Bluetooth: Host for nRF RPC Bluetooth Low Energy

The nRF RPC Host sample demonstrates the Bluetooth® Low Energy (LE) stack with the Remote procedure call library (nRF RPC) library that exposes the stack’s interface to another device or CPU using Remote Procedure Calls (RPC). On an nRF53 Series device, this sample is supposed to run on the network core and it provides the Bluetooth LE functionality for the application core.

Requirements

The sample supports the following development kit:

Hardware platforms

PCA

Board name

Board target

nRF5340 DK

PCA10095

nrf5340dk

nrf5340dk/nrf5340/cpunet

Overview

Note

Currently, only a subset of Zephyr’s Bluetooth APIs is available over Bluetooth nRF RPC. For more details about the limitations, see the API documentation of the Bluetooth nRF RPC library.

The host (network core) is running the full Bluetooth LE stack. It receives serialized function calls that it decodes and executes, then sends response data to the client (application core).

When the sample starts, it displays the welcome prompt “Starting nRF RPC bluetooth host”.

Building and running

You must program this sample to the nRF5340 network core.

This sample can be found under samples/bluetooth/rpc_host in the nRF Connect SDK folder structure.

To build the sample with Visual Studio Code, follow the steps listed on the How to build an application page in the nRF Connect for VS Code extension documentation. See Configuring and building an application for other building scenarios, Programming an application for programming steps, and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Debug build

To build the sample with a debugging configuration, use the -DEXTRA_CONF_FILE=overlay-debugging.conf' flag in your build.

See Providing CMake options for instructions on how to add this option to your build. For example, when building on the command line, enter the following command:

west build samples/bluetooth/rpc_host -- -DEXTRA_CONF_FILE=overlay-debugging.conf

Example build

The recommended way of building the nRF RPC Host sample is to use the multi-image feature of the build system, building the sample with the same Bluetooth configuration as the application core sample. In this way, the sample is built automatically as a child image when the CONFIG_BT_RPC_STACK option is enabled.

See Configuring and building an application for information about how to configure a sample.

  1. Build the sample with the same Bluetooth configuration as the application core sample. For more details, see: Bluetooth Low Energy Remote Procedure Call.

  2. Build the Bluetooth: Peripheral UART on the application core. This sample works out of the box and does not require configuration changes.

  3. In the Peripheral UART sample directory, run the following command:

    west build -b nrf5340dk/nrf5340/cpuapp -- -DCONFIG_BT_RPC_STACK=y
    

You can also build the Bluetooth: Peripheral HIDS mouse sample using the above command. This sample requires some additional configuration in the samples/bluetooth/peripheral_hids_mouse/child_image/rpc_host.conf file. You can take it as an example on how to create configuration for your own application.

Testing

After programming the example build to your development kit, complete the following steps to test it:

  1. Connect the dual core development kit to the computer using a USB cable. The development kit is assigned a COM port (Windows) or ttyACM device (Linux), which is visible in the Device Manager.

  2. Connect to the kit with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.

  3. Reset the development kit.

  4. Observe that the terminal connected to the network core displays “Starting nRF RPC Bluetooth host”.

  5. On the terminal connected to the application core, you can observe your Bluetooth application is running.

Dependencies

This sample uses the following nRF Connect SDK library:

It uses the following sdk-nrfxlib library: