from machine import Pin, PWM, DAC
from time import sleep

red = Pin(23,Pin.OUT)
yellow = Pin(22,Pin.OUT)
green= Pin(21,Pin.OUT)
buzzer = PWM(Pin(25),freq=1000)
push = Pin(14,Pin.IN,Pin.PULL_UP)

def semaforo (w,x,y,z):
    red.value(w)
    yellow.value(x)
    green.value(y)
    buzzer.duty(z)

n=i=0

while(1):
    if push.value()==0:
        sleep(0.03)
        n=n+1
        if n>1:
            n=0
        while push.value()==0:
            sleep(0.03)

    elif n==0:
        semaforo(1,0,0,0)
        sleep(1.5)

        semaforo(0,1,0,0)
        sleep(1.5)

        semaforo(0,0,1,0)
        sleep(1.5)

    else:
        semaforo(1,0,0,500)
        sleep(2)