | end 432 | end 433 | 434 | # ensure UART is valid 435 | def check_uart_valid(uart) 436 | raise ArgumentError, "Invalid UART Specified #{uart.to_s}" unless UARTS[uart] 437 | uartinfo = UARTS[uart.to_sym] 438 | 439 | if uartinfo[:tx] 440 | unless [nil,:uart].include?(Beaglebone::get_pin_status(uartinfo[:tx], :type)) 441 | raise StandardError, "TX Pin for #{uart.to_s} in use" 442 | end 443 | end 444 | 445 | if uartinfo[:rx] 446 | unless [nil,:uart].include?(Beaglebone::get_pin_status(uartinfo[:rx], :type)) 447 | raise StandardError, "RX Pin for #{uart.to_s} in use" 448 | end 449 | end 450 | 451 | end 452 | 453 | # ensure UART is enabled 454 | def check_uart_enabled(uart) 455 | raise ArgumentError, "UART not enabled #{uart.to_s}" unless get_uart_status(uart) 456 | end 457 | 458 | # ensure we have a read lock for the UART 459 | def ensure_read_lock(uart) 460 | #ensure we're the only ones reading 461 | if get_uart_status(uart, :thread) && get_uart_status(uart, :thread) != Thread.current 462 | raise StandardError, "Already waiting for data on uart: #{uart}" 463 | end 464 | 465 | if get_uart_status(uart, :waiting) && get_uart_status(uart, :thread) != Thread.current 466 | raise StandardError, "Already waiting for data on uart: #{uart}" 467 | end 468 | end 469 | 470 | # check to make sure the specified speed is valid 471 | def check_speed_valid(speed) 472 | raise ArgumentError, "Invalid speed specified: #{speed}" unless SPEEDS.include?(speed) 473 | end 474 | 475 | # disable a uart pin 476 | def disable_uart_pin(pin) 477 | Beaglebone::check_valid_pin(pin, :uart) 478 | 479 | id = Beaglebone::get_pin_status(pin, :uart) 480 | 481 | Beaglebone::delete_pin_status(pin) 482 | 483 | #removing uart tree causes a crash... can't really disable. 484 | return if true 485 | 486 | Beaglebone::device_tree_unload("#{TREES[:UART][:pin]}#{id}") 487 | 488 | end 489 | 490 | def create_device_tree(uart, force = false) 491 | uartinfo = UARTS[uart] 492 | 493 | #ensure valid uart, and a template to create this exists 494 | return unless uartinfo 495 | 496 | uartnum = uartinfo[:id] 497 | 498 | return unless uartnum && UARTTEMPLATE[uartnum] 499 | 500 | dts = UARTTEMPLATE[uartinfo[:id]].clone 501 | 502 | filename = "/lib/firmware/#{TREES[:UART][:pin]}#{uartnum}-00A0" 503 | dts_fn = "#{filename}.dts" 504 | dtb_fn = "#{filename}.dtbo" 505 | 506 | # if we've already built this file, we don't need to do it again 507 | return if File.exists?(dtb_fn) && !force 508 | 509 | dts_file = File.open(dts_fn, 'w') 510 | dts_file.write(dts) 511 | dts_file.close 512 | 513 | system("dtc -O dtb -o #{dtb_fn} -b 0 -@ #{dts_fn}") 514 | 515 | end 516 | 517 | end 518 | end 519 | 520 | # Object Oriented UART Implementation. 521 | # This treats the UART device as an object. 522 | class UARTDevice 523 | # Initialize a UART device. Returns a UARTDevice object 524 | # 525 | # @param uart should be a symbol representing the UART device 526 | # @param speed should be an integer thats a valid speed. @see SPEEDS 527 | # 528 | # @example 529 | # uart1 = UARTDevice.new(:UART1, 9600) 530 | def initialize(uart, speed=9600) 531 | @uart = uart 532 | UART::setup(@uart, speed) 533 | end 534 | 535 | # Set the speed of the UART 536 | # 537 | # @param speed should be an integer thats a valid speed. @see SPEEDS 538 | # 539 | # @example 540 | # uart1.set_speed(9600) 541 | def set_speed(speed) 542 | UART::set_speed(@uart, speed) 543 | end 544 | 545 | # Write data to a UART device 546 | # 547 | # @param data the data to write 548 | # 549 | # @return Integer the number of bytes written 550 | # 551 | # @example 552 | # uart1.write("1234") => 4 553 | def write(data) 554 | UART::write(@uart, data) 555 | end 556 | 557 | # Write a line data to a UART device. 