radio.onReceivedString(function on_received_string(receivedString: string) {
    rcvd = receivedString
})

let rcvd = ""
let chnl = 10
radio.setGroup(chnl)

basic.forever(function on_forever() {
    if (!"this".isEmpty()) {
        if (rcvd.compare("N") == 0) {
            basic.showArrow(ArrowNames.North)
        } else if (rcvd.compare("S") == 0) {
            basic.showArrow(ArrowNames.South)
        }
        
    }
})