My own version of drive_in_square.py

drive_in_square.py

#! /usr/bin/env python
#  drive_in_square.py
import time
import pibot
import sys

bot = pibot.PiBot()
# speed = 255
speed = 64

if len( sys.argv ) > 1:
    speed = int( sys.argv[ 1 ] )
   
while True:

    # Drive forward
    bot.setMotorSpeeds( speed, speed )
    time.sleep( 3.0 )

    # Turn right
    bot.setMotorSpeeds( speed, -speed )
    time.sleep( speed /(255*4.0) )