BlueUnity

BlueUnity is a plugin for using Bluetooth Serial with Unity3d on Android.

Installation

1. Create new Unity project.

2. Switch to Android build profile

3. In Player Settings -> Publishing Settings -> Build : enable Custom Main Manifest.

4. Also in Player Settings -> Other Settings -> Minimum API Level : set it to API level 27

5. Check in Player Settings -> Other Settings, if you have the option Application Entry Point, make sure to set it to Activity and not GameActivity as the plugin uses custom Android Manifest (Found that in Unity 6).

6. Import the latest UnityAndroidBluetooth Unitypackage . In the Scenes folder, you will find a scene "SampleScene" to test the Bluetooth plugin.

Note: Pluging was tested on Unity 2020.3.28f1 and Unity 6000.0.38f1 on a Samsung A53 that runs Android 14 (API 34) with a HC-05 bluetooth module.

Usage

1. Build the game using SampleScene or use the one I already built (see in 'Use this build to test/ V3').

2. Enable bluetooth and location.

3. Open the app and approve all permissions

4. Click Search button to start scanning for bluetooth devices or Paired Devices button to list all paired devices. Enter the MAC address of the bluetooth device, and click Start button to connect.

5. Enter data in the input field named "Enter Data to send" and click Send.

6. The incoming data is displayed directly on the screen, using ReadData(string data) which is called from Java class using UnityPlayer.UnitySendMessage().

Note: The plugin parses incoming data with inputBuffer.readLine(), which reads until it reaches a new line character ('\n').

8. To see Log messages, draw a circle in the screen with your finger to see the Log Viewer (Unity-Logs-Viewer from assets store).

9. Do not forget to enalbe bluetooth and location access.

Supported functionality

• Check and Request BT and location permissions (for Search Devices).
• Search Devices.
• Search Status.
• Get Paired Devices.
• Connect BT with MAC address.
• Disconnect BT.
• Connection Status.
• Read Stream.
• Write Stream.

I have Enhanced the code by using Unity3D UnityPlayer java class, this is done by adding the following line in build.gradle.kts of the Module, Here I'm using Unity 2020.3.28f1, change that to your version:

dependencies {
    ...
    compileOnly(files("C:/Program Files/Unity/Hub/Editor/2020.3.28f1/Editor/Data/PlaybackEngines/AndroidPlayer/Variations/mono/Release/Classes/classes.jar"))
    }

In the Java class you can import UnityPlayer java class:

import com.unity3d.player.UnityPlayer;

and use UnitySendMessage that searches for a GameObject by Name and calls a Function inside that GameObject and passes Arguments as String to it:

UnityPlayer.UnitySendMessage("GameObjectName", "FunctionToBeCalled", "ArgumentAsString");

This function is used for Search status, Connection status, New Device Found, and Read Data callbacks.

Demo and code explanation are coming soon, for now, I hope the code is self-explained.

Bluetooth Compatibility

BlueUnity was tested on HC-05, HC-06, BM78 Bluetooth modules, and ESP32 using the standard Bluetooth library (BluetoothSerial.h).

Note: Use println(data) or write(data+"\n"). As the plug-in expects new line ('\n') each time data is received.

Adapting to Your Project

If you want to edit the plugin and adapt it to your needs, check the "Android source code" folder, which contains the code of the plugin.

To create you own plug-in (the arr file), in Android studio go to File -> New -> New Module, and select Android Library.

To use UnitySendMessage don't forget to add the required dependency (check above) in 'build.gradle.kts' of your library

Contributing or Questions

Contact: [email protected]

License

MIT