from machine import Pin
import time

led_red=Pin(1,Pin.OUT)
led_blue=Pin(4,Pin.OUT)
led_yellow=Pin(26,Pin.OUT)

while True :
    led_red.value(1)
    time.sleep(4)
    led_red.value(0)
    led_blue.value(1)
    time.sleep(4)
    led_blue.value(0)
    led_yellow.value(1)
    time.sleep(4)
    led_yellow.value(0)