├── LICENSE ├── README.md ├── examples ├── buffered │ └── buffered.ino └── not_buffered │ └── not_buffered.ino ├── keywords.txt ├── library.properties └── src ├── CANSerial.cpp └── CANSerial.h /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. By contrast, 15 | the GNU General Public License is intended to guarantee your freedom to 16 | share and change all versions of a program--to make sure it remains free 17 | software for all its users. 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It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 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 | Copyright (C) 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 | . 675 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # CANSerial 2 | 3 | Use CAN bus as physical layer for serial/uart communication. 4 | Aheres to Stream interface, so it can be used exactly like a regular Serial port. Supports multiple concurrent objects when used in cunjunction with included Buffered_MCP_CAN class. Designed to interface with https://github.com/bondus/CanSerial/ 5 | 6 | ## History 7 | One day I found myself needing an additional serial port on my Arduino nano. Because it's based on the atmega328p it only has one hardware port. Normally, I'd just use SoftwareSerial, but I was already using that for something else. I also happened to already have my device connected to a CAN bus and I was debugging the messages being sent out. 8 | 9 | It then occured to me that instead of trying to make another SoftwareSerial and adding more wires to the mix (and another uart adapter on the computer), I could just pipe those debug messages over the CAN bus too. 10 | 11 | After looking around online, I eventuially found https://github.com/bondus/CanSerial/ which claims to be obsolete. I took a look anyways and figured that it would work fine on the computer side of things. I just needed to write the Arduino side "client" code, and that's how we got here. 12 | 13 | After some initial testing that worked really well it became apparent that the ability to have multiple objects on a device would be great and I still needed a way to still read the CAN bus from my project. This led to the creation of the Buffered_MCP_CAN class. It buffers received CAN frames and exposes the ability for a buffer-aware client to read them while keeping them in the buffer for other clients to read. 14 | 15 | ## ...Ok, but WHY? 16 | In one word, convenience. 17 | Imagine this example. You have a project based on an Arduino nano. It has a GPS module connected to SoftwareSerial and sends GPS data out over a CAN bus. It also has a bluetooth to serail module connected so it can be controlled via a phone app. As you work on this project, something isn't working. Normally you might start doing some `Serial.println("debug message");` at different lines in your code to see whats going on, but alas, you don't have a spare Serial port. 18 | With CANSerial, you just create a new CANSerial object and `println` your debug output there. 19 | One other handy thing. By using CANSerial, you can have your debug messages always available on the bus without needing to physically connect more wires to your MCU. It's also trivial to keep debug messages separate from "real" communication data without extra wires. 