ValueError Invalid literal for int() in _binaryadd for TMC429/TMC262 system

[astrophysaxist]

Hi,

I discovered a type mismatch when running a controller board using the TMC429 and TMC262. It is a USB device (MCST 3601), but I managed to get the commands working correctly with an edit to TMCL/bus.py.

The specific error was:

>>> motor.rotate_left(1234)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "TMCL/motor.py", line 67, in rotate_left
    reply = self.send(Command.ROL, 0, self.motor_id, velocity)
  File "TMCL/motor.py", line 53, in send
    return self.bus.send(self.module_id, cmd, type, motorbank, value)
  File "TMCL/bus.py", line 51, in send
    checksum = self._binaryadd(address, command, type, motorbank, value)
  File "TMCL/bus.py", line 101, in _binaryadd
    checksum += int(s) % 256
ValueError: invalid literal for int() with base 10: '\x01'

When I changed line 101 in TMCL/bus.py from:

checksum += int(s) % 256

to

checksum += int(s.encode('hex'),16) % 256

Things seemed to operate normally without error. I'm not sure if this is just a newer controller or driver board issue or related to the USB-to-serial conversion happening. Let me know if you'd like me to submit a pull request either way.

Thanks, Greg