558 | # This is a convenience method using #write 559 | # @see #write 560 | # 561 | # @param data the data to write 562 | # 563 | # @return Integer the number of bytes written 564 | # 565 | # @example 566 | # uart1.writeln("1234") => 5 567 | def writeln(data) 568 | UART::writeln(@uart, data) 569 | end 570 | 571 | # Read one character from a UART device 572 | # 573 | # @return String the character read from the UART device 574 | # 575 | # @example 576 | # uart1.readchars => "x" 577 | def readchar 578 | UART::readchar(@uart) 579 | end 580 | 581 | # Read characters from a UART device 582 | # 583 | # @param bytes number of bytes to read 584 | # 585 | # @return String the characters read from the UART device 586 | # 587 | # @example 588 | # uart1.readchars(2) => "xx" 589 | def readchars(bytes) 590 | UART::readchars(@uart, bytes) 591 | end 592 | 593 | # Read a line from a UART device 594 | # 595 | # @return String the line read from the UART device 596 | # 597 | # @example 598 | # uart1.readline => "A line of text" 599 | def readline 600 | UART::readline(@uart) 601 | end 602 | 603 | # Read a character from a UART device and pass it to the specified block 604 | # 605 | # @example 606 | # uart1.each_char { |x| puts "read: #{x}" } 607 | def each_char(&block) 608 | UART::each_char(@uart, &block) 609 | end 610 | 611 | # Read characters from a UART device and pass them to the specified block 612 | # 613 | # @param chars should be the number of chars to read 614 | # 615 | # @example 616 | # uart1.each_chars(2) { |x| puts "read: #{x}" } 617 | def each_chars(chars, &block) 618 | UART::each_chars(@uart, chars, &block) 619 | end 620 | 621 | # Read lines from a UART device and pass them to the specified block 622 | # 623 | # @example 624 | # uart1.each_line { |x| puts "read: #{x}" } 625 | def each_line(&block) 626 | UART::each_line(@uart, &block) 627 | end 628 | 629 | # Runs a callback after receiving a line of data from a UART device 630 | # This creates a new thread that runs in the background 631 | # 632 | # @param callback A method to call when the data is received. This method should take 3 arguments, the UART, the line read, and the counter 633 | # @param repeats is optional and specifies the number of times the callback will be run 634 | # 635 | # @example 636 | # callback = lambda { |uart, line, count| puts "[#{uart}:#{count}] #{line} "} 637 | # uart1.run_on_each_line(callback) 638 | def run_on_each_line(callback, repeats=nil) 639 | UART::run_on_each_line(callback, @uart, repeats) 640 | end 641 | 642 | # Convenience method for run_on_each_line with repeats set to 1 643 | # @see #run_on_each_line 644 | def run_once_on_each_line(callback) 645 | UART::run_once_on_each_line(callback, @uart) 646 | end 647 | 648 | # Runs a callback after receiving data from a UART device 649 | # This creates a new thread that runs in the background 650 | # 651 | # @param callback A method to call when the data is received. This method should take 3 arguments, the UART, the line read, and the counter 652 | # @param chars should be the number of chars to read 653 | # @param repeats is optional and specifies the number of times the callback will be run 654 | # 655 | # @example 656 | # callback = lambda { |uart, data, count| puts "[#{uart}:#{count}] #{data} "} 657 | # uart1.run_on_each_chars(callback, 2) 658 | def run_on_each_chars(callback, chars=1, repeats=nil) 659 | UART::run_on_each_chars(callback, @uart, chars, repeats) 660 | end 661 | 662 | # Convenience method for run_on_each_chars with chars and repeats set to 1 663 | # @see #run_on_each_chars 664 | def run_once_on_each_char(callback) 665 | UART::run_once_on_each_char(callback, @uart) 666 | end 667 | 668 | # Convenience method for run_on_each_chars with chars and repeats set to 1 669 | # @see #run_on_each_chars 670 | def run_once_on_each_chars(callback, chars=1) 671 | UART::run_once_on_each_chars(callback, @uart, chars) 672 | end 673 | 674 | # Convenience method for run_on_each_chars with chars set to 1 675 | # @see #run_on_each_chars 676 | def run_on_each_char(callback, repeats=nil) 677 | UART::run_on_each_char(callback, @uart, repeats) 678 | end 679 | 680 | # Stops any threads waiting for data on the specified UART 681 | def stop_read_wait 682 | UART::stop_read_wait(@uart) 683 | end 684 | 685 | # Disable a UART device. 686 | # 687 | # @note device trees cannot be unloaded at this time without kernel panic. 