Bug fix where each stepper motor references the same info list

[AaronYoung5]

Hi, thanks for making this package, I've found it very useful! (I think) I've run into a bug with the stepper_info_list. TL;DR the stepper_info_list is not copied between motor instances, so when you call a method that requires a callback, it will always overwrite all other instances. As in, all stepper motor instances share the same info list.

This code snippet reproduces the issue that I see:

from telemetrix import telemetrix
import time

board = telemetrix.Telemetrix()

def create_motor(pin1, pin2, enable):
    motor = board.set_pin_mode_stepper(pin1=pin1, pin2=pin2)
    board.stepper_set_enable_pin(motor, enable)
    board.stepper_set_3_pins_inverted(motor, enable=True)
    return motor

motorX = create_motor(2, 3, 8)
motorY = create_motor(4, 5, 8)

def current_position_callback_X(_):
    print('X')

def current_position_callback_Y(_):
    print('Y')

board.stepper_get_current_position(motorX, current_position_callback_X)
board.stepper_get_current_position(motorY, current_position_callback_Y)

time.sleep(1)

Which outputs:

Y
Y

Where the indented output (which is the result you get with the changes in this PR) is:

X
Y

I've created this PR assuming this is a bug, but maybe I'm using the library wrong. Please let me know if that's the case. Thanks again!

[MrYsLab]

Great catch! Thanks for the pull request. I think no one found this before because they use a single callback for all motors and then key off the motor ID.

I am going to release it to PyPi. I will add a comment here when it is available.

[MrYsLab]

Thanks once again. The release is available in PyPi.