20 | 21 | ## Usage 22 | This library is actually two libraries in one. CANSerial is the star of the show, but Buffered_MCP_CAN is in there too. 23 | CANSerial can be used in one of two ways; either directly with an MCP_CAN object or using an intermediary Buffered_MCP_CAN. 24 | 25 | Direct usage of MCP_CAN has the following problems: 26 | - Unable to have more than one CANSerial Object 27 | - Unable to read from the CAN bus with any other part of the program. 28 | 29 | These problems are fixed by wrapping access to the CAN object in Buffered_MCP_CAN, examples for each are included in the `examples/` folder. 30 | 31 | #### Requirements 32 | ##### Seeed_Arduino_CAN 33 | I cannot possibly know what hardware you might be using and in what configuration, so I won't attempt to explain how to get your CAN interface working. This library is designed to work with Seeed_Arduino_CAN and either an mcp2515 or mcp2518fd. 34 | You will probably have something like the following to have a working CAN interface: 35 | ``` 36 | // CAN Constants 37 | const int SPI_CS_PIN = 10; 38 | mcp2515_can CAN(SPI_CS_PIN); // Set CS pin 39 | ``` 40 | ... 41 | ``` 42 | void setup() { 43 | // CAN Setup 44 | while (CAN_OK != CAN.begin(CAN_500KBPS,MCP_12MHz)) { // init can bus : baudrate = 500k 45 | Serial.println("CAN ERROR"); 46 | delay(100); 47 | } 48 | } 49 | ``` 50 | ##### Setup 51 | To add CANSerial to the above, include the header: 52 | ``` 53 | #include 54 | ``` 55 | 56 | --- 57 | Declare an object, passing in a "base address" and your CAN object: 58 | ``` 59 | CANSerial CS(0x6E0,CAN); 60 | ``` 61 | Or, if using Buffered_MCP_CAN: 62 | ``` 63 | Buffered_MCP_CAN bufCAN(CAN); 64 | CANSerial CS(0x6E0,bufCAN); 65 | ``` 66 | Notice that `CAN` is passed to Buffered_MCP_CAN and then the Buffered_MCP_CAN object is passed to CANSerial. 67 | 68 | The "base address" is what lets this client library and the PC server software mentioned above talk to each other. It needs to match `PKT_ID_UUID_FILTER` from `cansock.h` in the [CanSerial utility program](https://github.com/bondus/CanSerial/). 69 | 70 | --- 71 | UUIDs for this are a maximum of 6 bytes, they need to be unique on your network for each device, not necessary to be pseudo-random. 72 | In `setup()` add: 73 | ``` 74 | static unsigned char UUID[_CS_UUID_SIZE] = {0xCE, 0xF2, 0x35, 0x2C, 0xE1, 0xB3}; 75 | CS.begin(UUID,_CS_UUID_SIZE); 76 | ``` 77 | 78 | --- 79 | Finally, use it: 80 | ``` 81 | loop( 82 | // Periodic calls to .available(), one of the .print() functions or .read() etc 83 | // are necessary for the library to perform address negotiation and heartbeat 84 | CS.println("Hello"); 85 | delay(1000); 86 | ) 87 | ``` 88 | 89 | --- 90 | ##### Utility program 91 | [CanSerial utility program](https://github.com/bondus/CanSerial/) 92 | Clone the repository. Edit cansock.h Build it, run it. 93 | It prints out handy messages when something connects and tells you the virtual tty device name to open. 94 | 95 | #### Memory Usage 96 | A quick note about memory usage. 97 | Buffered_MCP_CAN buffers CAN frames. Each frame requires 13 bytes of RAM, so the buffer size is critical for RAM usage. By default it is set to 16 which seems to work well with a couple objects using it. Depending on your program structure, you may need to increase `_CAN_MAX_RX_BUF` to a larger value to prevent buffer rollovers where data gets lost because it is overwritten before it gets read. Be careful, when testing, I set `_CAN_MAX_RX_BUF` to 64 and RAM was almost full causing strange errors because local variables started getting written to wrong places. I recommend going as large as you can while keeping static RAM usage under about 80% to give the best chance of error-free operation. 