BLE keyboard or mouse as input

[kmatch98]

I’d like an example of how to receive input from an BLE keyboard or mouse as an input device. I see an example file here but it is commented out and mentions that it needs to be updated:

Adafruit_CircuitPython_BLE/examples/ble_hid_central.py

[kmatch98]

@dhalbert was kind enough to give some feedback on discord, I thought it would be useful to capture that here for future reference.

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danh: sorry, it looks like there's a lot more work to do in the original library to get this to work; this is a bigger job even for a simple demo than I thought

kmatch98: I spent some hours looking through the various libraries from the HID peripheral example thinking I could just do the reverse. But I didn’t see a clear way to get an input report from the keyboard, and no hooks in the HID keyboard code to read an input and decode. As I’m just learning about a lot of this, I wasn’t certain if it was just my own lack of knowledge or if some key bits were missing. Thanks for looking at this, and I guess I will just stay tuned. Thanks for confirming my suspicions. Should I leave the issue open?

As a temporary solution I can use the UART input with the Bluefruit app, but will be good to have the option of a standard BLE keyboard.

danh: yes, definitely. The way the BLE services are defined is not easy to understand, and we need to add some buffering on the report characteristic so we can have a FIFO for the NOTIFY data that's coming in. The hid.py code was written early on in a rewrite of the BLE library API, and it could use some revision and addition

kmatch98: Ok, I’ll stay tuned. Thanks again for your help and prompt response. As a newbie it’s helpful to get feedback before getting too frustrated with these kinds of hurdles.

[dglaude]

@dhalbert Two questions and a set of argument to have this working:

(A) Do you think that this example was ever working?

If I find the date when this example was created without comment, then matching CircuitPython Firmware on that date, for a board that existed, and with library of that date... would I be able to get key from a BLE keyboard?

(B) Do you think it is possible to make a new demo that work with current firmware and library state (or is something missing in the core/library to get there)?

(C) The argument

Beeing able to receive input from a BLE keyboard would be great.

Today with CircuitPython we can (1) Pretend to be a USB keyboard (2) Pretend to be a BLE keyboard

On the receiving side, we with a Trinked CoProcessor we can (3) have a USB host, that convert keycode to UART. (This is outside of CircuitPython but I made a FeatherWing with that).

So the missing thing is to be able to (4) have a BLE central that receive key from a BLE keyboard.

If we have that, it would become possible to create a mini CircuitPython computer, just with a CLUE and a BLE keyboard. See the cyberDÛCK project.

[kmatch98]

In looking a bit more at the gaps here and working to comprehend @dhalbert comments on the notes above and the weekly call yesterday, I discovered that the HID keyboard layout library and Keyboard library consists of only write functionality but a read function is absent. I think this may be why dan mentioned that there are no buffers present. So I am considering that maybe the Bluetooth code may not be the issue, but it may be a general absence of HID “Host” functionality to receive any data.

To look for example code that works for keyboard input, one good example is the Arduino Keyboard Controller and USB Host code. Maybe that could be emulated but in CircuitPython.

[street-grease-coder]

there is a now very popular esp32/arduino library for this- was there any progress on the example code here?

https://github.com/T-vK/ESP32-BLE-Mouse

[mmartinortiz]

there is a now very popular esp32/arduino library for this- was there any progress on the example code here?

https://github.com/T-vK/ESP32-BLE-Mouse

I arrived to this issue looking for a way to connect a keyboard to the Adafruit Feather nRF52840 Express via Bluetooth, so the keystrokes can be read and used by the nRF52840. The library you linked is to do the opposite: make the ESP32 behave as a Bluetooth keyboard/mouse.

[mmartinortiz]

@evaherrada is there any plan to implement this ticket? Is there anything the community can do to help? I'm more skilled at Python than at Micro controllers, but maybe I can do something.

[tannewt]

@mmartinortiz I'd suggest joining the Discord to help. https://adafru.it/discord I might try to do this today actually. It probably needs a feature I'm working on for the ESP32-S3

[rdagger]

@tannewt Did you make any progress on the code to read a BLE keyboard?

[tannewt]

@rdagger I haven't. I got distract by USB host and then we had a baby. My goal was to sort out HID with USB Host and then apply that to BLE as well.

[rdagger]

@tannewt congratulations! I was hoping to make a wireless keyboard adapter for my 1978 Bally astrocade game console.

[tannewt]

@tannewt congratulations! I was hoping to make a wireless keyboard adapter for my 1978 Bally astrocade game console.

That sounds like a neat project! I'll have to keep that in mind. I'll shoot to pick this back up with the USB host stuff.

[foxy82]

Checking if any progress has been made on this in the last 6 months?

I'm really interested in using an ESP32-C3 to connect to a bluetooth remote (Consumer Control device in HID language) so that I can transmit the key presses over wifi to a separate device (picow at the moment) that will then send them to a computer - essentially transmitting the Bluetooth device over wifi to increase it's range.

[tjshippy]

Here's an upvote on this topic. I am working on using a Clue to display the position of a mouse (X,Y) and read the click events. From all the docs I can find, the mouse and keyboard reports are very similar.
https://forums.adafruit.com/viewtopic.php?t=197856