radio.onReceivedString(function (receivedString) {
    if (receivedString == "Abstand!") {
        if (radio.receivedPacket(RadioPacketProperty.SignalStrength) > -65) {
            basic.setLedColor(0xff0000)
            basic.showIcon(IconNames.Sad)
        } else {
            basic.setLedColor(0x00ff00)
            basic.showIcon(IconNames.Happy)
        }
    }
})
radio.setGroup(1)
radio.setTransmitPower(3)
basic.forever(function () {
    radio.sendString("Abstand!")
    basic.pause(5000)
})