688 | def disable 689 | UART::disable(@uart) 690 | end 691 | 692 | end 693 | end 694 | -------------------------------------------------------------------------------- /procedural-examples.md: -------------------------------------------------------------------------------- 1 | **Table of Contents** 2 | - [Examples (Procedural)](#examples-procedural) 3 | - [GPIO](#gpio) 4 | - [GPIO Writing](#gpio-writing) 5 | - [GPIO Reading](#gpio-reading) 6 | - [LEDs](#leds) 7 | - [Edge Triggers](#edge-triggers) 8 | - [Edge Triggers in the Background](#edge-triggers-in-the-background) 9 | - [Shift Registers](#shift-registers) 10 | - [Analog Inputs](#analog-inputs) 11 | - [Reading](#reading) 12 | - [Waiting for Change](#waiting-for-change) 13 | - [Waiting for Change in the Background](#waiting-for-change-in-the-background) 14 | - [Waiting for Threshold](#waiting-for-threshold) 15 | - [Waiting for Threshold in the Background](#waiting-for-Threshold-in-the-background) 16 | - [PWM](#pwm) 17 | - [UART](#uart) 18 | - [UART Writing](#uart-writing) 19 | - [UART Reading](#uart-reading) 20 | - [UART Reading and Iterating](#uart-reading-and-iterating) 21 | - [UART Reading and Iterating in the Background](#uart-reading-and-iterating-in-the-background) 22 | - [I2C](#i2c) 23 | - [I2C Writing](#i2c-writing) 24 | - [I2C Reading](#i2c-reading) 25 | - [LSM303DLHC Example](#lsm303dlhc-example) 26 | - [SPI](#spi) 27 | - [SPI Data Transfer](#spi-data-transfer) 28 | - [MCP3008 Example](#mcp3008-example) 29 | 30 | ## Examples (Procedural) 31 | These examples will show the various ways to interact with the Beaglebones IO hardware. They will need to be executed as root in order to function correctly. 32 | 33 | ### GPIO 34 | The GPIO pins on the Beaglebone run at **3.3v**. Do not provide more than 3.3v to any GPIO pin or risk damaging the hardware. 35 | 36 | GPIO pins have two modes, input and output. These modes are represented by the symbols **:IN** and **:OUT**. 37 | 38 | GPIO pins have internal pullup and pulldown resistors. These modes are represented by the symbols **:PULLUP**, **:PULLDOWN**, and **:NONE**. 39 | 40 | GPIO pins have an adjustable slew rate. These modes are represented by the symbols **:FAST** and **:SLOW** 41 | To initialize the pin **P9_11**, pass the symbol for that pin and the mode to the **GPIO.pin_mode** method. 42 | 43 | ```ruby 44 | # Initialize pin P9_11 in INPUT mode 45 | # This method takes 4 arguments 46 | # pin: The pin to initialize 47 | # mode: The GPIO mode, :IN or :OUT 48 | # pullmode: (optional) The pull mode, :PULLUP, :PULLDOWN, or :NONE 49 | # slewrate: (optional) The slew rate, :FAST or :SLOW 50 | GPIO.pin_mode(:P9_11, :IN, :PULLUP, :FAST) 51 | 52 | # Initialize pin P9_12 in OUTPUT mode 53 | GPIO.pin_mode(:P9_12, :OUT) 54 | 55 | # Change pin P9_12 to INPUT mode 56 | GPIO.set_gpio_mode(:P9_12, :IN) 57 | 58 | # Disable pin P9_12 59 | GPIO.disable_gpio_pin(:P9_12) 60 | ``` 61 | 62 | #### GPIO Writing 63 | To set the state of a GPIO pin, the method **GPIO.digital_write** is used. The states that can be set are **:HIGH** to provide 3.3v and **:LOW** to provide ground. 64 | 65 | ```ruby 66 | # Initialize pin P9_12 in OUTPUT mode 67 | GPIO.pin_mode(:P9_12, :OUT) 68 | 69 | # Provide 3.3v on pin P9_12 70 | GPIO.digital_write(:P9_12, :HIGH) 71 | 72 | # Provide ground on pin P9_12 73 | GPIO.digital_write(:P9_12, :LOW) 74 | ``` 75 | 76 | #### GPIO Reading 77 | To read the current state of a GPIO pin, the method **GPIO.digital_read** is used. It will return the symbol **:HIGH** or **:LOW** depending on the state of the pin. 78 | 79 | ```ruby 80 | # Initialize pin P9_11 in INPUT mode 81 | GPIO.pin_mode(:P9_11, :IN) 82 | 83 | # Get the current state of P9_11 84 | state = GPIO.digital_read(:P9_11) => :LOW 85 | ``` 86 | 87 | #### LEDs 88 | The on-board LEDs are addressable via GPIO output. They are available on pins **:USR0** through **:USR3**. 89 | 90 | This example will blink each LED in order 5 times. 