from machine import Pin
import utime

ledMerah = Pin(0,Pin.OUT)
ledKuning = Pin(1,Pin.OUT)
ledHijau = Pin(4,Pin.OUT)

while True:
    ledMerah.value(1)
    ledKuning.value(0)
    ledHijau.value(0)
    utime.sleep(0.5)

    ledMerah.value(0)
    ledKuning.value(1)
    ledHijau.value(0)
    utime.sleep(0.5)

    ledMerah.value(0)
    ledKuning.value(0)
    ledHijau.value(1)
    utime.sleep(0.5)