mapping joystick axis to specific 'channels' in python

mapping joystick axis to specific 'channels' in python - Printable Version

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mapping joystick axis to specific 'channels' in python - DashOrion - Jul-07-2020

I'm fairly new to python and I just can't come up with an adequate and elegant solution for my simple first program in python. I hope anyone more experienced can help. The program takes input from a (hid) joystick (using pygame) and outputs a standardized signal (SBUS) over UART to control a rc model/robot.

takes input from a (hid) joystick axis (0 - many available) (in my case a yoke or steering wheel) (float of -1 to 1)
maps the input value to a INT (int from 192 to 1792)
write the specific channel to a particular SBUS channel (20 channels available) (it's a communication protocol used in the RC world)
encode the SBUS frame to a bytearray and sent it out over serial

What I want to do/what the problem is: All is working fine, but I want be able to easily map a specific joystick axes to a specific SBUS channel. For now in a config file, in the future user selectable in a gui (PyQt based I think).

e.g. I want to do:

map joystick axis 0 to sbus channel 3.
map joystick axis 1 to sbus channel 1.
map joystick axis 2 to sbus channel 0.
etc

I'm not sure however how to do this in an easy way, with what datastructure and with the least amount of lines (e.g. in a for loop).

This is the part that I want to write better, in some sort of way with a dictionary or list for mapping joystick axis to sbus channels:

value_roll = joystick.get_axis(0)
value_pitch = joystick.get_axis(1)
value_throttle = joystick.get_axis(2)

mapped_value_roll = map(value_roll,-1,1,192,1792)
mapped_value_pitch = map(value_pitch, -1, 1, 1792, 192)
mapped_value_throttle = map(value_throttle, -1, 1, 1792, 192)


sbusOutput.set_channel(3, int(mapped_value_roll))
sbusOutput.set_channel(1, int(mapped_value_pitch))
sbusOutput.set_channel(0, int(mapped_value_throttle))

I hope somebody can help me to get my head around an elegant way to do this. Thanks already!

RE: mapping joystick axis to specific 'channels' in python - DashOrion - Jul-07-2020

Ok, so I now made it like this, mapping channels to joystick axis with a dictionary:

sbusChannel_to_JoystickAxis = {
    0: 3,
    1: 5,
    8: 2,
}

for sbusChannel, joystickaxis in sbusChannel_to_JoystickAxis.items():
    
    rawValue = get_axis[joystickaxis]
    mapped_value = map(rawValue,-1,1,192,1792)

    sbusOutput.set_channel(sbusChannel, int(mapped_value))

Is this the proper way and best way to do it? Or is there a better way?