91 | 92 | ```ruby 93 | # Initialize each LED pin 94 | leds = [ :USR0, :USR1, :USR2, :USR3 ] 95 | leds.each do |ledpin| 96 | GPIO.pin_mode(ledpin, :OUT) 97 | end 98 | 99 | 100 | # Run the following block 5 times 101 | 5.times do 102 | # Iterate over each LED 103 | leds.each do |ledpin| 104 | # Turn on the LED 105 | GPIO.digital_write(ledpin, :HIGH) 106 | # Delay 0.25 seconds 107 | sleep 0.25 108 | # Turn off the LED 109 | GPIO.digital_write(ledpin, :LOW) 110 | end 111 | end 112 | ``` 113 | 114 | #### Edge Triggers 115 | The Beaglebone can also monitor for changes on a GPIO pin. This is called an edge trigger. Since this is interrupt based on the Beaglebone, waiting for a change does not waste CPU cycles by constantly polling the pin. 116 | 117 | The following trigger types are supported 118 | - Rising: Triggered when the state goes from low to high 119 | - Falling: Triggered when the state goes from high to low 120 | - Both: Triggered at any change in state 121 | - None: Triggering is disabled 122 | 123 | These trigger types are represented by the symbols :RISING, :FALLING, :BOTH, and :NONE 124 | 125 | This example will wait for a rising edge to continue, then output the type of edge trigger that was detected. 126 | 127 | ```ruby 128 | # Initialize pin P9_11 in INPUT mode 129 | GPIO.pin_mode(:P9_11, :IN) 130 | 131 | # Wait here until a rising edge is detected 132 | edge = GPIO.wait_for_edge(:P9_11, :RISING) => :RISING 133 | 134 | # Output the trigger type detected 135 | puts "Saw a #{edge} edge" 136 | ``` 137 | 138 | #### Edge Triggers in the Background 139 | To avoid blocking while waiting for an edge trigger, the method **GPIO.run_on_edge** will run a callback when an edge trigger is detected. This method will spawn a new thread and wait for an edge trigger in the background. Only one of these threads may be active per pin. 140 | 141 | This example will detect edge triggers in the background and output information when triggered. 142 | 143 | ```ruby 144 | # Initialize pin P9_11 in INPUT mode 145 | GPIO.pin_mode(:P9_11, :IN) 146 | 147 | # Define callback to run when an edge trigger is detected 148 | # This method takes 3 arguments. 149 | # pin: The pin that triggered the event 150 | # edge: The event that triggered it 151 | # count: How many times it has been triggered 152 | callback = lambda { |pin,edge,count| puts "[#{count}] #{pin} #{edge}"} 153 | 154 | # Run the callback every time a change in state is detected 155 | # This method has two additional arguments that are optional. 156 | # Timeout: How long to wait for an event before terminating the thread 157 | # Repeats: How many times to run the event 158 | # By default, it will run forever every time the specified trigger is detected 159 | GPIO.run_on_edge(callback, :P9_11, :BOTH) 160 | 161 | # This code will run immediately after the previous call, as it does not block 162 | sleep 10 163 | 164 | # Stop the background thread waiting for an edge trigger after 10 seconds 165 | GPIO.stop_edge_wait(:P9_11) 166 | 167 | # This convenience method will run the callback only on the first detected change 168 | GPIO.run_once_on_edge(callback, :P9_11, :BOTH) 169 | 170 | # Change the trigger detection for the specified pin 171 | GPIO.set_gpio_edge(:P9_11, :RISING) 172 | ``` 173 | 174 | #### Shift Registers 175 | This library will also support writing to shift registers using GPIO pins. Create a **ShiftRegister** object by initializing it with the latch pin, clock pin, and data pin. 176 | 177 | This example will trigger 8 pins of a shift register. 178 | 179 | ```ruby 180 | # P9_11 is connected to the latch pin 181 | # P9_12 is connected to the clock pin 182 | # P9_13 is connected to the data pin 183 | 184 | # Initialize the pins connected to shift register 185 | GPIO.pin_mode(:P9_11, :OUT) 186 | GPIO.pin_mode(:P9_12, :OUT) 187 | GPIO.pin_mode(:P9_13, :OUT) 188 | 189 | # Write value to shift register 190 | GPIO.shift_out(:P9_11, :P9_12, :P9_13, 0b11111111) 191 | ``` 192 | 193 | ### Analog Inputs 194 | The Analog pins on the Beaglebone run at **1.8v**. Do not provide more than 1.8v to any analog pin or risk damaging the hardware. The header has pins available to provide a 1.8v for analog devices as well as a dedicated analog ground. Analog pins are only capable of reading input values. 195 | 196 | Analog pins do not require setup, and can be read at any time 197 | 198 | #### Reading 199 | To read the value from an analog pin, the method **AIN.read** is used. This will return a value between 0 and 1799. 200 | 201 | ```ruby 202 | # Read the input value in millivolts. 