BLE Toy Train Controlled by Smartphone

package com.redbear.moterDrive_BLEnano02;

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.MenuItem;
import android.widget.TextView;

import com.developwear.joystickview.JoystickView;

public class Ctl extends Activity {
	private final static String TAG = Ctl.class.getSimpleName();

	public static final String EXTRAS_DEVICE = "EXTRAS_DEVICE";
	private TextView tv = null;
	private JoystickView jsv;

	private String mDeviceName;
	private String mDeviceAddress;
	private RBLService mBluetoothLeService;
	private Map<UUID, BluetoothGattCharacteristic> map = new HashMap<UUID, BluetoothGattCharacteristic>();

	private int bleState = 0;

	private final ServiceConnection mServiceConnection = new ServiceConnection() {

		@Override
		public void onServiceConnected(ComponentName componentName,
				IBinder service) {
			mBluetoothLeService = ((RBLService.LocalBinder) service)
					.getService();
			if (!mBluetoothLeService.initialize()) {
				Log.e(TAG, "Unable to initialize Bluetooth");
				finish();
			}

			// Automatically connects to the device upon successful start-up
			// initialization.
			mBluetoothLeService.connect(mDeviceAddress);
		}

		@Override
		public void onServiceDisconnected(ComponentName componentName) {

			mBluetoothLeService = null;
		}
	};

	private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
			final String action = intent.getAction();

			if (RBLService.ACTION_GATT_DISCONNECTED.equals(action)) {
				tv.setText("Ready..");
				bleState = 0;
			} else if (RBLService.ACTION_GATT_SERVICES_DISCOVERED
					.equals(action)) {
				getGattService(mBluetoothLeService.getSupportedGattService());
			} else if (RBLService.ACTION_DATA_AVAILABLE.equals(action)) {
				//Data Rx
				byte[] RxData = intent.getByteArrayExtra(RBLService.EXTRA_DATA);
				if(RxData[0] == 's'){
					tv.setText("Start!!");
					bleState = 1;
				}
			}
		}
	};

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

		tv = (TextView) findViewById(R.id.textView);

		//Joy Stick
		//https://github.com/clkasd/JoystickView
		jsv = (JoystickView)findViewById(R.id.joystickview);
		jsv.setJoystickChangeListener(new JoystickView.JoystickChangeListener() {
			@Override
			public void onJoystickChanged(int power, int degree) {
				Log.v("power", String.valueOf(String.valueOf(power)));
				Log.v("degree", String.valueOf(String.valueOf(degree)));
				sendJoyStick(power, degree);
			}
		});

		Intent intent = getIntent();

		mDeviceAddress = intent.getStringExtra(Device.EXTRA_DEVICE_ADDRESS);
		mDeviceName = intent.getStringExtra(Device.EXTRA_DEVICE_NAME);

		getActionBar().setTitle(mDeviceName);
		getActionBar().setDisplayHomeAsUpEnabled(true);

		Intent gattServiceIntent = new Intent(this, RBLService.class);
		bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);
	}

	@Override
	protected void onResume() {
		super.onResume();

		registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		if (item.getItemId() == android.R.id.home) {
			mBluetoothLeService.disconnect();
			mBluetoothLeService.close();

			System.exit(0);
		}

		return super.onOptionsItemSelected(item);
	}

	@Override
	protected void onStop() {
		super.onStop();

		unregisterReceiver(mGattUpdateReceiver);
	}

	@Override
	protected void onDestroy() {
		super.onDestroy();

		mBluetoothLeService.disconnect();
		mBluetoothLeService.close();

		System.exit(0);
	}

	private void getGattService(BluetoothGattService gattService) {
		if (gattService == null)
			return;

		BluetoothGattCharacteristic characteristic = gattService
				.getCharacteristic(RBLService.UUID_BLE_SHIELD_TX);
		map.put(characteristic.getUuid(), characteristic);

		BluetoothGattCharacteristic characteristicRx = gattService
				.getCharacteristic(RBLService.UUID_BLE_SHIELD_RX);
		mBluetoothLeService.setCharacteristicNotification(characteristicRx,
				true);
		mBluetoothLeService.readCharacteristic(characteristicRx);
	}

	private static IntentFilter makeGattUpdateIntentFilter() {
		final IntentFilter intentFilter = new IntentFilter();

		intentFilter.addAction(RBLService.ACTION_GATT_CONNECTED);
		intentFilter.addAction(RBLService.ACTION_GATT_DISCONNECTED);
		intentFilter.addAction(RBLService.ACTION_GATT_SERVICES_DISCOVERED);
		intentFilter.addAction(RBLService.ACTION_DATA_AVAILABLE);

		return intentFilter;
	}

	//Data Tx
	public void sendJoyStick(int pow, int deg){
		BluetoothGattCharacteristic characteristic = map
				.get(RBLService.UUID_BLE_SHIELD_TX);

		byte[] bytes = new byte[4];
		bytes[0]='c';
		bytes[1]=(byte)pow;
		bytes[2]=(byte)(Math.abs(deg)); //
		if(deg < 0){
			bytes[3] = 1; //
		}else{
			bytes[3] = 2; //
		}

		characteristic.setValue(bytes);

		if(bleState == 1){
			mBluetoothLeService.writeCharacteristic(characteristic);
		}
	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:weightSum="1">

    <TextView
        android:id="@+id/textView"
        android:layout_width="256dp"
        android:layout_height="50dp"
        android:scrollbars="vertical"
        android:textSize="30dp"
        android:text="Ready..." />

    <com.developwear.joystickview.JoystickView
        android:id="@+id/joystickview"
        android:layout_width="700px"
        android:layout_height="700px"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center_horizontal" />

</LinearLayout>

apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.hmg.moterdrive_blenano02"
        minSdkVersion 21
        targetSdkVersion 21
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile 'com.android.support:support-v4:21.0.0'
    compile 'com.developwear:joystickviewlib:1.0.1'
}