Matter nRF Connect Window Covering Example Application#

The nRF Connect Window Covering Example demonstrates how to remotely control a window shutter device. It uses buttons to test changing cover position and device states and LEDs to show the state of these changes. You can use this example as a reference for creating your own application.

Nordic Semiconductor logo nRF52840 DK

The example is based on Matter and Nordic Semiconductor’s nRF Connect SDK, and supports remote access and control of a simulated window shutter over a low-power, 802.15.4 Thread network.

The example behaves as a Matter accessory, that is a device that can be paired into an existing Matter network and can be controlled by this network.

Overview#

This example is running on the nRF Connect platform, which is based on Nordic Semiconductor’s nRF Connect SDK and Zephyr RTOS. Visit Matter’s nRF Connect platform overview to read more about the platform structure and dependencies.

The Matter device that runs the window shutter application is controlled by the Matter controller device over the Thread protocol. By default, the Matter accessory device has IPv6 networking disabled. You must pair it with the Matter controller over Bluetooth® LE to get the configuration from the controller to use the device within a Thread or Wi-Fi network. You have to make the device discoverable manually (for security reasons). See Bluetooth LE advertising to learn how to do this. The controller must get the commissioning information from the Matter accessory device and provision the device into the network.

You can test this application remotely over the Thread or the Wi-Fi protocol, which in either case requires more devices, including a Matter controller that you can configure either on a PC or a mobile device.

Bluetooth LE advertising#

In this example, to commission the device onto a Matter network, it must be discoverable over Bluetooth LE. For security reasons, you must start Bluetooth LE advertising manually after powering up the device by pressing Button 4.

Bluetooth LE rendezvous#

In this example, the commissioning procedure is done over Bluetooth LE between a Matter device and the Matter controller, where the controller has the commissioner role.

To start the rendezvous, the controller must get the commissioning information from the Matter device. The data payload is encoded within a QR code, printed to the UART console, and shared using an NFC tag. NFC tag emulation starts automatically when Bluetooth LE advertising is started and stays enabled until Bluetooth LE advertising timeout expires.

Thread provisioning#

Last part of the rendezvous procedure, the provisioning operation involves sending the Thread network credentials from the Matter controller to the Matter device. As a result, device is able to join the Thread network and communicate with other Thread devices in the network.

Device Firmware Upgrade#

The example supports over-the-air (OTA) device firmware upgrade (DFU) using the Matter OTA update, which is mandatory for Matter-compliant devices and enabled by default.

For this method, the MCUboot bootloader solution is used to replace the old firmware image with the new one.

Matter Over-the-Air Update#

The Matter over-the-air update distinguishes two types of nodes: OTA Provider and OTA Requestor.

An OTA Provider is a node that hosts a new firmware image and is able to respond on an OTA Requestor’s queries regarding availability of new firmware images or requests to start sending the update packages.

An OTA Requestor is a node that wants to download a new firmware image and sends requests to an OTA Provider to start the update process.

Simple Management Protocol#

Simple Management Protocol (SMP) is a basic transfer encoding that is used for device management purposes, including application image management. SMP supports using different transports, such as Bluetooth LE, UDP, or serial USB/UART.

In this example, the Matter device runs the SMP Server to download the application update image using the Bluetooth LE transport.

See the Building with Device Firmware Upgrade support section to learn how to enable SMP and use it for the DFU purpose in this example.

Bootloader#

MCUboot is a secure bootloader used for swapping firmware images of different versions and generating proper build output files that can be used in the device firmware upgrade process.

The bootloader solution requires an area of flash memory to swap application images during the firmware upgrade. Nordic Semiconductor devices use an external memory chip for this purpose. The memory chip communicates with the microcontroller through the QSPI bus.

See the Building with Device Firmware Upgrade support section to learn how to change MCUboot and flash configuration in this example.

Requirements#

The application requires a specific revision of the nRF Connect SDK to work correctly. See Setting up the environment for more information.

Supported devices#

The example supports building and running on the following devices:

Hardware platform

Build target

Platform image

nRF52840 DK

nrf52840dk_nrf52840

nRF52840 DKnRF52840 DK

nRF5340 DK

nrf5340dk_nrf5340_cpuapp

nRF5340 DKnRF5340 DK

Device UI#

This section lists the User Interface elements that you can use to control and monitor the state of the device. These correspond to PCB components on the platform image.

LED 1 shows the overall state of the device and its connectivity. The following states are possible:

  • Short Flash On (50 ms on/950 ms off) — The device is in the unprovisioned (unpaired) state and is waiting for a commissioning application to connect.

  • Rapid Even Flashing (100 ms on/100 ms off) — The device is in the unprovisioned state and a commissioning application is connected through Bluetooth LE.

  • Short Flash Off (950ms on/50ms off) — The device is fully provisioned, but does not yet have full connectivity for Thread or Wi-Fi network.

  • Solid On — The device is fully provisioned and has full Thread network and service connectivity.

