This blog is to describe how to compile and run the nRF5 HIDs Keyboard example from nRF Connect SDK.

nRF Connect SDK

The nRF Connect SDK is where you begin building low power wireless applications with Nordic Semiconductor nRF52, nRF53, and nRF91 Series devices.

The nRF Connect SDK is moved to https://github.com/nrfconnect instead of https://github.com/nordicplayground/nrfconnect. The folder of this github are shown as below.

Also, all the latest documentation can be found at https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/index.html.

Check the West Version

Upgrade west if need

Upgrade some dependence modules such as nrfutil

Create the folder of the ncs_keyboard

Checkout the master branch with West

To check out the latest state of development, enter the command:

Enter the following command to clone the project repositories:

west update

After do the west update, you can check the version of each.

If you need to get the particular tag release, you can use the git to check

For example, I plan to use the v1.3.0-rc1 on the NCS.

git checkout v1.3.0-rc1
cd ..
west update

nRF Desktop

The nRF Desktop is a reference design of a Human Interface Device (HID) that is connected to a host through Bluetooth LE or USB, or both. Depending on the configuration, this application can work as desktop mouse, gaming mouse, keyboard, or connection dongle.

The nRF Desktop application supports common input hardware interfaces like motion sensors, rotation sensors, and buttons scanning module. The firmware can be configured at runtime using a dedicated configuration channel established with the HID feature report.
The same channel is used to transmit DFU packets.

Overview: Firmware architecture

The nRF Desktop application design aims at high performance, while still providing configurability and extensibility.

The application architecture is modular and event-driven.
This means that parts of the application functionality are separated into isolated modules that communicate with each other using application events, which are handled by the event_manager.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/nrf_desktop/README.html


Modules register themselves as listeners of those events that they are configured to react to.
An application event can be submitted by multiple modules and it can have multiple listeners.

See the following subsections for more information about the firmware architecture:

Module usage per hardware type

Since the application architecture is uniform and the code is shared, the set of modules in use depends on the selected device role. A different set of modules is enabled when the application is working as mouse, keyboard, or dongle:

Memory Usage

All the examples are based on the 1.3.0-rc1.

nrf52dmouse_nrf52832

nrf52kbd_nrf52832

nrf52840gmouse_nrf52840

nrf52840dk_nrf52840

nrf52840dongle_nrf52840

Selecting nRF Desktop build types

Before you start testing the application, you can select one of the nRF Desktop build types, depending on your development kit and building method.

To select the build type in SEGGER Embedded Studio:

  1. Go to Tools -> Options… -> nRF Connect.
  2. Set Additional CMake Options to -DCMAKE_BUILD_TYPE=selected_build_type. For example, for ZRelease set the following value: -DCMAKE_BUILD_TYPE=ZRelease.
  3. Reload the project.

The changes will be applied after reloading.

Selecting a build type from command line

To select the build type when building the application from command line, specify the build type by adding the -- -DCMAKE_BUILD_TYPE=selected_build_type to the west build command.

For example, you can build the ZRelease firmware for the PCA20041 board by running the following command in the project directory:

west build -b nrf52840_pca20041 -d build_pca20041 -- -DCMAKE_BUILD_TYPE=ZRelease

The build_pca20041 parameter specifies the output directory for the build files.

NRF52840 Keyboard with Bootloader B0 (release version)

Bootloader

The nRF Desktop application uses Secure Bootloader, referred in this documentation as B0.

B0 is a small, simple, and secure bootloader that allows the application to boot directly from one of the application slots, thus increasing the speed of the direct firmware upgrade (DFU) process. More information about the B0 can be found at the Immutable bootloader page.

Enabling the bootloader

To enable the B0 bootloader, select the CONFIG_SECURE_BOOT Kconfig option. If this option is not selected, the application will be built without the B0 bootloader, and the background DFU will not be available.

Required options

The B0 bootloader requires the following options enabled:

For example, nrf52840dk_nrf52840 has the build type with bootloader.

How to generate the dfu_application.zip (dfu package)

http://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/scripts/hid_configurator/README.html#nrf-desktop-config-channel-script

Prepare the python applications (configuration channel) for DFU

Requirements

To use the HID configurator, you must set up the required Dependencies. Complete the following instructions, depending on your operating system:

Windows

Complete the following steps:

  1. Download the HIDAPI library from HIDAPI releases. Use the bundled DLL or build it according to instructions in HIDAPI library.
  2. Install pyhidapi Python wrapper with the following command:
py -3 -m pip install -r requirements.txt

Copy the hidapi.lib and hidapi.dll inside the folder nrf\scripts\hid_configurator

Download the pre-release of the pyAudio module

Check on the python version first

download PyAudio‑0.2.11‑cp37‑cp37‑win_amd64.whl from here on my computer in C:\Downloads\PyAudio-0.2.11-cp38-cp38-win32.whl (because I am using the python 3.7.3 in this example)

https://www.lfd.uci.edu/~gohlke/pythonlibs/#pyaudio