Stop screen from dimming by enforcing wake lock in Android

public class DoNotDimScreen extends Activity  {

private PowerManager.WakeLock wl;

@Override
protected void onCreate(Bundle savedInstanceState) {
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "DoNotDimScreen");
}

@Override
protected void onPause() {
super.onPause();
wl.release();
}

@Override
protected void onResume() {
super.onResume();
wl.acquire();
}
}

You will need to include this permission in your manifest:
<uses-permission android:name="android.permission.WAKE_LOCK" />