98 | 99 | ## Issues 100 | This library has been tested to work in several configurations. It probably has edge cases that completely break it. Future updates to Seeed_Arduino_CAN could also break it. 101 | If you find an issue, [Report it](https://github.com/techie66/CANSerial/issues/new) 102 | 103 | ## Contributing 104 | All pull requests welcome! 105 | 106 | ## License 107 | Licensed under GPLv3, see LICENSE file for details. 108 | -------------------------------------------------------------------------------- /examples/buffered/buffered.ino: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | 4 | // CAN Constants 5 | const int SPI_CS_PIN = 10; 6 | mcp2515_can CAN(SPI_CS_PIN); // Set CS pin 7 | 8 | Buffered_MCP_CAN bufCAN(CAN); 9 | CANSerial CS1(0x6E0,bufCAN); 10 | CANSerial CS2(0x6E0,bufCAN); 11 | 12 | void setup() { 13 | Serial.begin(115200); 14 | Serial.println("Startup initiated!"); 15 | 16 | // CAN Setup 17 | while (CAN_OK != CAN.begin(CAN_500KBPS,MCP_12MHz)) { // init can bus : baudrate = 500k 18 | Serial.println("CAN ERROR"); 19 | delay(100); 20 | } 21 | 22 | // Uncomment the following line if hardware is setup to enable transceiver from MCP PIO 23 | CAN.mcpPinMode(MCP_RX0BF,MCP_PIN_OUT); 24 | 25 | static unsigned char UUID1[_CS_UUID_SIZE] = {0xCE, 0xF2, 0x35, 0x2C, 0xE1, 0xB1}; 26 | CS1.begin(UUID1,_CS_UUID_SIZE); 27 | static unsigned char UUID2[_CS_UUID_SIZE] = {0xCE, 0xF2, 0x35, 0x2C, 0xE1, 0xB2}; 28 | CS2.begin(UUID2,_CS_UUID_SIZE); 29 | } 30 | 31 | void loop() { 32 | CS1.println("First"); 33 | CS2.println("Second"); 34 | delay(1000); 35 | } 36 | -------------------------------------------------------------------------------- /examples/not_buffered/not_buffered.ino: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | 4 | // CAN Constants 5 | const int SPI_CS_PIN = 10; 6 | mcp2515_can CAN(SPI_CS_PIN); // Set CS pin 7 | 8 | CANSerial CS(0x6E0,CAN); 9 | 10 | void setup() { 11 | Serial.begin(115200); 12 | Serial.println("Startup initiated!"); 13 | 14 | // CAN Setup 15 | while (CAN_OK != CAN.begin(CAN_500KBPS,MCP_12MHz)) { // init can bus : baudrate = 500k 16 | Serial.println("CAN ERROR"); 17 | delay(100); 18 | } 19 | 20 | // Uncomment the following line if hardware is setup to enable transceiver from MCP PIO 21 | CAN.mcpPinMode(MCP_RX0BF,MCP_PIN_OUT); 22 | 23 | static unsigned char UUID[_CS_UUID_SIZE] = {0xCE, 0xF2, 0x35, 0x2C, 0xE1, 0xB3}; 24 | CS.begin(UUID,_CS_UUID_SIZE); 25 | } 26 | 27 | void loop() { 28 | CS.println("Hello"); 29 | delay(1000); 30 | } 31 | -------------------------------------------------------------------------------- /keywords.txt: -------------------------------------------------------------------------------- 1 | # Syntax Coloring Map For CANSerial 2 | 3 | # Datatypes (KEYWORD1) 4 | Buffered_MCP_CAN KEYWORD1 5 | CANSerial KEYWORD1 6 | 7 | # Methods and Functions (KEYWORD2) 8 | enableTxInterrupt KEYWORD2 9 | reserveTxBuffers KEYWORD2 10 | getLastTxBuffer KEYWORD2 11 | setSleepWakeup KEYWORD2 12 | sleep KEYWORD2 13 | wake KEYWORD2 14 | setMode