Testing app QR code scanner with AndroidJunit.4

I am trying to create a test script for my MainActivity. This main class has a QR-code scanner. At this moment I can scan a QR-code while testing with my phone, however I want be able to do this with an emulator. The text in my QR-code contains only a string: "start1".

This is my test script:

@Test
    public void shouldRenderView() throws Exception {
        rule.launchActivity(new Intent());


        onView(withId(R.id.textStatus)).check(matches(withText("Inruimen")));

        onView(withId(R.id.scan_btn)).perform(click());
        pressBack();

        Thread.sleep(5000);
        //within this period I scan the code.

        onView(withId(R.id.textStatus)).check(matches(withText("draaien")));
    }