import machine
import utime

redLED = machine.Pin(16, machine.Pin.OUT)
yellowLED = machine.Pin(17, machine.Pin.OUT)
greenLED = machine.Pin(18, machine.Pin.OUT)

button1 = machine.Pin(10, machine.Pin.IN, machine.Pin.PULL_DOWN)
button2 = machine.Pin(11, machine.Pin.IN, machine.Pin.PULL_DOWN)
button3 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN)

def activate_led(led):
    led.value(1) 
    utime.sleep(3) 
    led.value(0)  

while True:
    if button1.value():
        activate_led(redLED)
    if button2.value():
        activate_led(yellowLED)
    if button3.value():
        activate_led(greenLED)