从TI CC2540蓝牙低功耗套件接收数据

Question

I have a CC2540 BLE kit and i want to see the battery level of the kit in my smartphone app. I have made the code, which gets the battery level from the kit. The battery level is called BodySensor in this case:

First, i will go into the characteristic value of the battery service part for the kit. So i use the Service and Characteristic UUID's for the battery service:

public void getBodySensorLoc(BluetoothDevice device) 
{
    Log.i(TAG, "getBodySensorLoc");
    BluetoothGattService mHRP = mBluetoothGatt.getService(device, HRP_SERVICE);
    if (mHRP == null) 
    {
        Log.e(TAG, "getBodySensorLoc: mHRP = null");

        return;
    }
    BluetoothGattCharacteristic mBSLcharac = mHRP.getCharacteristic(BODY_SENSOR_LOCATION);
    if (mBSLcharac == null) {
        Log.e(TAG, "getBodySensorLoc: mBSLcharac = null");
        return;
    }
    mBluetoothGatt.readCharacteristic(mBSLcharac);
}

My purpose is to read the battery level, when pressing a button in my application. So i implement this button in my Activity class:

    ((Button) findViewById(R.id.btn_BSL)).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) 
        {
            mService.getBodySensorLoc(mDevice);
        }
    });

This kit will automatically send the battery level back to the smartphone. So i will set focus on onCharacteristicRead method of BluetoothGattCallback part in my code:

    private BluetoothGattCallback mGattCallbacks = new BluetoothGattCallback() 
{

    public void onCharacteristicRead(BluetoothGattCharacteristic charac, int status) 
    {
        UUID charUuid = charac.getUuid();
        Bundle mBundle = new Bundle();
        Message msg = Message.obtain(mActivityHandler, HRP_VALUE_MSG);
        Log.i(TAG, "onCharacteristicRead");
        if (charUuid.equals(BODY_SENSOR_LOCATION))
            mBundle.putByteArray(BSL_VALUE, charac.getValue());
        msg.setData(mBundle);
        msg.sendToTarget();
    }
};

I want the application to show the received battery level in a textview. The kit sends the battery level as a integer, so if the level is 70%, it sends "70". The code includes a Handler in the Activity class:

private Handler mHandler = new Handler() 
{
    @Override
    public void handleMessage(Message msg) 
    {
        switch (msg.what) 
        {
        case HRPService.HRP_VALUE_MSG:
            Log.d(TAG, "mHandler.HRP_VALUE_MSG");
            Bundle data1 = msg.getData();
            final byte[] bslval = data1.getByteArray(HRPService.BSL_VALUE);
            runOnUiThread(new Runnable() 
            {
                public void run() 
                {
                    if (bslval != null) 
                    {
                        try {
                            Log.i(TAG, "BYTE BSL VAL =" + bslval[0]);
                            TextView bsltv = (TextView) findViewById(R.id.BodySensorLocation);
                            bsltv.setText("\t" + mContext.getString(R.string.BodySensorLocation)
                                    + getBodySensorLocation(bslval[0]));
                        } catch (Exception e) 
                        {
                            Log.e(TAG, e.toString());

                        }

                    }
                }
            });

        default:
            super.handleMessage(msg);
        }
    }
};

The problem is that the textview doesn't show anything, when i press this button in my application after i connected my smartphone with the kit. Can anyone tell me, where the problem is ?.

Thanks in advance

Answer 1

Unsure what exact kit you have. Unsure if they all have battery level measuring hardware on board. Maybe this is the reason.