laser_test.py

import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)

GPIO.setup(15,GPIO.OUT);

pin = GPIO.PWM(15,500);

pin.start(0)

try:
   while 1:
	
      	br = input("Brightness (max 100)");
      	if br>100:
		br = 100;
	if br<0:
		br = 0;

        pin.ChangeDutyCycle(br);
except KeyboardInterrupt:
   pass

pin.ChangeDutyCycle(0);

pin.stop();


GPIO.cleanup();