from machine import Pin  
from time import sleep   

red_pin = Pin(4, Pin.OUT)     
green_pin = Pin(0, Pin.OUT)   
blue_pin = Pin(2, Pin.OUT)    

def sub_rgb_led():
    # LED states: 0 = ON, 1 = OFF
    red_pin.value(0)     # Turn ON Red LED
    green_pin.value(1)   # Turn OFF Green LED
    blue_pin.value(1)    # Turn OFF Blue LED
    sleep(0.5)           # Wait 0.5 seconds

    red_pin.value(1)     # Turn OFF Red LED
    green_pin.value(0)   # Turn ON Green LED
    blue_pin.value(1)    # Turn OFF Blue LED
    sleep(0.5)           # Wait 0.5 seconds

    red_pin.value(1)     # Turn OFF Red LED
    green_pin.value(1)   # Turn OFF Green LED
    blue_pin.value(0)    # Turn ON Blue LED
    sleep(0.5)           # Wait 0.5 seconds          


while True:             
    sub_rgb_led()