Multiple Arduinos

[polomarco87]

I am working with multiple ArduinoMega units. I've gotten this code to work extremely well when only 1 single Arduino is hooked up, but as soon as I hook up 2 or more, the input functions (related to the register callback, enable reporting, etc) default to the last defined Arduino board.

I have written an extremely simplified version of what I'm seeing:

import pyfirmata2
from pyfirmata2 import ArduinoMega, util

def pinCallback(value):
    if value:
        print("Button 1 released")
    else:
        print("Button 1 pressed")

def pinCallback1(value):
    if value:
        print("Button 2 released")
    else:
        print("Button 2 pressed")    

# Creates a new board
board = pyfirmata2.ArduinoMega('COM18')
board2 = pyfirmata2.ArduinoMega('COM19')
print("Setting up the connection to the board ...")

# default sampling interval of 19ms
board.samplingOn()
board2.samplingOn()

# Setup the digital pin with pullup resistor: "u"
digital_0 = board.get_pin('d:6:u')
digital_1 = board2.get_pin('d:6:u')

# points to the callback
digital_0.register_callback(pinCallback)
digital_1.register_callback(pinCallback1)

# Switches the callback on
digital_0.enable_reporting()
digital_1.enable_reporting()

print("To stop the program press return.")

input()

# Close the serial connection to the Arduino
board.exit()
board2.exit()

What I am seeing -- adjusting the pin (acting as a button) on board 1 will print "Button 2..." and likewise, adjust the pin on board 2 will print "Button 2..." If I swap the order of the board definitions, board2 following by board, then the opposite happens, and only "Button 1..." will print.

Is there a core function I'm missing to allow multiple, simultaneous serial communications with multiple Arduino boards?

[berndporr]

I think you are the 1st who tried it with two Arduinos. As you say it should work as they are totally separate in their instances. I can only guess that the previous maintainer has introduced a global variable somewhere.

[polomarco87]

If that is the case, I'd have to potentially search for and edit out some kind of global variable in the pyfirmata2.py code itself?

[berndporr]

It would be nice to find the bug and send me a pull request. :)

[polomarco87]

I don't have the longest experience with Python. From my short basic code I'm experimenting with, I confirmed that the initial board setups are being established, but I am wondering if one of the three input portions are overwriting each other: samplingOn, callback_register(), or enable_reporting()

I'll be looking more into how these are handled, but if you have any ideas if those may be defaulting to the "last called board" that would be great to know.

[polomarco87]

Okay, by moving each board into its own function and calling them one at a time, I've isolated the fault to be either due to the enable_reporting(), or register_callback() functions. Note my comments on those lines -- that describes the behavior when only one of those are disabled at a time. I do not understand enough about the pyfirmata2.py lines, particularly how there are two classes (Pin and Port) that have enable_reporting() in it.

I'm honestly baffled why this is happening, so any help would be greatly appreciated!

import pyfirmata2
from pyfirmata2 import ArduinoMega, util

def pinCallback(value):
    if value:
        print("Button 1 released")
    else:
        print("Button 1 pressed")

def pinCallback1(value):
    if value:
        print("Button 2 released")
    else:
        print("Button 2 pressed")    

# Creates a new board
def setupArd1():
    board = pyfirmata2.Arduino('COM18', name='Ard1')
    board.samplingOn()
    digital_0 = board.get_pin('d:6:u')
    digital_0.register_callback(pinCallback) #disabling this line only, both physical Arduino print Button 2
    digital_0.enable_reporting() #disabling this line only, both physical Arduino print Button 2

def setupArd2():
    board2 = pyfirmata2.Arduino('COM19', name='Ard2')
    board2.samplingOn()
    digital_1 = board2.get_pin('d:6:u')
    digital_1.register_callback(pinCallback1) #disabling this line only, neither Arduino will print anything
    digital_1.enable_reporting() #disabling this line only, both physical Arduino print Button 2

setupArd1()
setupArd2()

print("To stop the program press return.")

input()

# Close the serial connection to the Arduino
board.exit()
board2.exit()