KEYWORD2 15 | getMode KEYWORD2 16 | readMsgBufID KEYWORD2 17 | trySendMsgBuf KEYWORD2 18 | sendMsgBuf KEYWORD2 19 | clearBufferTransmitIfFlags KEYWORD2 20 | readRxTxStatus KEYWORD2 21 | checkClearRxStatus KEYWORD2 22 | checkClearTxStatus KEYWORD2 23 | mcpPinMode KEYWORD2 24 | mcpDigitalWrite KEYWORD2 25 | mcpDigitalRead KEYWORD2 26 | 27 | isBuffered KEYWORD2 28 | 29 | 30 | # Structures (KEYWORD3) 31 | can_frame KEYWORD3 32 | 33 | # Instances (KEYWORD2) 34 | 35 | 36 | # Constants (LITERAL1) 37 | _CS_UUID_SIZE LITERAL1 38 | _CS_MAX_RX_BUFF LITERAL1 39 | _CS_MAX_TX_BUFF LITERAL1 40 | GCC_VERSION LITERAL1 41 | _CAN_MAX_RX_BUF LITERAL1 42 | CAN_EFF_FLAG LITERAL1 43 | CAN_RTR_FLAG LITERAL1 44 | CAN_ERR_FLAG LITERAL1 45 | CAN_SFF_MASK LITERAL1 46 | CAN_EFF_MASK LITERAL1 47 | CAN_ERR_MASK LITERAL1 48 | 49 | -------------------------------------------------------------------------------- /library.properties: -------------------------------------------------------------------------------- 1 | name=CANSerial 2 | version=0.2.0 3 | author=Jacob Geigle 4 | maintainer=Jacob Geigle 5 | sentence=Use CAN bus as physical layer for serial/uart communication 6 | paragraph=Aheres to Stream interface, so it can be used exactly like a regular Serial port. Supports multiple concurrent objects when used in cunjunction with included Buffered_MCP_CAN class. Designed to interface with https://github.com/bondus/CanSerial/ 7 | category=Communication 8 | url=http://www.github.com/techie66/CANSerial 9 | architectures=* 10 | includes=CANSerial.h 11 | depends=Seeed_Arduino_CAN 12 | -------------------------------------------------------------------------------- /src/CANSerial.cpp: -------------------------------------------------------------------------------- 1 | /** 2 | * CANSerial 3 | * Arduino Library to emulate a uart over a CAN bus. 4 | * Designed to interface with https://github.com/bondus/CanSerial/ 5 | * 6 | * Copyright (C) 2022 Jacob Geigle 7 | * 8 | * This program is free software; you can redistribute it and/or modify 9 | * it under the terms of the GNU General Public License as published by 10 | * the Free Software Foundation; either version 3 of the License, or 11 | * (at your option) any later version. 12 | * 13 | * This program is distributed in the hope that it will be useful, 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 | * GNU General Public License for more details. 17 | * 18 | * You should have received a copy of the GNU General Public License along 19 | * with this program; if not, write to the Free Software Foundation, Inc., 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 21 | */ 22 | #include "CANSerial.h" 23 | 24 | // 25 | // Constructor 26 | // 27 | CANSerial::CANSerial(uint16_t baseID, MCP_CAN &CAN_Object, bool inverse_logic /* = false */) : 28 | _baseID(baseID), 29 | _CAN_Object(&CAN_Object), 30 | _Buffered_CAN_Object(NULL), 31 | _buffer_overflow(false), 32 | _inverse_logic(inverse_logic), 33 | _heartbeat(millis()), 34 | _validID(false), 35 | _usingBufferedCAN(false) 36 | { 37 | } 38 | 39 | // 40 | // Constructor 41 | // (Buffered_MCP_CAN) 42 | // 43 | CANSerial::CANSerial(uint16_t baseID, Buffered_MCP_CAN &CAN_Object, bool inverse_logic /* = false */) : 44 | _baseID(baseID), 45 | _CAN_Object(&CAN_Object), 46 | _Buffered_CAN_Object(&CAN_Object), 47 | _buffer_overflow(false), 48 | _inverse_logic(inverse_logic), 49 | _heartbeat(millis()), 50 | _validID(false), 51 | _usingBufferedCAN(true) 52 | { 53 | } 54 | 55 | // 56 | // Destructor 57 | // 58 | CANSerial::~CANSerial() 59 | { 60 | end(); 61 | } 62 | 63 | void CANSerial::begin(unsigned char *UUID, size_t len) 64 | { 65 | for (size_t i=0; i < (len < _CS_UUID_SIZE ? len:_CS_UUID_SIZE); i++) { 66 | _UUID[i] = UUID[i]; 67 | } 68 | recv(); 69 | } 70 | 71 | void CANSerial::end() 72 | { 73 | } 74 | 75 | void CANSerial::recv() 76 | { 77 | unsigned char len = 0; 78 | unsigned char buf[8]; 79 | if (millis() - _heartbeat > 30000) { 80 | _validID = false; 81 | } 82 | if ( _usingBufferedCAN ) { 83 | if (CAN_MSGAVAIL == _Buffered_CAN_Object->checkReceive(_lCANBufHead)) { // check if data coming 84 | byte ret = _Buffered_CAN_Object->readMsgBuf(&len, buf, _lCANBufHead); // read data, len: data length, buf: data buf 85 | if ( ret == CAN_OK ) { 86 | _lCANBufHead = (_lCANBufHead + 1) % _CAN_MAX_RX_BUF; 87 | } 88 | processFrame(buf,len); 89 | } 90 | } 91 | else { 92 | if (CAN_MSGAVAIL == _CAN_Object->checkReceive()) { // check if data coming 93 | _CAN_Object->readMsgBuf(&len, buf); // read data, len: data length, buf: data buf 94 | processFrame(buf,len); 95 | } 96 | } 97 | send(); 98 | } 99 | 100 | /* 101 | * processFrame() 102 | * 103 | * process incoming frames 104 | */ 105 | void CANSerial::processFrame(unsigned char *buf, unsigned char len) 106 | { 107 | unsigned long canId = _CAN_Object->getCanId(); 108 | if (canId == _baseID+1 ) { 109 | _heartbeat = millis(); 110 | if (!_validID || _nodeID == buf[0] + (buf[1] * 0x100u)) { 111 | _CAN_Object->sendMsgBuf(_baseID+3,0,0,_CS_UUID_SIZE,_UUID); 112 | } 113 | } 114 | else if ( canId == _baseID+2 ) { 115 | bool lContinue = true; 116 | for ( int i = 0;i<_CS_UUID_SIZE;i++ ) { 117 | if (_UUID[i] != buf[i+2]) { 118 | lContinue = false; 119 | } 120 | } 121 | if (lContinue) { 122 | _nodeID = buf[0] + (buf[1] * 0x100); 123 | _validID = true; 124 | _heartbeat = millis(); 125 | } 126 | } 127 | else if (canId == _nodeID) { 128 | if (len == 0) { 129 | _CAN_Object->sendMsgBuf(_nodeID+1,0,0,0,NULL); 130 | } 131 | for (int i=0;isendMsgBuf(_nodeID+1,0,0,1,&_send_buffer[_send_buffer_head]); 172 | _send_buffer_head = (_send_buffer_head + 1) % _CS_MAX_TX_BUFF; 173 | count++; 174 | } 175 | } 176 | return count; 177 | } 178 | 179 | size_t CANSerial::write(uint8_t b) 180 | { 181 | recv(); 182 | if ( (_send_buffer_head - _send_buffer_tail) == 1 ){ 183 | _buffer_overflow = true; 184 | return -1; 185 | } 186 | _send_buffer[_send_buffer_tail] = b; 187 | _send_buffer_tail = (_send_buffer_tail + 1) % _CS_MAX_TX_BUFF; 188 | send(); 189 | return 1; 190 | } 191 | 192 | void CANSerial::flush() 193 | { 194 | // There is no tx buffering, simply return 195 | } 196 | 197 | int CANSerial::peek() 198 | { 199 | 200 | // Empty buffer? 201 | if (_receive_buffer_head == _receive_buffer_tail) 202 | return -1; 203 | 204 | // Read from "head" 205 | return _receive_buffer[_receive_buffer_head]; 206 | } 207 | 208 | /* 209 | * Buffered CAN_MCP 210 | */ 211 | 212 | /* 213 | * Constructor 214 | */ 215 | Buffered_MCP_CAN::Buffered_MCP_CAN(MCP_CAN &CAN_Object) : 216 | MCP_CAN(0), 217 | _CAN_Object(&CAN_Object) 218 | { 219 | } 220 | /* 221 | * Destructor 222 | */ 223 | Buffered_MCP_CAN::~Buffered_MCP_CAN(){} 224 | 225 | /* 226 | * readMsgBufID 227 | * the