203 | mv = AIN.read(:P9_33) => 1799 204 | ``` 205 | 206 | #### Waiting for Change 207 | To wait for the value of an analog pin to change by a specified voltage, the method **AIN.wait_for_change** is used. 208 | 209 | **AIN.wait_for_change** takes the following arguments. 210 | - pin: The symbol of the pin to monitor 211 | - mv_change: The amount of change in millivolts required before returning 212 | - interval: How often to poll the value of the pin in seconds 213 | - mv_last: (optional) The initial value to use as a point to detect change 214 | 215 | This method returns an array containing the initial voltage, the last polled voltage, and the number of times the pin was polled. 216 | 217 | ```ruby 218 | # Wait for 100mv of change on pin P9_33. Poll 10 times a second 219 | mv_start, mv_current, count = AIN.wait_for_change(:P9_33, 100, 0.1) 220 | ``` 221 | 222 | #### Waiting for Change in the Background 223 | To avoid blocking while waiting for voltage change, the method **AIN.run_on_change** will run a callback every time the specified change is detected. This method will spawn a new thread and wait for change in the background. The method **AIN.run_once_on_change** is a convenience method to only be triggered once. Only one of these threads may be active per pin. 224 | 225 | This example waits for voltage change in the background and outputs information when change is detected. 226 | 227 | ```ruby 228 | 229 | # Define callback to run when condition is met 230 | # This method takes 4 arguments. 231 | # pin: The pin that triggered the event 232 | # mv_last: The initial voltage used to determine change 233 | # mv: The current voltage on the pin 234 | # count: How many times it has been triggered 235 | callback = lambda { |pin, mv_last, mv, count| puts "[#{count}] #{pin} #{mv_last} -> #{mv}" } 236 | 237 | # Run the callback every time the specified voltage change is detected 238 | # This method has one additional argument that is optional. 239 | # Repeats: How many times to will run the event 240 | # By default, it will run forever every time the specified condition is detected 241 | # Detect 10mv of change polling 10 times a second. 242 | AIN.run_on_change(callback, :P9_33, 10, 0.1) 243 | 244 | # This code will run immediately after the previous call, as it does not block 245 | sleep 20 246 | 247 | # Stop the background thread after 20 seconds 248 | AIN.stop_wait(:P9_33) 249 | ``` 250 | 251 | #### Waiting for Threshold 252 | To wait for the value of an analog pin to cross certain threshold voltages, the method **AIN.wait_for_threshold** is used. 253 | 254 | **AIN.wait_for_threshold** takes the following arguments. 255 | - pin: The symbol of the pin to monitor 256 | - mv_lower: The lower threshold value in millivolts 257 | - mv_upper: The upper threshold value in millivolts 258 | - mv_reset: The voltage change required to cross out of the lower or upper threshold ranges. 259 | - interval: How often to poll the value of the pin in seconds 260 | - mv_last: (optional) The initial value to use as a point to detect change 261 | - state_last: (optional) The initial state to use as a point to detect change 262 | 263 | Three states are available. 264 | - :LOW: below or equal to mv_lower 265 | - :MID: above mv_lower and below mv_upper 266 | - :HIGH: above or equal to mv_upper 267 | 268 | This method returns an array containing the initial voltage, the last polled voltage, the initial state, the last polled state, and the number of times the pin was polled. 269 | 270 | ```ruby 271 | # Wait for the voltage on pin P9_33 to go below 200mv or above 1600mv. 272 | # To enter the :MID state from :HIGH or :LOW, it will have to cross the thresholds by at least 100mv. 273 | # Poll 10 times a second 274 | data = AIN.wait_for_threshold(:P9_33, 200, 1600, 100, 0.1) => [ 500, 150, :MID, :LOW, 53 ] 275 | 276 | # Assign variables from array 277 | mv_start, mv_current, state_start, state_current, count = data 278 | ``` 279 | 280 | #### Waiting for Threshold in the Background 281 | To avoid blocking while waiting for a voltage threshold to be crossed, the method **AIN.run_on_threshold** will run a callback every time the specified change is detected. This method will spawn a new thread and wait for change in the background. The method **AIN.run_once_on_threshold** is a convenience method to only be triggered once. Only one of these threads may be active per pin. 282 | 283 | This example waits for voltage change in the background and outputs information when the specified threshold is crossed. 