from machine import Pin
import time
led1=Pin(23,Pin.OUT)
led2=Pin(22,Pin.OUT)
led3=Pin(21,Pin.OUT)
buzzer=Pin(18,Pin.OUT)
while True:
led1.on()
led2.off()
led3.off()
buzzer.value(1)
time.sleep(0.5)
led1.on()
led2.on()
led3.off()
buzzer.value(1)
time.sleep(0.5)
led1.on()
led2.on()
led3.on()
buzzer.value(0)
time.sleep(0.5)
led1.off()
led2.off()
led3.off()
buzzer.value(0)
time.sleep(0.5)