LED 2 indicates the lift position of the shutter, which is represented by the brightness of the LED. The brightness level ranges from 0 to 255, where the switched off LED with brightness level 0 indicates a fully opened shutter (lifted) and 255 indicates a fully closed shutter (lowered).

LED 3 indicates the tilt position of the shutter, which is represented by the brightness of the LED. The brightness level ranges from 0 to 255, where the switched off LED with brightness level 0 indicates a fully opened shutter (tilted to a horizontal position) and 255 indicates a fully closed shutter (tilted to a vertical position).

Button 1 can be used for the following purposes:

  • Pressed for 6 s — Initiates the factory reset of the device. Releasing the button within the 6-second window cancels the factory reset procedure. LED 1 and LED 4 blink in unison when the factory reset procedure is initiated.

  • Pressed for less than 3 s — Initiates the OTA software update process. This feature is disabled by default, but can be enabled by following the Building with Device Firmware Upgrade support instruction.

Button 2 — Pressing the button once moves the shutter towards the open position by one step. Depending on the current movement mode, the button decreases the brightness of LED2 for the lift mode and LED3 for the tilt mode.

Button 3 — Pressing the button once moves the shutter towards the closed position by one step. Depending on the current movement mode, the button increases the brightness of LED2 for the lift mode and LED3 for the tilt mode.

Button 2 and Button 3 — Pressing both buttons at the same time toggles the shutter movement mode between lift and tilt. After each device reset, the mode is set to lift by default.

Note:

Completely opening and closing the shutter requires 20 button presses (steps). Each step takes approximately 200 ms to simulate the real shutter movement. The shutter position and LED brightness values are stored in non-volatile memory and are restored after every device reset. After the firmware update or factory reset both LEDs are switched off by default, which corresponds to the shutter being fully open, both lift-wise and tilt-wise.

Button 4 — Pressing the button once starts the NFC tag emulation and enables Bluetooth LE advertising for the predefined period of time (15 minutes by default).

SEGGER J-Link USB port can be used to get logs from the device or communicate with it using the command line interface.

NFC port with antenna attached can be used to start the rendezvous by providing the commissioning information from the Matter device in a data payload that can be shared using NFC.

Setting up the environment#

Before building the example, check out the Matter repository and sync submodules using the following command:

    $ git submodule update --init

The example requires a specific revision of the nRF Connect SDK. You can either install it along with the related tools directly on your system or use a Docker image that has the tools pre-installed.

If you are a macOS user, you won’t be able to use the Docker container to flash the application onto a Nordic development kit due to certain limitations of Docker for macOS. Use the native shell for building instead.

Using Docker container for setup#

To use the Docker container for setup, complete the following steps:

  1. If you do not have the nRF Connect SDK installed yet, create a directory for it by running the following command:

    $ mkdir ~/nrfconnect

  2. Download the latest version of the nRF Connect SDK Docker image by running the following command:

    $ docker pull nordicsemi/nrfconnect-chip

  3. Start Docker with the downloaded image by running the following command, customized to your needs as described below:

     $ docker run --rm -it -e RUNAS=$(id -u) -v ~/nrfconnect:/var/ncs -v ~/connectedhomeip:/var/chip \
     -v /dev/bus/usb:/dev/bus/usb --device-cgroup-rule "c 189:* rmw" nordicsemi/nrfconnect-chip

    In this command:

    • ~/nrfconnect can be replaced with an absolute path to the nRF Connect SDK source directory.

    • ~/connectedhomeip must be replaced with an absolute path to the CHIP source directory.

    • -v /dev/bus/usb:/dev/bus/usb –device-cgroup-rule “c 189: rmw”* parameters can be omitted if you are not planning to flash the example onto hardware. These parameters give the container access to USB devices connected to your computer such as the nRF52840 DK.

    • –rm can be omitted if you do not want the container to be auto-removed when you exit the container shell session.

    • -e RUNAS=$(id -u) is needed to start the container session as the current user instead of root.

  4. Update the nRF Connect SDK to the most recent supported revision, by running the following command:

     $ cd /var/chip
 $ python3 scripts/setup/nrfconnect/update_ncs.py --update

Now you can proceed with the Building instruction.

Using native shell for setup#

To use the native shell for setup, complete the following steps:

  1. Download and install the following additional software:

  2. If you do not have the nRF Connect SDK installed, follow the guide in the nRF Connect SDK documentation to install the latest stable nRF Connect SDK version. Since command-line tools will be used for building the example, installing SEGGER Embedded Studio is not required.

    If you have the SDK already installed, continue to the next step and update the nRF Connect SDK after initializing environment variables.

  3. Initialize environment variables referred to by the CHIP and the nRF Connect SDK build scripts. Replace nrfconnect-dir with the path to your nRF Connect SDK installation directory, and toolchain-dir with the path to GNU Arm Embedded Toolchain.