real workorse 228 | */ 229 | byte Buffered_MCP_CAN::readMsgBufID(byte status, volatile unsigned long *id, volatile byte *ext, volatile byte *rtr, volatile byte *len, volatile byte *buf, uint8_t extHead) 230 | { 231 | //TODO - Add check to extHead to make sure not overflowing (eg, bad implementation in client) 232 | byte ret = CAN_NOMSG; 233 | // Check if underlying device has received anything 234 | if ( _CAN_Object->checkReceive() == CAN_MSGAVAIL ) { 235 | // add to FIFO 236 | unsigned long newID; 237 | byte newExt; 238 | byte newRTR; 239 | byte newLen; 240 | byte newBuf[8]; 241 | byte res = _CAN_Object->readMsgBufID(status,&newID,&newExt,&newRTR,&newLen,(byte*)&newBuf); 242 | if ( res == CAN_OK ) { 243 | _canBuf[_RX_buf_tail].canid = newID; 244 | _canBuf[_RX_buf_tail].canid |= newExt ? CAN_EFF_FLAG : 0; 245 | _canBuf[_RX_buf_tail].canid |= newRTR ? CAN_RTR_FLAG : 0; 246 | _canBuf[_RX_buf_tail].len = newLen; 247 | for ( int i=0;icheckReceive(); 291 | if ( res == CAN_MSGAVAIL ) { 292 | return CAN_MSGAVAIL; 293 | } 294 | if ( ((_RX_buf_tail + _CAN_MAX_RX_BUF - extHead) % _CAN_MAX_RX_BUF) > 0 ) { 295 | return CAN_MSGAVAIL; 296 | } 297 | return CAN_NOMSG; 298 | } 299 | 300 | /* 301 | * checkReceive 302 | * checks underlying controller and internal buffer 303 | * wrapper for normal operation 304 | */ 305 | byte Buffered_MCP_CAN::checkReceive() 306 | { 307 | return checkReceive(_RX_buf_head); 308 | } 309 | 310 | /* 311 | * readRxTxStatus 312 | * checks underlying chip and adjusts based on items in buffer 313 | */ 314 | byte Buffered_MCP_CAN::readRxTxStatus(void) 315 | { 316 | //TODO 317 | // Maybe doesn't matter 318 | return _CAN_Object->readRxTxStatus(); 319 | } 320 | -------------------------------------------------------------------------------- /src/CANSerial.h: -------------------------------------------------------------------------------- 1 | /** 2 | * CANSerial 3 | * Arduino Library to emulate a uart over a CAN bus. 4 | * Designed to interface with https://github.com/bondus/CanSerial/ 5 | * 6 | * Copyright (C) 2022 Jacob Geigle 7 | * 8 | * This program is free software; you can redistribute it and/or modify 9 | * it under the terms of the GNU General Public License as published by 10 | * the Free Software Foundation; either version 3 of the License, or 11 | * (at your option) any later version. 12 | * 13 | * This program is distributed in the hope that it will be useful, 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 | * GNU General Public License for more details. 17 | * 18 | * You should have received a copy of the GNU General Public License along 19 | * with this program; if not, write to the Free Software Foundation, Inc., 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 21 | */ 22 | 23 | 24 | /** 25 | * Functions to Implement from regular serial API 26 | */ 27 | #ifndef CANSerial_h 28 | #define CANSerial_h 29 | 30 | #include 31 | #include 32 | #include 33 | 34 | /****************************************************************************** 35 | * Definitions 36 | ******************************************************************************/ 37 | 38 | #ifndef _CS_UUID_SIZE 39 | #define _CS_UUID_SIZE 6 // UUID size 40 | #endif 41 | 42 | #ifndef _CS_MAX_RX_BUFF 43 | #define _CS_MAX_RX_BUFF 64 // RX buffer size 44 | #endif 45 | 46 | #ifndef _CS_MAX_TX_BUFF 47 | #define _CS_MAX_TX_BUFF 8 // TX buffer size 48 | #endif 49 | 50 | #ifndef GCC_VERSION 51 | #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) 52 | #endif 53 | 54 | #ifndef _CAN_MAX_RX_BUF 55 | #define _CAN_MAX_RX_BUF 16 56 | #endif 57 | 58 | /* special address description flags for the CAN_ID */ 59 | #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */ 60 | #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */ 61 | #define CAN_ERR_FLAG 0x20000000U /* error message frame */ 62 | 63 | /* valid bits in CAN ID for frame formats */ 64 | #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */ 65 | #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */ 66 | #define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */ 67 | 68 | typedef struct can_frame { 69 | unsigned long canid=0; 70 | int len=0; 71 | byte data[8]={0}; 72 | }can_frame_t; 73 | 74 | class Buffered_MCP_CAN : public MCP_CAN 75 | { 76 | private: 77 | MCP_CAN *_CAN_Object; 78 | can_frame_t _canBuf[_CAN_MAX_RX_BUF]; 79 | volatile uint8_t _RX_buf_head; 80 | volatile uint8_t _RX_buf_tail; 81 | public: 82 | Buffered_MCP_CAN(MCP_CAN &CAN_Object); 83 | ~Buffered_MCP_CAN(); 84 | byte checkReceive(uint8_t extHead); 85 | byte readMsgBufID(byte status, volatile unsigned long *id, volatile byte *ext, volatile byte *rtr, volatile byte *len, volatile byte *buf, uint8_t extHead); 86 | public: 87 | virtual void enableTxInterrupt(bool enable = true) // enable transmit interrupt 88 | { 89 | _CAN_Object->enableTxInterrupt(enable); 90 | } 91 | virtual void reserveTxBuffers(byte nTxBuf = 0) 92 | { 93 | _CAN_Object->reserveTxBuffers(nTxBuf); 94 | } 95 | virtual byte getLastTxBuffer() 96 | { 97 | return _CAN_Object->getLastTxBuffer(); 98 | } 99 | virtual byte begin(uint32_t speedset, const byte clockset = MCP_16MHz) 100 | { 101 | return _CAN_Object->begin(speedset,clockset); 102 | } 103 | virtual byte init_Mask(byte num, byte ext, unsigned long ulData) 104 | { 105 | return _CAN_Object->init_Mask(num,ext,ulData); 106 | } 107 | virtual byte init_Filt(byte num, byte ext, unsigned long ulData) 108 | { 109 | return _CAN_Object->init_Filt(num,ext,ulData); 110 | } 111 | virtual void setSleepWakeup(byte enable) 112 | { 113 | _CAN_Object->setSleepWakeup(enable); 114 | } 115 | virtual byte sleep() 116 | { 117 | return _CAN_Object->sleep(); 118 | } 119 | virtual byte wake() 120 | { 121 | return _CAN_Object->wake(); 122 | } 123 | virtual byte setMode(byte opMode) 124 | { 125 | return _CAN_Object->setMode(opMode); 126 | } 127 | virtual byte getMode() 128 | { 129 | return _CAN_Object->getMode(); 130 | } 131 | virtual byte checkError(uint8_t* err_ptr = NULL) 132 | { 133 | return _CAN_Object->checkError(err_ptr); 134 | } 135 | 136 | virtual byte checkReceive(); 137 | virtual byte readMsgBufID(byte status, volatile unsigned long *id, volatile byte *ext, volatile byte *rtr, volatile byte *len, volatile byte *buf); 138 | /* wrapper */ 139 | byte readMsgBufID(unsigned long *ID, byte *len, byte *buf) { 140 | return readMsgBufID(readRxTxStatus(), ID, &ext_flg, &rtr, len, buf); 141 | } 142 | byte readMsgBuf(byte *len, byte *buf) { 143 | return readMsgBufID(readRxTxStatus(), &can_id, &ext_flg, &rtr, len, buf); 144 | } 145 | byte readMsgBuf(byte *len, byte *buf, uint8_t extHead) { 146 | return readMsgBufID(readRxTxStatus(), &can_id, &ext_flg, &rtr, len, buf, extHead); 147 | } 148 | 