Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

blitz0145 — Fri, 14 Feb 2025 12:56:29 GMT

Hello Sigurd,
LLPM will solve the issue.

Thank you for your time!

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

Sigurd — Fri, 14 Feb 2025 11:41:29 GMT

Hi!

Gazell does not use MPSL. I suggest evaluating nRF Desktop.

Regarding latency, nRF Desktop have support for Low latency packet mode (LLPM)

Allows up to 1000 packets/second
1 ms connection interval (2 ms with two peripherals connected)

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

blitz0145 — Thu, 13 Feb 2025 12:01:33 GMT

That's great for an alternative!
However upon testing we figured that latency becomes a bit of an issue- I've roughly explained the problem here.

Theoretically Gazell would fix the latency issue between the keyboard and mouse if used correctly with the Multi Protocol Service Layer.

Also, if making Gazell work with MPSL is challenging, we're also willing to switch to an alternate protocol like ESB (Enhanced Shock Burst)

Here are a few resources:
https://github.com/inductivekickback/ncs_ble_esb_demo
The github link demonstrates how ESB can be modified to work with MPSL. Perhaps this could also be done with Gazell?

https://devzone.nordicsemi.com/guides/nrf-connect-sdk-guides/b/software/posts/updating-to-the-mpsl-timeslot-interface

We'll also have a 'dongle' mode- so that would look something like this:

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

Lorenzo Amicucci — Thu, 13 Feb 2025 07:45:31 GMT

Have you considered using BLE multirole? one device will be peripheral only. The other device will be central and peripheral. In this way the BT stack will handle connections without conflicts. (more difficult when you combine gazell with BLE concurrent as their timing may collide)

for HID, check also the nRF Desktop application. There is the code for the dongle and code for peripherals, all over BLE. There should be all building blocks for what you need, but it needs some code adjustments for sure. Basically you need to combine the dongle with the peripheral.

See block diagrams
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/applications/nrf_desktop/README.html

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

blitz0145 — Wed, 12 Feb 2025 17:32:52 GMT

The Gazell solution seems to be the most sound one. Perhaps there are some examples on how to get Gazell to work with MPSL?

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

blitz0145 — Wed, 12 Feb 2025 17:08:38 GMT

Hello!

[quote userid="15146" url="~/f/nordic-q-a/118863/making-separate-ble-mouse-keyboard-each-nrf52832-appear-as-a-single-ble-device/522655"]Could you explain why you have this goal?[/quote]

The mouse and keyboard are going to get shipped together as a pair; this eliminates the need to pair the mouse and keyboard individually to the desktop.

[quote userid="140946" url="~/f/nordic-q-a/118863/making-separate-ble-mouse-keyboard-each-nrf52832-appear-as-a-single-ble-device"]My goal is to make both devices appear as a single HID device when connected to a host (PC, Mac, etc.)[/quote]

Correcting my statement:
My goal is to make both devices appear as a single Bluetooth device when connected to a host.

RE: Making Separate BLE Mouse & Keyboard (each nRF52832) Appear as a Single BLE Device

Sigurd — Wed, 12 Feb 2025 13:30:53 GMT

Hi!

[quote user=""]My goal is to make both devices appear as a single HID device when connected to a host (PC, Mac, etc.).[/quote]

Could you explain why you have this goal?