BLE Service discovery working - next to check characteristics exist and subscribe to notifications from them.

app/src/main/java/uk/org/openseizuredetector/GattAttributes.java

@@ -0,0 +1,24 @@
+package uk.org.openseizuredetector;
+// Defines the servies and characteristics we need to subscribe to.
+import java.util.HashMap;
+
+public class GattAttributes {
+    private static HashMap<String, String> attributes = new HashMap();
+    public static String HEART_RATE_MEASUREMENT = "00002a37-0000-1000-8000-00805f9b34fb";
+    public static String CLIENT_CHARACTERISTIC_CONFIG = "00002902-0000-1000-8000-00805f9b34fb";
+
+
+    static {
+        // Sample Services.
+        attributes.put("0000180d-0000-1000-8000-00805f9b34fb", "Heart Rate Service");
+        attributes.put("0000180a-0000-1000-8000-00805f9b34fb", "Device Information Service");
+        // Sample Characteristics.
+        attributes.put("00002a37-0000-1000-8000-00805f9b34fb", "Heart Rate Measurement");
+        attributes.put("00002a29-0000-1000-8000-00805f9b34fb", "Manufacturer Name String");
+    }
+
+    public static String lookup(String uuid, String defaultName) {
+        String name = attributes.get(uuid);
+        return name == null ? defaultName : name;
+    }
+}

app/src/main/java/uk/org/openseizuredetector/SdDataSourceBLE.java

@@ -23,12 +23,23 @@
 */
 package uk.org.openseizuredetector;
 
+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.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.SharedPreferences;
+import android.os.Binder;
 import android.os.Handler;
+import android.os.IBinder;
 import android.preference.PreferenceManager;
 import android.text.format.Time;
 import android.util.Log;
@@ -40,18 +51,42 @@ import org.json.JSONObject;
 import org.jtransforms.fft.DoubleFFT_1D;
 
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Timer;
 import java.util.TimerTask;
+import java.util.UUID;
 
 
 /**
  * A data source that registers for BLE GATT notifications from a device and
  * waits to be notified of data being available. */
 public class SdDataSourceBLE extends SdDataSource {
-    private SdDataBroadcastReceiver mSdDataBroadcastReceiver;
-
-
     private String TAG = "SdDataSourceBLE";
+    private BluetoothManager mBluetoothManager;
+    private BluetoothAdapter mBluetoothAdapter;
+    private String mBluetoothDeviceAddress;
+    private BluetoothGatt mBluetoothGatt;
+    private int mConnectionState = STATE_DISCONNECTED;
+
+    private static final int STATE_DISCONNECTED = 0;
+    private static final int STATE_CONNECTING = 1;
+    private static final int STATE_CONNECTED = 2;
+
+    public final static String ACTION_GATT_CONNECTED =
+            "com.example.bluetooth.le.ACTION_GATT_CONNECTED";
+    public final static String ACTION_GATT_DISCONNECTED =
+            "com.example.bluetooth.le.ACTION_GATT_DISCONNECTED";
+    public final static String ACTION_GATT_SERVICES_DISCOVERED =
+            "com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED";
+    public final static String ACTION_DATA_AVAILABLE =
+            "com.example.bluetooth.le.ACTION_DATA_AVAILABLE";
+    public final static String EXTRA_DATA =
+            "com.example.bluetooth.le.EXTRA_DATA";
+
+    public final static UUID UUID_HEART_RATE_MEASUREMENT =
+            UUID.fromString(GattAttributes.HEART_RATE_MEASUREMENT);
+
 
 
     public SdDataSourceBLE(Context context, Handler handler,
@@ -79,6 +114,36 @@ public class SdDataSourceBLE extends SdDataSource {
             mContext.startActivity(intent);
         }
         Log.i(TAG,"mBLEDevice is "+mBleDeviceName+", Addr="+mBleDeviceAddr);
+
+
+        // Now we have selected a BLE Device, open the bluetooth adapter and connect to it.
+        if (mBluetoothManager == null) {
+            mBluetoothManager = (BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
+            if (mBluetoothManager == null) {
+                Log.e(TAG, "Unable to initialize BluetoothManager.");
+            }
+        }
+
+        mBluetoothAdapter = mBluetoothManager.getAdapter();
+        if (mBluetoothAdapter == null) {
+            Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
+        }
+
+        if (mBluetoothAdapter == null || mBleDeviceAddr == null) {
+            Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
+        }
+
+        final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(mBleDeviceAddr);
+        if (device == null) {
+            Log.w(TAG, "Device not found.  Unable to connect.");
+        }
+        // We want to directly connect to the device, so we are setting the autoConnect
+        // parameter to false.
+        mBluetoothGatt = device.connectGatt(mContext, false, mGattCallback);
+        Log.d(TAG, "Trying to create a new connection.");
+        mBluetoothDeviceAddress = mBleDeviceAddr;
+        mConnectionState = STATE_CONNECTING;
+
     }
 
