from microbit import *
import radio

chnl = 10
radio.config(channel=chnl)
radio.on()

while True:
    a = button_a.is_pressed()
    b = button_b.is_pressed()
    if  a:
        display.show(Image.ARROW_N)
        radio.send("N")
    elif b:
        display.show(Image.ARROW_S)
        radio.send("S")
    sleep(20)