How to connect to Raspberry pi with an android app over bluetooth

Question

I\'m having trouble connecting my smartphone to my raspberry pi over bluetooth using an app.

My situation:

I\'m developing a bluetooth controlla

Answer 1

Quick answer

Similar to how you started out on this a bluetooth connection requires both device address and service UUID.

The device address (ex: 00:72:02:97:33:2C) can be obtained from paired devices (or by allowing for discovery), see Android example app for more on that.

The UUID (ex: 00001101-0000-1000-8000-00805F9B34FB) is typically defined on the server part where a Bluetooth service is running with a specific identifier.

Now if you want to avoid that last part and just want to communicate simple data you can rely on a default using the bluetooth serial port. From Android Bluetooth documentation:

Hint: If you are connecting to a Bluetooth serial board then try using the well-known SPP UUID 00001101-0000-1000-8000-00805F9B34FB. However if you are connecting to an Android peer then please generate your own unique UUID.

More information

Android Documentation & Sample code

The android sample BluetoothChat is a nice example on how to deal with 2 way communication between 2 android devices.

Android Bluetooth Documentation https://developer.android.com/guide/topics/connectivity/bluetooth.html

The Bluetooth Chat sample https://developer.android.com/samples/index.html. Note that you can check this project out by just selecting File > New > Sample Project and searching for Bluetooth Chat in Android Studio.

Bluetooth connection from Android to Raspberry Pi (Python & Android code)

Dealing with starting such a service on a raspberry pi can be found using this Python example: http://blog.davidvassallo.me/2014/05/11/android-linux-raspberry-pi-bluetooth-communication/. Just one of the many samples available online. This example includes Android code.

Using Default UUID for Serial Port (C++ code)

If you want to implement such a thing on the raspberry Pi using C++ code I can recommended the documentation from http://people.csail.mit.edu/albert/bluez-intro/x502.html.

That link has example code for both server and client. Since this is using RFCOMM spec and default serial port UUID there is no need to specify any UUID.

BlueTerm Android Open source App (Android code)

If you look into how to connect to this from android you will likely end up finding the BlueTerm android app. This is an open source app so you can find all sources at https://github.com/johnhowe/BlueTerm/tree/master/src/es/pymasde/blueterm. There you can find the UUID for this serial port service:

private static final UUID SerialPortServiceClass_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

The complete BluetoothSerialService class is a good way of managing a bluetooth connection including handling messages back to UI.