├── .gitignore
├── README.md
└── dmx.py


/.gitignore:
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1 | *.pyb
2 | 


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/README.md:
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 1 | #pyb_DMX
 2 | This module tries to make it slightly simpler to send DMX512 messages to lights
 3 | 
 4 | Here is a very simple example of how it works, ideally ```write_frame()``` should be done on a timer interrupt as DMX lights expect a regular message
 5 | 
 6 | ```python
 7 | # create a dmx device on UART port 1
 8 | dmx1 = dmx.universe(1)
 9 | 
10 | # Set the channel(s) to the value you want
11 | DMX1.set_channels({1:i})
12 | 
13 | # Send the message
14 | DMX1.write_frame()
15 | ```
16 | 
17 | thanks to this website for useful details
18 | [http://www.ubasics.com/DMX-512]
19 | 


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/dmx.py:
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 1 | from pyb import UART, Pin, udelay
 2 | from array import array
 3 | 
 4 | tx_pins = [None, 'X9', 'X3', 'Y9', 'X1', None, 'Y1']
 5 | 
 6 | class universe():
 7 |     def __init__(self, port):
 8 |         self.port = port
 9 | 
10 |         # To check if port is valid
11 |         dmx_uart = UART(port)
12 |         del(dmx_uart)
13 | 
14 |         # First byte is always 0, 512 after that is the 512 channels
15 |         self.dmx_message = array('B', [0] * 513)
16 | 
17 |     def set_channels(self, message):
18 |         """
19 |         a dict and writes them to the array
20 |         format {channel:value}
21 |         """
22 | 
23 |         for ch in message:
24 |             self.dmx_message[ch] = message[ch]
25 | 
26 |         # for i, ch in enumerate(channels):
27 |         #     self.dmx_message[ch] = values[i]
28 | 
29 |     def write_frame(self):
30 |         """
31 |         Send a DMX frame
32 |         """
33 |         # DMX needs a 88us low to begin a frame,
34 |         # 77uS us used because of time it takes to init pin
35 |         dmx_uart = Pin(tx_pins[self.port], Pin.OUT_PP)
36 |         dmx_uart.value(0)
37 |         udelay(74)
38 |         dmx_uart.value(1)
39 | 
40 |         # Now turn into a UART port and send DMX data
41 |         dmx_uart = UART(self.port)
42 |         dmx_uart.init(250000, bits=8, parity=None, stop=2)
43 |         #send bytes
44 |         dmx_uart.write(self.dmx_message)
45 |         #Delete as its going to change anyway
46 |         del(dmx_uart)
47 | 


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