How can i use the Bluetooth HID Device profile in Android Pie?

Question

I am trying to write an app for Android P using the Bluetooth HID device profile service to be used as a Bluetooth keyboard. According to the documentation I am supposed to use the method BluetoothAdapter.getProfileProxy(Context, BluetoothProfile.ServiceListener, int) to get the BluetoothHidDevice proxy object.

During debug on my Android Pie device (Nokia 7 plus) the service listener never get called (onServiceConnected), and i get the following error in Logcat:

Could not bind to Bluetooth HID Device Service with Intent { act=android.bluetooth.IBluetoothHidDevice }

If I change the last param in the call above from HID_DEVICE to some other bluetooth profile e.g. A2DP, the service listener get the callback onServiceConnected and no error is displayed.

1. Has anyone created a working HID_DEVICE on Android Pie?
2. Can BluetoothHidDevice be used to create a hid-device on an Android Pie phone?
3. Is there any working code that i can look at?
4. Is there some feature (getPackageManager().hasSystemFeature) missing in my phone?
5. What could be the reason for the error above?

Any hints would be greatly appreciated :)

This seems to be a third-party issue. Nokia did not enable the hid-profile in Android Pie. I also tried with a Mototorola G7 play, it was also disabled, i guess it's time for a pixel...

Answer 1

You can have a look at this https://github.com/kshoji/BLE-HID-Peripheral-for-Android . I was able to build a bluetooth keyboard out of this.

Answer 2

Currently on pixel the HID device Profile is enabled . Nokia, moto(as mentioned above) and One Plus 5T and 6 as far as i know dont support this profile.

We have created an app which lets you use your phone as a bluetooth mouse and keyboard with this HID device profile. https://play.google.com/store/apps/details?id=com.github.roarappstudio.btkontroller

The code is open sourced at https://github.com/raghavk92/Kontroller. If anyone wants to help in making improvements or contribute to the code they are welcome.

You can also check if your phone supports Bluetooth HID device profile with the app - https://play.google.com/store/apps/details?id=com.rkaneapplabs.bluetooth_hid.bluetoothproxy and let your device manufacturer know if they dont support your device because its part of android pie and should be supported.

Answer 3

There is a semi-official sample code available here: https://github.com/ginkage/wearmouse — actually by Google itself (see https://opensource.google.com/projects/wearmouse).

It is intended for using on Wear OS watches, but has everything you need to use it on a phone as well: proxy class for the profile, a callback class, HID Descriptor example, QoS, callbacks for cases like battery level inquiry from the host, etc.

The app itself is available at Google Play here: https://play.google.com/store/apps/details?id=com.ginkage.wearmouse (the app supports Android 8 as well, by the way, but that only works on watches, not phones).