Observable.interval(0, 1, TimeUnit.SECONDS)
.take(10)
.observeOn(AndroidSchedulers.mainThread())
.subscribeOn(Schedulers.computation())
.subscribe(new Observer<Long>() {
@Override
public void onSubscribe(Disposable d) {
}

@Override
public void onNext(Long aLong) {
txvText.setText(aLong.toString()); }

@Override
public void onError(Throwable e) {

}

@Override
public void onComplete() {

}
});