     /**
@@ -87,6 +152,18 @@ public class SdDataSourceBLE extends SdDataSource {
     public void stop() {
         Log.i(TAG, "stop()");
         mUtil.writeToSysLogFile("SDDataSourceBLE.stop()");
+
+        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
+            Log.w(TAG, "BluetoothAdapter not initialized");
+            return;
+        }
+        mBluetoothGatt.disconnect();
+        if (mBluetoothGatt == null) {
+            return;
+        }
+        mBluetoothGatt.close();
+        mBluetoothGatt = null;
+
         super.stop();
     }
 
@@ -94,22 +171,161 @@ public class SdDataSourceBLE extends SdDataSource {
 
 
 
+    // Implements callback methods for GATT events that the app cares about.  For example,
+    // connection change and services discovered.
+    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;
+                mConnectionState = STATE_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());
 
-    public class SdDataBroadcastReceiver extends BroadcastReceiver {
+            } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
-        //private String TAG = "SdDataBroadcastReceiver";
+                intentAction = ACTION_GATT_DISCONNECTED;
+                mConnectionState = STATE_DISCONNECTED;
+                Log.i(TAG, "Disconnected from GATT server.");
+                broadcastUpdate(intentAction);
+            }
+        }
 
         @Override
-        public void onReceive(Context context, Intent intent) {
+        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
-            Log.v(TAG,"SdDataBroadcastReceiver.onReceive()");
+            if (status == BluetoothGatt.GATT_SUCCESS) {
-            String jsonStr = intent.getStringExtra("data");
+                Log.v(TAG,"Services discovered");
-            Log.v(TAG,"SdDataBroadcastReceiver.onReceive() - data="+jsonStr);
+                List<BluetoothGattService> serviceList = mBluetoothGatt.getServices();
-            updateFromJSON(jsonStr);
+                for (int i=0; i<serviceList.size(); i++) {
+                    String uuidStr = serviceList.get(i).getUuid().toString();
+                    Log.v(TAG,"Service "+ uuidStr);
+                    if (!GattAttributes.lookup(uuidStr,"None").equals( "None")) {
+                        Log.v(TAG,"Service Name="+GattAttributes.lookup(uuidStr,"None"));
+                    }
+                }
+                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);
+        mContext.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_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
+            int flag = characteristic.getProperties();
+            int format = -1;
+            if ((flag & 0x01) != 0) {
+                format = BluetoothGattCharacteristic.FORMAT_UINT16;
+                Log.d(TAG, "Heart rate format UINT16.");
+            } else {
+                format = BluetoothGattCharacteristic.FORMAT_UINT8;
+                Log.d(TAG, "Heart rate format UINT8.");
+            }
+            final int heartRate = characteristic.getIntValue(format, 1);
+            Log.d(TAG, String.format("Received heart rate: %d", heartRate));
+            intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
+        } else {
+            // For all other profiles, writes the data formatted in HEX.
+            final byte[] data = characteristic.getValue();
+            if (data != null && data.length > 0) {
+                final StringBuilder stringBuilder = new StringBuilder(data.length);
+                for(byte byteChar : data)
+                    stringBuilder.append(String.format("%02X ", byteChar));
+                intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
+            }
+        }
+        mContext.sendBroadcast(intent);
+    }
+
+
+
+    /**
+     * 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);
+    }
+
+    /**
+     * 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);
+
+        // This is specific to Heart Rate Measurement.
+        if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
+            BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
+                    UUID.fromString(GattAttributes.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 List<BluetoothGattService> getSupportedGattServices() {
+        if (mBluetoothGatt == null) return null;
+
+        return mBluetoothGatt.getServices();
+    }
+
+
 }
 
 
 
 
 
+
+
+
+