from machine import Pin
from utime import sleep


led_R = Pin(22, Pin.OUT)
led_B = Pin(21, Pin.OUT)

def main():
    while True:
        sub_led()

def sub_led():
    led_R.on()
    sleep(0.5)
    led_R.off()
    sleep(0.5)

    led_B.on()
    sleep(0.5)
    led_B.off()
    sleep(0.5)  

if __name__ == '__main__':
    main()