149 | virtual byte trySendMsgBuf(unsigned long id, byte ext, byte rtrBit, byte len, const byte *buf, byte iTxBuf = 0xff) 150 | { 151 | return _CAN_Object->trySendMsgBuf(id,ext,rtrBit,len,buf,iTxBuf); 152 | } 153 | virtual byte sendMsgBuf(byte status, unsigned long id, byte ext, byte rtrBit, byte len, volatile const byte *buf) 154 | { 155 | return _CAN_Object->sendMsgBuf(status,id,ext,rtrBit,len,buf); 156 | } 157 | virtual byte sendMsgBuf(unsigned long id, byte ext, byte rtrBit, byte len, const byte *buf, bool wait_sent = true) 158 | { 159 | return _CAN_Object->sendMsgBuf(id,ext,rtrBit,len,buf,wait_sent); 160 | } 161 | /* wrapper */ 162 | inline byte sendMsgBuf(unsigned long id, byte ext, byte len, const byte *buf) { 163 | return sendMsgBuf(id, ext, 0, len, buf, true); 164 | } 165 | 166 | virtual void clearBufferTransmitIfFlags(byte flags = 0) 167 | { 168 | _CAN_Object->clearBufferTransmitIfFlags(flags); 169 | } 170 | virtual byte readRxTxStatus(void); 171 | virtual byte checkClearRxStatus(byte *status) 172 | { 173 | return _CAN_Object->checkClearRxStatus(status); 174 | } 175 | virtual byte checkClearTxStatus(byte *status, byte iTxBuf = 0xff) 176 | { 177 | return _CAN_Object->checkClearTxStatus(status,iTxBuf); 178 | } 179 | virtual bool mcpPinMode(const byte pin, const byte mode) 180 | { 181 | return _CAN_Object->mcpPinMode(pin,mode); 182 | } 183 | virtual bool mcpDigitalWrite(const byte pin, const byte mode) 184 | { 185 | return _CAN_Object->mcpDigitalWrite(pin,mode); 186 | } 187 | virtual byte mcpDigitalRead(const byte pin) 188 | { 189 | return _CAN_Object->mcpDigitalRead(pin); 190 | } 191 | 192 | }; 193 | 194 | /* 195 | * CANSerial Class 196 | * transport serial communications over CAN bus 197 | */ 198 | 199 | class CANSerial : public Stream 200 | { 201 | private: 202 | // per object data 203 | uint16_t _baseID; 204 | MCP_CAN *_CAN_Object; 205 | Buffered_MCP_CAN *_Buffered_CAN_Object; 206 | uint16_t _buffer_overflow:1; 207 | uint16_t _inverse_logic:1; 208 | unsigned long _heartbeat; 209 | unsigned char _UUID[_CS_UUID_SIZE]; 210 | uint16_t _nodeID; 211 | bool _validID; 212 | uint8_t _receive_buffer[_CS_MAX_RX_BUFF]; 213 | volatile uint8_t _receive_buffer_tail; 214 | volatile uint8_t _receive_buffer_head; 215 | uint8_t _send_buffer[_CS_MAX_TX_BUFF]; 216 | volatile uint8_t _send_buffer_tail; 217 | volatile uint8_t _send_buffer_head; 218 | const bool _usingBufferedCAN; 219 | uint8_t _lCANBufHead = 0; 220 | 221 | void recv(); 222 | int send(); 223 | void processFrame(unsigned char *buf, unsigned char len); 224 | 225 | public: 226 | // public methods 227 | CANSerial(uint16_t baseID, MCP_CAN &CAN_Object, bool inverse_logic = false); 228 | CANSerial(uint16_t baseID, Buffered_MCP_CAN &CAN_Object, bool inverse_logic = false); 229 | ~CANSerial(); 230 | void begin(unsigned char *UUID, size_t len); 231 | void end(); 232 | bool overflow() { bool ret = _buffer_overflow; if (ret) _buffer_overflow = false; return ret; } 233 | int peek(); 234 | 235 | bool isBuffered() { return _usingBufferedCAN; } 236 | 237 | virtual size_t write(uint8_t byte); 238 | virtual int read(); 239 | virtual int available(); 240 | virtual void flush(); 241 | operator bool() { return true; } 242 | 243 | using Print::write; 244 | }; 245 | 246 | #endif 247 | --------------------------------------------------------------------------------