public class mainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button bLightOn = (Button) findViewById(R.id.button1);
        bLightOn.setOnClickListener(new View.OnClickListener() {

			public void onClick(View v) {
				// TODO Auto-generated method stub
				Process process = null;
				DataOutputStream os = null;
				try {
					process = Runtime.getRuntime().exec("su");
					os = new DataOutputStream(process.getOutputStream());
					os.writeBytes("echo 0 > /sys/class/gpio/gpio168/value");
					os.writeBytes("cat /sys/class/gpio/gpio168/value \n");
					os.writeBytes("exit\n");
					os.flush();
					process.waitFor();

					} catch (Exception e) {
					return;
					}
					finally {
					try {
					if (os != null) {
					os.close();
					}
					process.destroy();
					} catch (Exception e) {
					// Be Happy :)
					}

			}
			}
			});