Pairing with Gadgetbridge (Android emulator)

[vChavezB]

Since the posix build allows to test the firmware without hardware I am also trying to connect it to an Android Emulator :)

This is currently not possible with zephyr but I have submitted a PR to allow to have an HCI host (zephyr app) connect to an HCI controller (Android emulator) via a tcp server and a bridge between the tcp server and the android-netsim. See google/bumble#220

I am currently trying to connect to it with Android Emulator but the Gadgetbridge shows that the ZSwatch is not supported. Have you tried connecting the ZSwatch posix build with a real phone ? Perhaps due to my experimental setup I cannot test it with the Android Emulator.

[jakkra]

Wow, very cool! Yes it shows as unsupported, it's expected and I did not really bother to fix it as it still works. Long press it and select Bangle.js as the device and it should work.

This looks super useful!

[jakkra]

Very nice, now I can drop the dev kit I use as dongle, especially handy when working on a laptop.

The crashes can be in the ZSWatch software also maybe :p

I guess I need your patch to Zephy and then setting up the emulator, do you have a link how to set it up?

[vChavezB]

Yes, I like the idea of replacing all the hardware as much as possible 👍

Well for specific details you can check the workarounds I mentioned here. Basically I am using the experimental software Bumble to create a virtual hci bridge.

For the patch you can just replace the file zephyr/drivers/hci/user_chan.c with this one.

To connect to the Android emulator

1. Install bumble via pip install git+repo_url....
2. Install android emulator >=33.1.4.0 with a phone with SDK API 34. You can do this by installing the Android Studio preview. This is due to the fact that the bluetooth simulator is a recent feature.
3. Then create a device via Device Manager. Small Phone or Pixel 7 should work.
4. Im not sure about this but at least run once your device via terminal with emulator -avd YOUR_PHONE_API_34 -packet-streamer-endpoint default to enable the android-netsim.
5. Install your Bluetooth apps in the emulator. I recommend creating the Android device with support for google playstore in case an app is only available in the store. Otherwise use F-Droid.
6. Once the emulator is running run bumble bridge as follows
   bumble-hci-bridge tcp-server:_:9000 android-netsim 0x03:0x0031,0x03:0x035
7. Run the zephyr app with tcp server --bt-dev=127.0.0.1:9000
8. Profit

[jakkra]

Thanks for the instructions! Will give it a try tomorrow!

[vChavezB]

Just an update on my last post on this thread.

The changes I proposed to have a virtual bluetooth controller have been accepted and can now be tested directly in zephyr upstream 👍

[jakkra]

Very nice, still haven't gotten time to try it, but I plan do do that and write a proper guide so anyone can do that when developing. Right now working hard on final "2.0" HW, will be pretty cool, including the flash, light sensor and assembly at PCBway!