import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

RUNNING = True

# PINs
red = 20
green = 21
blue = 22

# frequency for PWM
freq = 50

GPIO.setup(red, GPIO.OUT)
GPIO.setup(green, GPIO.OUT)
GPIO.setup(blue, GPIO.OUT)

# defining the pins that are going to be used with PWM
RED = GPIO.PWM(red, freq)
GREEN = GPIO.PWM(green, freq)
BLUE = GPIO.PWM(blue, freq)

colors = [RED,GREEN,BLUE]

try:
	while RUNNING:
		RED.start(100)
		GREEN.start(1)
		BLUE.start(1)
		
		for x in range(3):
			full = colors[x]
			up = colors[(x+1)%3]
			zero = colors[(x+2)%3]

			full.ChangeDutyCycle(100)
			zero.ChangeDutyCycle(1)
			
			# Keep one color at 100%, let another raise from 1% to 100% and leave the third at 1%
			for y in range(1,101):
				up.ChangeDutyCycle(y)
				time.sleep(0.01)

			# Now keep the raised color at 100% and dim the original full color down to 1%
			for y in range(1,101):
				full.ChangeDutyCycle(100-y)
				time.sleep(0.01)

except KeyboardInterrupt:
	RUNNING = False
	GPIO.cleanup()