Circuitpython: nrf: implement BLE HID

[dhalbert]

[tannewt]

why is USB in the title?

[dhalbert]

why indeed?

[RoganDawes]

Is there any intention to implement this? I'd love to be able to implement a keyboard/mouse composite device in CircuitPython!

[dhalbert]

Yes, it is high on the list of features to implement next.

[jscholes]

Do you have any sort of ideas as to a timeline on this, or where it fits in on the roadmap. This would be super helpful for a project we're currently working on. If we were to write a Python extension in C, would we have access to the Arduino BLE libraries to implement BLE HID from that route? Or would it need to be done from scratch.

[dhalbert]

Good timing: I have been working on this today. The code is really all in Python: the C BLE modules provide the infrastructure. The HID-specific part of the code is relatively complex because of the complexity of HID. It needs pairing and bonding: I have pairing working, but have not yet implemented bonding (remembering the pairing info so you don't need to re-pair).

No promises on when it will get done, but it's my current task!

[jscholes]

Seriously fantastic news. Are you developing this on a public branch or repo? Would love to check it out and maybe help if you're looking for outside contributions. Thanks!

[klardotsh]

Consider me onboard to help as needed with this effort - BLE has been on KMK Firmware's goal list for about as long as the project has existed and we're finally stable enough in the core firmware to dedicate cycles to QoL/creature comfort features. If there's a way I/we can help, holler at us here/Discord/etc. Cheers!

[tannewt]

FYI CircuitPython works as a BLE peripheral with the latest CircuitPython master and the BLE library master. Here is the demo code: https://github.com/adafruit/Adafruit_CircuitPython_BLE/blob/master/examples/ble_hid_periph.py

I'll leave this open because I intend on supporting other BLE HID devices from CircuitPython as well.

[urish]

Any idea if this works with Windows / OSX hosts?

[dhalbert]

Any idea if this works with Windows / OSX hosts?

It should work fine assuming they have BLE support (you may need Windows 10). In our experience, iOS is the pickiest, and hardest to get working. Windows, MacOS, Linux, and Android are all easier, and we got them all to work.

[urish]

Thanks Dan! I'll give it a go with Windows 10!

[urish]

Windows 10 does see the device (even though not always - I had to remove the scan_response part from the advertising so that it show it on the list of pairable devices), but disconnects about one second after pairing with a "Driver error" message:

Android works well

[mscosti]

@urish I'm seeing the same thing as you. At first I thought this was related to changes I have made in an attempt to implement a different HID device incorrectly / missing something (Microsoft Radial Controller / Surface Dial) , But after seeing your report I loaded up this BLE HID Keyboard example verbatim and am seeing the same behavior on Windows 10. Same thing, where it takes a second or two for it to settle with "Driver error".

Android Recognizes the keyboard and am able to type on it as expected

[dhalbert]

I have been working on BLE bonding over the past couple of weeks (see #2510), and just tested on Windows 10 with a BLE-capable dongle, and did not have this problem. But it also worked before without bonding. So it may be particular to the Bluetooth hardware on your Windows machine(s).@mscosti and @urish, what is your hardware?

[mscosti]

@dhalbert I'm using a MS Surfacebook 2, which has Bluetooth built in (no dongle)

[dhalbert]

@mscosti hmm, some kind of pairing issue mentioned here: https://social.technet.microsoft.com/Forums/en-US/31e39461-0b8b-4daa-86d0-010f0bd2feed/microsoft-surface-and-ble-issue?forum=win10itprohardware. The OP said it works with a dongle, but not with the builtin Bluetooth hardware. I assume you're up to date on drivers and the latest version of Windows 10, but if not, that might be worth trying.

I did not find many similar reports, but very few people are trying to use BLE HID with Windows. It was only fairly recently it started to be better supported.

[mscosti]

The issue mentioned here sounds very similiar to the one I'm experiencing. https://answers.microsoft.com/en-us/windows/forum/all/problem-with-bluetooth-low-energy-gatt-compliant/ec845657-d885-47e8-a796-cd3ff83a7698

Unfortunately, the suggested solution that others confirmed working for them (uninstalling Microsoft Bluetooth LE Enumerator and restarting) did not seem to work for me. @urish , I am curious if this works for you, though.

I'm not sure if its relevant/true/meaningful, but when I look at the device in device manager / HID -> Bluetooth Low Energy Gatt compliant HID device, it says error code 10 in status like in the reported issue above, and the first response says

According to the error code, the cause of the issue: the device's hardware key contains a "FailReasonString" value, and the value string is displays an error message defined by the hardware manufacturer. If the hardware key does not contain a “FailReasonString” value the message above is displayed.

As far as I can tell i'm up to date on my drivers. I have 2 other Bluetooth HID devices (Pen digitizer, granted its a MS device), and a PS4 game pad, both of which are able to pair and function just fine.

[dhalbert]

According to the error code, the cause of the issue: the device's hardware key contains a "FailReasonString" value, and the value string is displays an error message defined by the hardware manufacturer. If the hardware key does not contain a “FailReasonString” value the message above is displayed.

I think that is just saying that it's failing and we didn't supply a reason string ??

As far as I can tell i'm up to date on my drivers. I have 2 other Bluetooth HID devices (Pen digitizer, granted its a MS device), and a PS4 game pad, both of which are able to pair and function just fine.

Are those other devices BLE or classic Bluetooth (it might be hard to tell from the specs)?

[mscosti]

hmm. Not sure about the PS4 game pad, I think that's older, but the Surface Pen is listed as using Bluetooth 4.0, and in device manager shows up in HID section as Bluetooth Low Energy GATT compliant HID. So, still not 100% sure, but most likely?

Is there perhaps some arduino BLE HID code I could try on the CPB instead to see if I get the same issue?

[dhalbert]

How about https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/libraries/Bluefruit52Lib/examples/Peripheral/hid_keyboard/hid_keyboard.ino ? You'll need to install the Adafruit nRF52 BSP if you haven't already.

[mcosti]

Someone summoned me, lol

[dhalbert]

@mcosti: Sorry, typo for "mscosti" :)

[mscosti]

@dhalbert Thanks, I'll give that a shot when I next have time, likely sometime tomorrow evening. Is it appropriate/relevant to keep this discussion on this issue, or would you prefer a new github issue?

[dhalbert]

I've opened a new issue for the Windows problems.: #2517. Closing this because we do now have BLE HID.