from machine import Pin
import time

button1 = Pin(19, Pin.IN, Pin.PULL_DOWN)
button2 = Pin(17, Pin.IN, Pin.PULL_DOWN)
button3 = Pin(15, Pin.IN, Pin.PULL_DOWN)

while True:
  if button1.value() == 1:
    print("STOP")
  elif button2.value() == 1:
    print("READY")
  elif button3.value() == 1:
    print("GO")
  else:
    print("WAIT")
  time.sleep(0.5)