gistfile1.txt

val conn = device.establishConnection(false)

conn
    .flatMap(rxBleConnection -> rxBleConnection.setupNotification(battTxCharUuid))
    .doOnNext(notificationObservable -> {
        conn.writeCharacteristic(battRxCharUuid,cmd).subscribe();
    })
    .flatMap(notificationObservable -> notificationObservable) // <-- Notification has been set up, now observe value changes.
    .subscribe(
        bytes -> {
            // Given characteristic has been changes, here is the value.
        },
        throwable -> {
            // Handle an error here.
        }
    );