nRF52840 Dongle as BLE Coprocessor Controlled by Another MCU over USB CDC ACM

[yogesh0]

Hello, 

I am using an nRF52840 Dongle with Zephyr and would like to use it as a BLE coprocessor that is controlled by another microcontroller over a USB CDC ACM interface.

The goal is for the nRF52840 to handle the complete BLE functionality internally (Host + Controller), while the external microcontroller sends simple commands over USB CDC ACM and receives responses/events.

Ideally, I am looking for something similar to an AT-command interface or another lightweight command-based API over USB.

Does Nordic provide any ready-made firmware, sample application, or reference implementation in nRF Connect SDK / Zephyr for this use case?

I noticed that Zephyr provides the Bluetooth Shell sample. Should I use Bluetooth Shell over USB CDC ACM as a command interface for an external microcontroller? 

[Turbo J]

There is the Bluetooth HCI over UART sample code. But I don't think there is sample code that uses AT style API.

[yogesh0]

No it exposes only controller hci interface. I would need to implement bluetooth host in external microcontroller which is not what I want. 

[Simonr]

Hi

We don't have ready-made firmware for something like this I'm afraid, but as you say, I think the Bluetooth shell sample could be a good starting point. 

Best regards,

Simon