     $ source nrfconnect-dir/zephyr/zephyr-env.sh
 $ export ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb
 $ export GNUARMEMB_TOOLCHAIN_PATH=toolchain-dir

  4. Update the nRF Connect SDK to the most recent supported revision by running the following command (replace matter-dir with the path to Matter repository directory):

     $ cd matter-dir
 $ python3 scripts/setup/nrfconnect/update_ncs.py --update

Now you can proceed with the Building instruction.

Building#

Complete the following steps, regardless of the method used for setting up the environment:

  1. Navigate to the example’s directory:

    $ cd examples/window-app/nrfconnect

  2. Run the following command to build the example, with build-target replaced with the build target name of the Nordic Semiconductor’s kit you own, for example nrf52840dk_nrf52840:

     $ west build -b build-target

    You only need to specify the build target on the first build. See Requirements for the build target names of compatible kits.

The output zephyr.hex file will be available in the build/zephyr/ directory.

Removing build artifacts#

If you’re planning to build the example for a different kit or make changes to the configuration, remove all build artifacts before building. To do so, use the following command:

$ rm -r build

Building with release configuration#

To build the example with release configuration that disables the diagnostic features like logs and command-line interface, run the following command:

$ west build -b build-target -- -DCONF_FILE=prj_release.conf

Remember to replace build-target with the build target name of the Nordic Semiconductor’s kit you own.

Building with Device Firmware Upgrade support#

Support for DFU using Matter OTA is enabled by default.

To enable DFU over Bluetooth LE, run the following command with build-target replaced with the build target name of the Nordic Semiconductor kit you are using (for example nrf52840dk_nrf52840):

```
$ west build -b build-target -- -DCONFIG_CHIP_DFU_OVER_BT_SMP=y
```

To completely disable support for DFU, run the following command with build-target replaced with the build target name of the Nordic Semiconductor kit you are using (for example nrf52840dk_nrf52840):

$ west build -b build-target -- -DCONF_FILE=prj_no_dfu.conf

Note:

There are two types of Device Firmware Upgrade modes: single-image DFU and multi-image DFU. Single-image mode supports upgrading only one firmware image, the application image, and should be used for single-core nRF52840 DK devices. Multi-image mode allows to upgrade more firmware images and is suitable for upgrading the application core and network core firmware in two-core nRF5340 DK devices.

Changing bootloader configuration#

To change the default MCUboot configuration, edit the prj.conf file located in the child_image/mcuboot directory.

Make sure to keep the configuration consistent with changes made to the application configuration. This is necessary for the configuration to work, as the bootloader image is a separate application from the user application and it has its own configuration file.

Changing flash memory settings#

In the default configuration, the MCUboot uses the Partition Manager to configure flash partitions used for the bootloader application image slot purposes. You can change these settings by defining static partitions. This example uses this option to define using an external flash.

To modify the flash settings of your board (that is, your build-target, for example nrf52840dk_nrf52840), edit the pm_static_dfu.yml file located in the configuration/build-target/ directory.

Configuring the example#

The Zephyr ecosystem is based on Kconfig files and the settings can be modified using the menuconfig utility.

To open the menuconfig utility, run the following command from the example directory:

$ west build -b build-target -t menuconfig

Remember to replace build-target with the build target name of the Nordic Semiconductor’s kit you own.

Changes done with menuconfig will be lost if the build directory is deleted. To make them persistent, save the configuration options in the prj.conf file.

Example build types#

The example uses different configuration files depending on the supported features. Configuration files are provided for different build types and they are located in the application root directory.

The prj.conf file represents a debug build type. Other build types are covered by dedicated files with the build type added as a suffix to the prj part, as per the following list. For example, the release build type file name is prj_release.conf. If a board has other configuration files, for example associated with partition layout or child image configuration, these follow the same pattern.

Before you start testing the application, you can select one of the build types supported by the sample. This sample supports the following build types, depending on the selected board:

  • debug — Debug version of the application - can be used to enable additional features for verifying the application behavior, such as logs or command-line shell.

  • release — Release version of the application - can be used to enable only the necessary application functionalities to optimize its performance.

  • no_dfu — Debug version of the application without Device Firmware Upgrade feature support - can be used only for the nRF52840 DK and nRF5340 DK, as those platforms have DFU enabled by default.

For more information, see the Configuring nRF Connect SDK examples page.

Flashing and debugging#

To flash the application to the device, use the west tool and run the following command from the example directory:

    $ west flash --erase

If you have multiple development kits connected, west will prompt you to pick the correct one.

To debug the application on target, run the following command from the example directory:

    $ west debug

Testing the example#

Check the CLI tutorial to learn how to use command-line interface of the application.

Testing using Linux CHIPTool#

Read the CHIP Tool user guide to see how to use CHIP Tool for Linux or mac OS to commission and control the application within a Matter-enabled Thread network.

Testing using Android CHIPTool#

Read the Android commissioning guide to see how to use CHIPTool for Android smartphones to commission and control the application within a Matter-enabled Thread network.

Testing Device Firmware Upgrade#

Read the DFU tutorial to see how to upgrade your device firmware.