from machine import Pin,PWM
from time import sleep

# Pin configuration
led1 = Pin(18, Pin.OUT)
led2 = Pin(19, Pin.OUT)
led3 = Pin(20, Pin.OUT)
buzzer= PWM(Pin(8))

def buzzerSound(buzzz):
    buzzer.freq(500)
    buzzer.duty_u16(1000)
    sleep(1)
    buzzer.duty_u16(0)

def ledBlink(led):
    led.on()
    sleep(0.5)
    led.off()
    sleep(0.5)

while True:
    ledBlink(led1)
    ledBlink(led2)
    buzzerSound(buzzer)
    ledBlink(led3)
    ledBlink(led2)
    buzzerSound(buzzer)