import RPi.GPIO as GPIO
import time
import sys

class PWM:
  def __init__(self, pin):
    self.pin = pin
    GPIO.setup(self.pin, GPIO.OUT)
    GPIO.output(self.pin, 0)
    self.pwm = GPIO.PWM(self.pin, 100)
    self.pwm.start(0)

  def setDutyCycle(self, val):
    self.pwm.ChangeDutyCycle(val)

if __name__ == '__main__':
  try:
    GPIO.setmode(GPIO.BCM)
    p = PWM(32)
    while True:
      p.setDutyCycle(int(time.time()*100 % 100))
      time.sleep(.03)
  except KeyboardInterrupt:
    GPIO.cleanup()
    sys.exit(0)