Robot Stay Inside Circular Ring

[webmanoffesto]

I have a Lego Mindstorms brick running ev3dev (open source Linux) and I am writing a Python program for it. I want to enter it in a friendly Sumo style robot competition. Two robots are put inside a circular ring and whoever pushes their opponent outside the ring wins. So I need an "avoid the line" or "stay inside the black line circle" program.

Here is an example video wwwDOTyoutubeDOTcom/watch?v=3tguWcKTXQI&t=110s
I still have to clarify exactly what the ring will be, black area outlined by white, or something different. But I think I can assume I'll be avoiding a bold black line, and I can change that later if I need to.

I'm running ev3dev, brickman v.0.8.0, kernel 4.4.24-16-ev3dev-ev3 on a Lego Mindstorms EV3 programmable brick, revision 0006
I'm using PyCharm IDE and I push the code to the brick over WiFi.

Error:
<ev3dev.core.LargeMotor object at 0xb6903e30>> ignored
robot@ev3dev:~/myproject$ python col-reflect-driveaway-v.2016.12.05.n01.py
0
Traceback (most recent call last):
  File "col-reflect-driveaway-v.2016.12.05.n01.py", line 38, in <module>
    m2.reset()
  File "/usr/lib/python2.7/dist-packages/ev3dev/core.py", line 738, in reset
    self.command = 'reset'
  File "/usr/lib/python2.7/dist-packages/ev3dev/core.py", line 295, in command
    self.set_attr_string('command', value)
  File "/usr/lib/python2.7/dist-packages/ev3dev/core.py", line 216, in set_attr_string
    self._set_attribute(attribute, "{0}".format(value))
  File "/usr/lib/python2.7/dist-packages/ev3dev/core.py", line 204, in _set_attribute
    self._attribute_cache.write(abspath(self._path + '/' + attribute), value)
AttributeError: 'LargeMotor' object has no attribute '_path'
Exception AttributeError: "'LargeMotor' object has no attribute '_path'" in <bound method LargeMotor.__del__ of <ev3dev.core.LargeMotor object at 0xb6960e30>> ignored
robot@ev3dev:~/myproject$ 

Program

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#!/usr/bin/env python3 # so that script can be run from Brickman   # I amd combining a "bump into wall, back up, turn 45 degrees, drive forward" program # and a color sensor col-reflect program # This is for a "sumo", robot inside of a circle outlined in black, drive forward, if sense black line then turn   # This code (or an earlier version of it) is posted at codepasteDOTnet/zrs5gq   from ev3dev.ev3 import * from time import sleep     ### col-reflect # Connect EV3 color sensor and check connected.   cl = ColorSensor() assert cl.connected, "Connect a color sensor to any sensor port"   # Put the color sensor into COL-REFLECT mode # to measure reflected light intensity. # In this mode the sensor will return a value between 0 and 100 cl.mode = 'COL-REFLECT'   while True:    print(cl.value())    sleep(0.5)      # I get max 80 with white paper, 3mm separation    # and 5 with black plastic, same separation      direction = 1 # Switches between 1 and -1      m = LargeMotor('outB')    m.reset()    m.run_forever(speed_sp=675 * direction)      m2 = LargeMotor('outA')    m2.reset()    m2.run_forever(speed_sp=675)      print(cl.value())    sleep(0.5)      new_color = cl.value()    print new_color    if new_color < 10:      direction *= -1  # Reverse the direction. Forward becomes backward, backward becomes forward      m.run_timed(time_sp=1000, speed_sp=300 * direction)      sleep(1)      print "I am sleeping"      direction *= -1  # Reverse the direction. Forward becomes backward, backward becomes forward      m.run_forever(speed_sp=675 * direction)    touch = new_touch #######

[webmanoffesto]

When I run the program with >python3 rather than just >python
I get the error
robot@ev3dev:~/myproject$ python3 col-reflect-driveaway-v.2016.12.05.n01.py
File "col-reflect-driveaway-v.2016.12.05.n01.py", line 45
print new_color
^
SyntaxError: Missing parentheses in call to 'print'

[micseydel]

Have you tried adding parenthesis in the call to 'print'?

[webmanoffesto]

Have you tried adding parenthesis in the call to 'print'?

Thank you, the "print" call is now working

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while True:    print(cl.value())    sleep(0.5)

Can you help me with the new problem I now have?
I'm now getting this error

Error:
robot@ev3dev:~/myproject$ python3 col-reflect-driveaway-v.2016.12.05.n01.py
0
Traceback (most recent call last):
  File "col-reflect-driveaway-v.2016.12.05.n01.py", line 48, in <module>
    m2.run_forever(speed_sp=675)
  File "/usr/lib/python3/dist-packages/ev3dev/core.py", line 756, in run_forever
    setattr(self, key, kwargs[key])
  File "/usr/lib/python3/dist-packages/ev3dev/core.py", line 546, in speed_sp
    self._speed_sp = self.set_attr_int(self._speed_sp, 'speed_sp', value)
  File "/usr/lib/python3/dist-packages/ev3dev/core.py", line 215, in set_attr_int
    return self._set_attribute(attribute, name, str(int(value)))
  File "/usr/lib/python3/dist-packages/ev3dev/core.py", line 208, in _set_attribute
    raise Exception('Device is not connected')
Exception: Device is not connected
robot@ev3dev:~/myproject$ packet_write_wait: Connection to 192.168.1.158 port 22: Broken pipe

The program starts running, for some reason it loses the WiFi connection, but the program keeps running, therefore CTRL-C doesn't stop it, and I have to reboot the Mindstorms brick.

You can see the most recent version of the code at: https://codepaste.net/zrs5gq

Edit admin:
Look at BBCode help button.
icode tag is only for short inline code.

[micseydel]

There might be someone around here that can help you, but you probably want a specialized forum for that device. It's hard to help when we lack domain knowledge and can't reproduce the problem.