from machine import Pin
from time import sleep

relay1 = Pin(19, Pin.OUT)
relay2 = Pin(18, Pin.OUT)
relay3 = Pin(5, Pin.OUT)
relay4 = Pin(17, Pin.OUT)

bt1 = Pin(12, Pin.IN, Pin.PULL_UP)
bt2 = Pin(14, Pin.IN, Pin.PULL_UP)
bt3 = Pin(27, Pin.IN, Pin.PULL_UP)
bt4 = Pin(26, Pin.IN, Pin.PULL_UP)

while True:

    ### เงื่อนไขในการเขียนเป็น If elif
    if bt1.value() == 0:
        relay1.value( not relay1.value())
        while bt1.value() == 0:
            sleep(0.1)