old_contents: #!/usr/bin/python
  
  from Adafruit_PWM_Servo_Driver import PWM
  import time
  
  # ===========================================================================
  # Example Code
  # ===========================================================================
  
  # Initialise the PWM device using the default address
  # bmp = PWM(0x40, debug=True)
  pwm = PWM(0x40, debug=True)
  
  servoMin = 150  # Min pulse length out of 4096
  servoMax = 600  # Max pulse length out of 4096
  
  def setServoPulse(channel, pulse):
    pulseLength = 1000000                   # 1,000,000 us per second
    pulseLength /= 60                       # 60 Hz
    print "%d us per period" % pulseLength
    pulseLength /= 4096                     # 12 bits of resolution
    print "%d us per bit" % pulseLength
    pulse *= 1000
    pulse /= pulseLength
    pwm.setPWM(channel, 0, pulse)
  
  pwm.setPWMFreq(60)                        # Set frequency to 60 Hz
  while (True):
    # Change speed of continuous servo on channel O
    pwm.setPWM(0, 0, servoMin)
    time.sleep(1)
    pwm.setPWM(0, 0, servoMax)
    time.sleep(1)
  
new_contents: #!/usr/bin/python
  
  from Adafruit_PWM_Servo_Driver import PWM
  import time
  
  # ===========================================================================
  # Example Code
  # ===========================================================================
  
  # Initialise the PWM device using the default address
  # bmp = PWM(0x40, debug=True)
  pwm = PWM(0x40, debug=True)
  
  servoMin = 200  # Min pulse length out of 4096 (1 ms = 200/4095 x 20ms)
  servoNeutral = 300 # neutral pulse length out of 4096 (1.5ms = 300/4095 x 20ms)
  servoMax = 400  # Max pulse length out of 4096 (2ms = 400/4095 x 20ms)
  
  pwm.setPWMFreq(50)  # Set frequency to 50 Hz (servo pulse period = 20ms)
  while (True):
  	# Change speed of continuous servo on channel O
  	pwm.setPWM(0, 0, servoMin)
  	time.sleep(1)
  	pwm.setPWM(0, 0, servoNeutral)
  	time.sleep(1)
  	pwm.setPWM(0, 0, servoMax)
  	time.sleep(1)
  	pwm.setPWM(0, 0, servoNeutral)
  	time.sleep(1)
  
subject: Update example.py