284 | 285 | ```ruby 286 | # Define callback to run when condition is met 287 | # This method takes 6 arguments. 288 | # pin: The pin that triggered the event 289 | # mv_last: The initial voltage used to determine change 290 | # mv: The current voltage on the pin 291 | # state_last: The initial state to use as a point to detect change 292 | # state: The current state of the pin 293 | # count: How many times it has been triggered 294 | callback = lambda { |pin, mv_last, mv, state_last, state, count| 295 | puts "[#{count}] #{pin} #{state_last} -> #{state} #{mv_last} -> #{mv}" 296 | } 297 | 298 | # Run the callback every time the specified voltage threshold is crossed 299 | # This method has one additional argument that is optional. 300 | # Repeats: How many times to will run the event 301 | # By default, it will run forever every time the specified condition is detected 302 | # Wait for the voltage on pin P9_33 to go below 200mv or above 1600mv. 303 | # To enter the :MID state from :HIGH or :LOW, it will have to cross the thresholds by at least 100mv. 304 | # Poll 10 times a second 305 | # Run callback when state changes 306 | AIN.run_on_threshold(callback, :P9_33, 200, 1600, 100, 0.1) 307 | 308 | # This code will run immediately after the previous call, as it does not block 309 | sleep 20 310 | 311 | # Stop the background thread after 20 seconds 312 | AIN.stop_wait(:P9_33) 313 | ``` 314 | 315 | ### PWM 316 | The beaglebone supports PWM (pulse width modulated) output on certain pins. These pins output 3.3v. The output is controlled based on frequency and duty cycle. 317 | 318 | To initialize the pin **P9_14**, pass the symbol for that pin, the duty cycle, and the frequency in Hz to the **PWM.start** method. 319 | 320 | This example shows how to control PWM output of a specified pin. 321 | 322 | ```ruby 323 | # Initialize pin P9_14 for PWM output 324 | # This pin will now output a square wave at 10Hz with a 90% duty cycle, non-inverted. 325 | PWM.start(:P9_14, 90, 10, :NORMAL) 326 | 327 | # Change frequency to 20Hz. Duty cycle remains 90% 328 | PWM.set_frequency(:P9_14, 20) 329 | 330 | # Change the duty cycle to 50% 331 | PWM.set_duty_cycle(:P9_14, 50) 332 | 333 | # Adjust the frequency by setting the period in nanoseconds. 334 | PWM.set_period_ns(:P9_14, 31250000) 335 | 336 | # Adjust the duty cycle by setting the period in nanoseconds. 337 | PWM.set_duty_cycle_ns(:P9_14, 31250000) 338 | 339 | # Invert the output signal 340 | PWM.set_polarity(:P9_14, :INVERTED) 341 | 342 | # Stop the output signal 343 | PWM.stop(:P9_14) 344 | 345 | # Resume the output signal 346 | PWM.run(:P9_14) 347 | 348 | # Disable the output signal 349 | PWM.disable_pwm_pin(:P9_14) 350 | ``` 351 | 352 | ### UART 353 | The beaglebone has a number of UART devices. These operate in TTL mode at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 354 | 355 | Please note, UART3 does not have an RX pin, and UART5 is only available if the HDMI device tree is not enabled. 356 | 357 | To initialize the UART device **UART1**, pass the symbol for that device and the speed to the **UART.setup** method. 358 | 359 | ```ruby 360 | # Initialize the pins for device UART1 into UART mode. 361 | UART.setup(:UART1, 9600) 362 | 363 | # Change the speed of a UART device by calling #set_speed 364 | UART.set_speed(:UART1, 115200) 365 | 366 | # Disable UART device 367 | UART.disable(:UART1) 368 | ``` 369 | 370 | #### UART Writing 371 | Writing to a UART device is accomplished by calling the **UART.write** or **UART.writeln** methods 372 | ```ruby 373 | # Initialize the pins for device UART1 into UART mode. 374 | UART.setup(:UART1, 9600) 375 | 376 | # Write data to a UART1 377 | UART.write(:UART1, "DATA DATA DATA!") 378 | 379 | # Write data to UART1 followed by a line feed 380 | UART.writeln(:UART1, "A line feed follows") 381 | ``` 382 | 383 | #### UART Reading 384 | There are many methods available for reading from UART devices. These are blocking methods and will not return until the requested data is available. 