How to read the rssi value of multiple device at one time where I have connected?

Question

I am developing an application where I have to connect to Bluetooth device on Android 4.3.

I can connect to the BLE device and read the RSSI from the device by using BluetoothGatt.readRemoteRssi().

And I want to read the RSSI of multiple device at one time where I have connected But I only can read the RSSI of BLE device which the device I connected last time.

If there has two BLE device A and B. I connected to device A, and read RSSI from it. After I connected to device B, and I can read the RSSI from device B. But it doesn't read the RSSI of device A, it only read the RSSI from device B.

In Main.java , it list all the device where I have connected.

When I click the device which on the list, it transmit the device name and address to DeviceControl.java.

final Intent qintent = new Intent(this, DeviceControl.class);
        devicelist.setOnItemClickListener(new OnItemClickListener() {

                    @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                long arg3) {
            // TODO Auto-generated method stub
            HashMap<String, Object> select = (HashMap<String, Object>) devicelist.getItemAtPosition(arg2);
            String name = (String) select.get("name");
            String address = (String) select.get("address");
            qintent.putExtra(DeviceControl.EXTRAS_DEVICE_NAME, name);
            qintent.putExtra(DeviceControl.EXTRAS_DEVICE_ADDRESS, address);
            startActivity(qintent);
        }
    });

And the DeviceControl.java will call the BluetoothLeService.java and connect to device.

private final ServiceConnection mServiceConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName componentName, IBinder service) {
        // TODO Auto-generated method stub
        mBluetoothLeService = ((BluetoothLeService.LocalBinder) service).getService();
        if(!mBluetoothLeService.initialize()) {
            Log.e(TAG, "Unable to initialize Bluetooth");
            finish();
        }
        registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
        mBluetoothLeService.connect(mDeviceAddress);
    }
    @Override
    public void onServiceDisconnected(ComponentName componentName) {
        // TODO Auto-generated method stub
        mBluetoothLeService = null;
    }
};

And the BluetoothLeService.java will connect to the device.

public boolean connect(final String address) {
    if (mBluetoothAdapter == null || address == null) {
        Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
        return false;
    }
    if(mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress) 
            && mBluetoothGatt != null) {
        Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
        if(mBluetoothGatt.connect()) {
            mConnectionState = STATE_CONNECTING;                
            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;
    }
    mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
    Log.d(TAG, "Try to create a new connection");
    mBluetoothDeviceAddress = address;
    mConnectionState =STATE_CONNECTING;
    return true;
}

After it connect to the Device, I can use readRemoteRssi to read the RSSI from device.

public void readRemoteRssi() {
    mBluetoothGatt.readRemoteRssi();
}

But it only read the RSSI of the last one device that I have connected.

When I see the Log, it always send onCharacteristicWrite and readRemoteRssi() to the last one device that I have connected.

Should I reconnect GATT or reconnect device to the first address before I want to read the RSSI or write the CharacteristicWrite value to first device ??

Does it has other method to read the RSSI of all the device that I have connected ??

Answer 1

Make multiple BluetoothGatt object to connect multiple device separately, and call readRemoteRssi one by one.

Lazy and bad example, you should be able to put those BluetoothGatt object into an array

BluetoothGatt mBluetoothGatt1 = device1.connectGatt(this, false, mGattCallback);
BluetoothGatt mBluetoothGatt2 = device2.connectGatt(this, false, mGattCallback);