@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Chronometer simpleChronometer = (Chronometer) findViewById(R.id.chronometer);
        simpleChronometer.setOnChronometerTickListener(new Chronometer.OnChronometerTickListener() {

            @Override
            public void onChronometerTick(Chronometer chronometer) {
                long elapsedMillis = SystemClock.elapsedRealtime() - chronometer.getBase();
                if(elapsedMillis > 0) chronometer.stop();
            }
        });
    }

    public void startuoti(View view)
    {
        Chronometer chronometer = (Chronometer)findViewById(R.id.chronometer);
        chronometer.setBase(SystemClock.elapsedRealtime() + 10000);
        chronometer.setCountDown(true);
        chronometer.start();
    }