import machine
import network
import time

# because we use onbaord GPIO, we invert the meaning of the pin
# so 0 turns it on, 1 turn it off
pin = machine.Pin(16, machine.Pin.OUT)
def poff(): pin.value(1)
def pon(): pin.value(0)
poff()

def tmain1():
    wlan = network.WLAN(network.STA_IF)
    try:
        while True:
            wlan.active(True)
            try:
                nets = wlan.scan()
                pon()
            except OSError:
                poff()
            wlan.active(False)
            time.sleep_ms(500)
    finally:
        poff()
        wlan.active(False)

tmain1()