import time
import machine
time.sleep(0.1) # Wait for USB to become ready
led=machine.Pin(20,machine.Pin.OUT)
pin = machine.ADC(26)
while True:
    val = pin.read_u16()
    print(val)
    time.sleep(.2)
    if val<4000:
        led.on()
    else:
        
        led.off()