Error trying to connect to Stepper using python

[packetfocus]

New install. I configured the WS to use station wireless, and verified I can connect through the website and run commands on my nema 17 stepper.

Having problems running python commands. Using python 3.7, and imported the library in the directory.

Also changed the host name using IP in the py code.

C:\code\WifiStepper2>python ws.py
Traceback (most recent call last):
File "ws.py", line 12, in
MOTOR.connect()
File "C:\code\WifiStepper2\goodrobotics.py", line 452, in connect
return self.__comm.connect()
File "C:\code\WifiStepper2\goodrobotics.py", line 211, in connect
return self.cmd_ping(0, 0)
File "C:\code\WifiStepper2\goodrobotics.py", line 228, in cmd_ping
return self._waitreply(self._send(self._OPCODE_PING, self._SUBCODE_CMD, target, queue), self._SUBCODE_ACK)
File "C:\code\WifiStepper2\goodrobotics.py", line 367, in _send
self.sock.send(self._preamble(self._TYPE_STD) + self._header(opcode, subcode, target, queue, packetid, len(data)) + data)
TypeError: can't concat str to bytes

C:\code\WifiStepper2>python --version
Python 3.7.0

[packetfocus]

================ EXAMPLE PYTHON CODE - Use chunks as needed ================

For full documentation see https://www.wifistepper.com/interfaces

import goodrobotics as gr

host = "192.168.1.107"

Create motor object

MOTOR = gr.WifiStepper(host=host)

MOTOR = gr.WifiStepper(proto=gr.ComCrypto, host=host, key="<AUTH_KEY>") # For crypto auth

Connect (will throw exception on failure)

MOTOR.connect()

Write motor configuration

MOTOR.setconfig({
'mode': "current", 'stepsize': 8,
'ocd': 500, 'ocdshutdown': True,
'maxspeed': 10000, 'minspeed': 0, 'accel': 1000, 'decel': 1000,
'cm_kthold': 1.7000000000000002, 'cm_ktrun': 1.7000000000000002, 'cm_ktaccel': 1.7000000000000002, 'cm_ktdecel': 1.7000000000000002,
'fsspeed': 2000, 'fsboost': False,
'cm_switchperiod': 44, 'cm_predict': True,
'cm_minon': 21, 'cm_minoff': 21, 'cm_fastoff': 4, 'cm_faststep': 20,
'reverse': False, 'save': True
})

Read configuration

config = MOTOR.getconfig()

config is a dict() of configuration map

Send speed command

rpm = gr.RPM()
MOTOR.run(dir=MOTOR.FORWARD, stepss=rpm(30))

Emergency stop motor

MOTOR.estop()

Read status

state = MOTOR.getstate()

state is a dict() with keys: busy, stepss, hiz, vin, pos, mark, dir, movement, stepclock, switch,

flags=dict( switch, commanderror, overcurrent, undervoltage, thermalwarning,

thermalshutdown, stalldetect )

[packetfocus]

this is the function that seems to be throwing the error.

self.sock.send(self._preamble(self._TYPE_STD) + self._header(opcode, subcode, target, queue, packetid, len(data)) + data)

return packetid

is this an issue connecting, or possible issue with the "data" variable string type?

[packetfocus]

I can issue commands with curl without issues:

C:\code\WifiStepper>curl -sS "http://192.168.1.107/api/motor/run?dir=forward&stepss=100"
{"status":"ok","id":27}
C:\code\WifiStepper>curl -sS "http://192.168.1.107/api/motor/state"
{"stepss":0,"pos":15539,"mark":0,"vin":13.28125,"dir":"forward","movement":"idle","hiz":true,"busy":false,"switch":false,"stepclock":false,"alarms":{"commanderror":false,"overcurrent":fa
lse,"undervoltage":false,"thermalshutdown":false,"thermalwarning":false,"stalldetect":false,"switch":false},"signal":{"value":0,"modified":0},"command":{"thisid":0,"lastid":27,"completed
":2920524},"now":2947616,"status":"ok"}
C:\code\WifiStepper>

[aklofas]

Ah, this must be an issue with python 3.7 not auto-converting between bytes and strings.

[alexrudd2]

Ah, this must be an issue with python 3.7 not auto-converting between bytes and strings.

@aklofas Yes, that's exactly it - the code does not work on Python 3. The pull request I have linked fixes it, while maintaining Python 2 compatibility.