from machine import Pin, PWM
from time import sleep

cr = PWM(Pin(12))
cv = PWM(Pin(14))
cb = PWM(Pin(27))
buz = PWM(Pin(13))

while True:
    cr.duty(1023)
    cv.duty(0)
    cb.duty(0)
    buz.freq(440)
    buz.duty(1023)
    sleep(0.5)
    cr.duty(1023)
    cv.duty(1023)
    cb.duty(1023)
    buz.freq(880)
    buz.duty(1023)
    sleep(0.5)