385 | 386 | ```ruby 387 | # Initialize the pins for device UART1 into UART mode. 388 | UART.setup(:UART1, 9600) 389 | 390 | # Read one character from UART1 391 | c = UART.readchar(:UART1) => "X" 392 | 393 | # Read 10 characters from UART1 394 | str = UART.readchars(:UART1, 10) => "0123456789" 395 | 396 | # Read a line from UART1 397 | line = UART.readline(:UART1) => "All the text up until the linefeed" 398 | ``` 399 | 400 | #### UART Reading and Iterating 401 | Data read from the UART device may be iterated with the following methods. These are blocking methods and will run until the loop is broken. 402 | 403 | ```ruby 404 | # Initialize the pins for device UART1 into UART mode. 405 | UART.setup(:UART1, 9600) 406 | 407 | # Run block on every character read from UART1 408 | UART.each_char(:UART1) { |c| puts c } 409 | 410 | # Run block on every 5 character read from UART1 411 | UART.each_char(:UART1, 5) { |str| puts str } 412 | 413 | # Run block on each line read from UART1 414 | UART.each_line(:UART1) { |line| puts line } 415 | ``` 416 | 417 | #### UART Reading and Iterating in the Background 418 | Data read from the UART device may be iterated in the background with the following methods. The data read is passed to the specified callback. These method will spawn a new thread and wait for data in the background. Only one of these threads may be active per pin. 419 | 420 | This example shows various methods of reading and processing data read from UART1 in the background. 421 | 422 | ```ruby 423 | # Initialize the pins for device UART1 into UART mode. 424 | UART.setup(:UART1, 9600) 425 | 426 | # Define the callback to be run. It takes 3 arguments 427 | # uart: the UART device that triggered the callback 428 | # data: the data read from the UART 429 | # count: how many times this was triggered 430 | callback = lambda { |uart, data, count| puts "[#{uart}:#{count}] #{data}" } 431 | 432 | # Run callback for every character read 433 | UART.run_on_each_char(callback, :UART1) 434 | 435 | # Run callback for every 3 characters read 436 | UART.run_on_each_chars(callback, :UART1, 3) 437 | 438 | # Run callback for every line read 439 | UART.run_on_each_line(callback, :UART1) 440 | 441 | # Run callback once after a character is read 442 | UART.run_once_on_each_char(callback, :UART1) 443 | 444 | # Run callback once after 3 characters are read 445 | UART.run_once_on_each_chars(callback, :UART1, 3) 446 | 447 | # Run callback once after reading a line 448 | UART.run_once_on_each_line(callback, :UART1) 449 | 450 | # Stop the currently running background thread 451 | UART.stop_read_wait(:UART1) 452 | ``` 453 | 454 | ### I2C 455 | The beaglebone has a number of I2C devices. These operate at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 456 | 457 | To initialize the I2C device **I2C2**, pass the symbol for that device to the **I2C.setup** method. 458 | 459 | ```ruby 460 | # Initialize I2C device I2C2 461 | I2CDevice.setup(:I2C2) 462 | ``` 463 | 464 | #### I2C Writing 465 | To write to an I2C device, the method **I2C.write** is used. 466 | 467 | **I2C.write** takes the following arguments. 468 | - i2c: symbol of the I2C device to write to 469 | - address: address of slave device 470 | - data: data to write 471 | 472 | #### I2C Reading 473 | To read from an I2C device, the method **I2C.read** is used. 474 | 475 | **I2C.read** takes the following arguments. 476 | - i2c: symbol of the I2C device to read from 477 | - address: address of slave device 478 | - bytes: bytes to read 479 | - register: (optional) register to start reading from 480 | 481 | #### LSM303DLHC Example 482 | 483 | This example communicates with an [LSM303DLHC](https://www.adafruit.com/products/1120) Accelerometer/Compass/Thermometer device. 484 | 485 | ```ruby 486 | #!