My app works fine on android kitkat device but when I try it on marshmallow I can't receive bluetooth data (maybe I am not connecting to the bluetooth device also? I am not sure). It is NOT that I miss asking for permissions, I have fixed that some days ago when I couldn't even scan for devices, you can have a look here: Bluetooth LE can't find any device on android 6.0
There is a first activity where I ask for permission and scan the available bluetooth devices and when I select which device I want it moves to receive the data in the "Chat" activity (I tried requesting permission inside all activities but no result...), the important part of which follows:
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.
tv.setText("Bluetooth initialized");
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)) {
} else if (RBLService.ACTION_GATT_SERVICES_DISCOVERED
.equals(action)) {
tv.setText("Data are ready to be sent");
getGattService(mBluetoothLeService.getSupportedGattService());
} else if (RBLService.ACTION_DATA_AVAILABLE.equals(action)) {
displayData(intent.getByteArrayExtra(RBLService.EXTRA_DATA));
}
}
};
So, on android api 23 and more I make it until the text message "Bluetooth initialized" but then nothing happens. If I use an android kitkat device it correctly follows with the "Data are ready to be sent" message and lastly the displayData function is called which does the main job...
To help you I also post the RBLService.java code:
package com.redbear.chat;
import java.util.UUID;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
/**
* Service for managing connection and data communication with a GATT server
* hosted on a given Bluetooth LE device.
*/
public class RBLService extends Service {
private final static String TAG = RBLService.class.getSimpleName();
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private String mBluetoothDeviceAddress;
private BluetoothGatt mBluetoothGatt;
public final static String ACTION_GATT_CONNECTED = "ACTION_GATT_CONNECTED";
public final static String ACTION_GATT_DISCONNECTED = "ACTION_GATT_DISCONNECTED";
public final static String ACTION_GATT_SERVICES_DISCOVERED = "ACTION_GATT_SERVICES_DISCOVERED";
public final static String ACTION_GATT_RSSI = "ACTION_GATT_RSSI";
public final static String ACTION_DATA_AVAILABLE = "ACTION_DATA_AVAILABLE";
public final static String EXTRA_DATA = "EXTRA_DATA";
public final static UUID UUID_BLE_SHIELD_TX = UUID
.fromString(RBLGattAttributes.BLE_SHIELD_TX);
public final static UUID UUID_BLE_SHIELD_RX = UUID
.fromString(RBLGattAttributes.BLE_SHIELD_RX);
public final static UUID UUID_BLE_SHIELD_SERVICE = UUID
.fromString(RBLGattAttributes.BLE_SHIELD_SERVICE);
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status,
int newState) {
String intentAction;
if (newState == BluetoothProfile.STATE_CONNECTED) {
intentAction = ACTION_GATT_CONNECTED;
broadcastUpdate(intentAction);
Log.i(TAG, "Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:"
+ mBluetoothGatt.discoverServices());
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
intentAction = ACTION_GATT_DISCONNECTED;
Log.i(TAG, "Disconnected from GATT server.");
broadcastUpdate(intentAction);
}
}
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_GATT_RSSI, rssi);
} else {
Log.w(TAG, "onReadRemoteRssi received: " + status);
}
}
;
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
};
private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}
private void broadcastUpdate(final String action, int rssi) {
final Intent intent = new Intent(action);
intent.putExtra(EXTRA_DATA, String.valueOf(rssi));
sendBroadcast(intent);
}
private void broadcastUpdate(final String action,
final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
// This is special handling for the Heart Rate Measurement profile. Data
// parsing is
// carried out as per profile specifications:
// http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
if (UUID_BLE_SHIELD_RX.equals(characteristic.getUuid())) {
final byte[] rx = characteristic.getValue();
intent.putExtra(EXTRA_DATA, rx);
}
sendBroadcast(intent);
}
public class LocalBinder extends Binder {
RBLService getService() {
return RBLService.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
// After using a given device, you should make sure that
// BluetoothGatt.close() is called
// such that resources are cleaned up properly. In this particular
// example, close() is
// invoked when the UI is disconnected from the Service.
close();
return super.onUnbind(intent);
}
private final IBinder mBinder = new LocalBinder();
/**
* Initializes a reference to the local Bluetooth adapter.
*
* @return Return true if the initialization is successful.
*/
public boolean initialize() {
// For API level 18 and above, get a reference to BluetoothAdapter
// through
// BluetoothManager.
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
Log.e(TAG, "Unable to initialize BluetoothManager.");
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
return false;
}
return true;
}
/**
* Connects to the GATT server hosted on the Bluetooth LE device.
*
* @param address The device address of the destination device.
* @return Return true if the connection is initiated successfully. The
* connection result is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG,
"BluetoothAdapter not initialized or unspecified address.");
return false;
}
// Previously connected device. Try to reconnect.
if (mBluetoothDeviceAddress != null
&& address.equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
Log.d(TAG,
"Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter
.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the
// autoConnect
// parameter to false.
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
Log.d(TAG, "Trying to create a new connection.");
mBluetoothDeviceAddress = address;
return true;
}
/**
* Disconnects an existing connection or cancel a pending connection. The
* disconnection result is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.disconnect();
}
/**
* After using a given BLE device, the app must call this method to ensure
* resources are released properly.
*/
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
}
/**
* Request a read on a given {@code BluetoothGattCharacteristic}. The read
* result is reported asynchronously through the
* {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*
* @param characteristic The characteristic to read from.
*/
public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.readCharacteristic(characteristic);
}
public void readRssi() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.readRemoteRssi();
}
public void writeCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.writeCharacteristic(characteristic);
}
/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic Characteristic to act on.
* @param enabled If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(
BluetoothGattCharacteristic characteristic, boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
if (UUID_BLE_SHIELD_RX.equals(characteristic.getUuid())) {
BluetoothGattDescriptor descriptor = characteristic
.getDescriptor(UUID
.fromString(RBLGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
descriptor
.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mBluetoothGatt.writeDescriptor(descriptor);
}
}
/**
* Retrieves a list of supported GATT services on the connected device. This
* should be invoked only after {@code BluetoothGatt#discoverServices()}
* completes successfully.
*
* @return A {@code List} of supported services.
*/
public BluetoothGattService getSupportedGattService() {
if (mBluetoothGatt == null)
return null;
return mBluetoothGatt.getService(UUID_BLE_SHIELD_SERVICE);
}
}and the manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.redbear.chat"
android:versionCode="1"
android:versionName="1.0" >
<uses-feature
android:name="android.hardware.bluetooth_le"
android:required="true" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- Needed only if your app targets Android 5.0 (API level 21) or higher. -->
<uses-feature android:name="android.hardware.location.gps" />
<uses-feature android:name="android.hardware.location.network" />
<application
android:allowBackup="true"
android:icon="@drawable/redbear"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.redbear.chat.Main"
android:label="@string/app_name"
android:screenOrientation="portrait" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.redbear.chat.Chat"
android:screenOrientation="portrait"
android:windowSoftInputMode="stateHidden" >
</activity>
<activity
android:name=".Device"
android:theme="@android:style/Theme.Dialog" >
</activity>
<service
android:name="com.redbear.chat.RBLService"
android:enabled="true" />
</application>
</manifest>Ok, the problem was not exactly in the code. There is a bug, when you install app from android studio on marshmallow (and above?) it doesn't give or ask permission for storage. I had to set manually the permission on app and then it worked because part of the code was being blocked because of that...