/usr/bin/env ruby 487 | require 'beaglebone' 488 | include Beaglebone 489 | 490 | # Initialize I2C device I2C2 491 | I2CDevice.setup(:I2C2) 492 | 493 | # Put compass into continuous conversation mode 494 | I2C.write(:I2C2, 0x1e, [0x02, 0x00].pack("C*")) 495 | 496 | # Enable temperatuer sensor, 15hz register update 497 | I2C.write(:I2C2, 0x1e, [0x00, 0b10010000].pack("C*") ) 498 | 499 | # Delay for the settings to take effect 500 | sleep(0.1) 501 | 502 | # Read axis data. It is made up of 3 big endian signed shorts starting at register 0x03 503 | raw = I2C.read(:I2C2, 0x1e, 6, [0x03].pack("C*")) 504 | 505 | # Coordinates are big endian signed shorts in x,z,y order 506 | x,z,y = raw.unpack("s>*") 507 | 508 | # Calculate angle of degrees from North 509 | degrees = (Math::atan2(y, x) * 180) / Math::PI 510 | degrees += 360 if degrees < 0 511 | 512 | # Read 2 byte big endian signed short from temperature register 513 | raw = I2C.read(:I2C2, 0x1e, 2, [0x31].pack("C*")) 514 | 515 | # Temperature is sent big endian, least significant digit last 516 | temp = raw.unpack("s>").first 517 | 518 | # Temperature data is 12 bits, last 4 are unused 519 | temp = temp >> 4 520 | 521 | # Each bit is 8c 522 | temp /= 8 523 | 524 | # Correction factor 525 | temp += 18 526 | 527 | # Convert to f 528 | temp = (temp * 1.8 + 32).to_i 529 | 530 | # Output data 531 | puts "#{Time.now.strftime("%H:%M")} Temperature: #{temp} degrees f Direction: #{degrees.to_i} degrees" 532 | 533 | # Disable I2C device 534 | I2C.disable(:I2C2) 535 | ``` 536 | 537 | ### SPI 538 | The beaglebone has a number of SPI devices. These operate at 3.3v. Do not provide more than 3.3v to the pins or risk damaging the hardware. 539 | 540 | To initialize the SPI device **SPI0**, pass the symbol for that device to the **SPI.setup** method. 541 | 542 | The optional arguments are also available 543 | - mode: SPI mode, :SPI_MODE_0 through :SPI_MODE_3 544 | - speed: Speed of the SPI device 545 | - bpw: Bits per word 546 | 547 | ```ruby 548 | # Initialize SPI device SPI0 549 | SPI.setup(:SPI0, :SPI_MODE_0, 1000000, 8) 550 | 551 | # You can change SPI with the methods below. 552 | 553 | # Set mode of SPI0 554 | SPI.set_mode(:SPI0, :SPI_MODE_3) 555 | 556 | # Set speed of SPI0 557 | SPI.set_speed(:SPI0, 100000) 558 | 559 | # Set bits per word of SPI0 560 | SPI.set_bpw(:SPI0, 10) 561 | 562 | # Disable SPI device 563 | SPI.disable(:SPI0) 564 | ``` 565 | 566 | #### SPI Data Transfer 567 | To transfer data to an SPI device, the method **SPI.xfer** is used. 568 | 569 | **SPI.xfer** takes the following arguments 570 | - spi: symbol for the SPI device to use 571 | - tx_data: data to transmit 572 | - readbytes: (optional) number of bytes to read, otherwise it sizeof tx_data is used 573 | - speed: (optional) speed of the transfer 574 | - delay: (optional) delay 575 | - bpw: (optonal) bits per word 576 | 577 | **SPI.xfer** returns the data read from the SPI device. 578 | 579 | #### MCP3008 Example 580 | This example communicates with an [MCP3008](http://www.adafruit.com/products/856) ADC device. 581 | 582 | ```ruby 583 | #!/usr/bin/env ruby 584 | require 'beaglebone' 585 | include Beaglebone 586 | 587 | # Initialize SPI device SPI0 588 | SPIDevice.new(:SPI0) 589 | 590 | # communicate with MCP3008 591 | # byte 1: start bit 592 | # byte 2: single(1)/diff(0),3 bites for channel, null pad 593 | # byte 3: don't care 594 | # Read value from channel 0 595 | raw = SPI.xfer(:SPI0, [ 0b00000001, 0b10000000, 0].pack("C*")) 596 | 597 | # Split data read into an array of characters 598 | data = raw.unpack("C*") 599 | 600 | # The returned data is stored starting at the last two bits of the second byte 601 | val = ((data[1] & 0b00000011) << 8 ) | data[2] 602 | 603 | # Display the value of channel 0 604 | puts "Value of channel 0: #{val}" 605 | 606 | # Read value from channel 1 607 | raw = SPI.xfer(:SPI0, [ 0b00000001, 0b10010000, 0].pack("C*")) 608 | 609 | # Split data read into an array of characters 610 | data = raw.unpack("C*") 611 | 612 | # The returned data is stored starting at the last two bits of the second byte 613 | val = ((data[1] & 0b00000011) << 8 ) | data[2] 614 | 615 | # Display the value of channel 1 616 | puts "Value of channel 1: #{val}" 617 | 618 | # Disable SPI device 619 | SPI.disable(:SPI0) 620 | ``` 621 | --------------------------------------------------------------------------------