Matter: Door lock
This door lock sample demonstrates the usage of the Matter application layer to build a door lock device with one basic bolt. This device works as a Matter accessory device, meaning it can be paired and controlled remotely over a Matter network built on top of a low-power 802.15.4 Thread network. Additionally, this device works as a Thread Router. You can use this sample as a reference for creating your application.
The sample supports the following development kits:
If you want to commission the lock device and control it remotely through a Thread network, you also need a Matter controller device configured on PC or mobile. This requires additional hardware depending on the setup you choose.
Matter requires the GN tool. If you are updating from the nRF Connect SDK version earlier than v1.5.0, see the GN installation instructions.
The sample uses buttons for changing the lock and device states, and LEDs to show the state of these changes. You can test it in the following ways:
Standalone, using a single DK that runs the door lock application.
Remotely over the Thread protocol, which requires more devices.
The remote control testing requires a Matter controller that you can configure either on a PC or a mobile device (for remote testing in a network). You can enable both methods after building and running the sample.
By default, the Matter accessory device has Thread 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 network. You have to make the device discoverable manually (for security reasons). The controller must get the commissioning information from the Matter accessory device and provision the device into the network. For details, see the Commissioning the device section.
Alternatively to the commissioning procedure, you can use the test mode that allows joining the Thread network with default static parameters and static cryptographic keys. Use Button 3 to enable this mode after building and running the sample.
The test mode is not compliant with Matter and it only works together with the Matter controller and other devices that use the same default configuration.
See Configuring your application for information about how to permanently or temporarily change the configuration.
The sample 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.
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
If a board has other configuration files, for example associated with partition layout or child image configuration, these follow the same pattern.
CONF_FILE variable contains a single file and this file follows the naming pattern
prj_<buildtype>.conf, then the build type will be inferred to be <buildtype>.
The build type cannot be set explicitly.
The <buildtype> can be any string, but it is common to use
For information about how to set variables, see Important Build System Variables in the Zephyr documentation.
The Partition Manager’s static configuration can also be made dependent on the build type.
When the build type has been inferred, the file
pm_static_<buildtype>.yml will have precedence over
The child image Kconfig configuration can also be made dependent on the build type.
The child image Kconfig file is named
<child_image>.conf instead of
prj.conf, but otherwise follows the same pattern as the parent Kconfig.
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 for the nRF52840 DK, nRF5340 DK and nRF21540 DK.
Selecting a build type is optional.
debug build type is used by default if no build type is explicitly selected.
You can enable over-the-air Device Firmware Upgrade only on hardware platforms that have external flash memory. Currently only nRF52840 DK and nRF5340 DK support Device Firmware Upgrade feature.
The sample supports over-the-air (OTA) device firmware upgrade (DFU) using one of the two following protocols:
Matter OTA update protocol that uses the Matter operational network for querying and downloading a new firmware image.
Simple Management Protocol (SMP) over Bluetooth® LE. In this case, the DFU can be done either using a smartphone application or a PC command line tool. Note that this protocol is not part of the Matter specification.
In both cases, MCUboot secure bootloader is used to apply the new firmware image.
The DFU over Matter is enabled by default.
To configure the sample to support the DFU over Matter and SMP, use the
-DCONFIG_CHIP_DFU_OVER_BT_SMP=y build flag during the build process.
To configure the sample to disable the DFU and the secure bootloader, use the
-DCONF_FILE=prj_no_dfu.conf build flag during the build process.
See Providing CMake options for instructions on how to add these options to your build.
When building on the command line, run the following command with build_target replaced with the build target name of the hardware platform you are using (see Requirements), and dfu_build_flag replaced with the desired DFU build flag:
west build -b build_target -- dfu_build_flag
You can add support for the nRF21540 front-end module to this sample by using one of the following options, depending on your hardware:
Build the sample for one board that contains the nRF21540 FEM, such as nrf21540dk_nrf52840.
Manually create a devicetree overlay file that describes how FEM is connected to the nRF5 SoC in your device. See Set devicetree overlays for different ways of adding the overlay file.
Provide nRF21540 FEM capabilities by using a shield, for example the nRF21540 EK shield that is available in the nRF Connect SDK. In this case, build the project for a board connected to the shield you are using with an appropriate variable included in the build command. This variable instructs the build system to append the appropriate devicetree overlay file. For example, to build the sample from the command line for an nRF52833 DK with the nRF21540 EK attached, use the following command within the sample directory:
west build -b nrf52833dk_nrf52833 -- -DSHIELD=nrf21540_ek
This command builds the application firmware. See Programming nRF21540 EK for information about how to program when you are using a board with a network core, for example nRF5340 DK.
Each of these options adds the description of the nRF21540 FEM to the devicetree. See Working with RF front-end modules for more information about FEM in the nRF Connect SDK.
To add support for other front-end modules, add the respective devicetree file entries to the board devicetree file or the devicetree overlay file.
- 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 over Bluetooth LE.
Solid On - The device is fully provisioned.
- LED 2:
Shows the state of the lock. The following states are possible:
Solid On - The bolt is extended and the door is locked.
Off - The bolt is retracted and the door is unlocked.
Rapid Even Flashing (50 ms on/50 ms off during 2 s) - The simulated bolt is in motion from one position to another.
- Button 1:
Depending on how long you press the button:
If pressed for less than three seconds, it initiates the SMP server (Security Manager Protocol). After that the Direct Firmware Update (DFU) over Bluetooth Low Energy can be started. (See Upgrading the device firmware.)
If pressed for more than three seconds, it initiates the factory reset of the device. Releasing the button within the 3-second window cancels the factory reset procedure.
- Button 2:
Changes the lock state to the opposite one.
- Button 3:
Starts the Thread networking in the test mode using the default configuration.
- Button 4:
Starts the NFC tag emulation, enables Bluetooth LE advertising for the predefined period of time (15 minutes by default), and makes the device discoverable over Bluetooth LE. This button is used during the commissioning procedure.
- SEGGER J-Link USB port:
Used for getting logs from the device or for communicating with it through the command-line interface.
- NFC port with antenna attached:
Optionally used for obtaining the commissioning information from the Matter accessory device to start the commissioning procedure.
This sample can be found under
samples/matter/lock in the nRF Connect SDK folder structure.
See Building and programming an application for information about how to build and program the application and Testing and debugging an application for general information about testing and debugging in the nRF Connect SDK.
See Configuration for information about building the sample with the DFU support.
Before you start testing the application, you can select one of the Matter door lock build types, depending on your building method.
Selecting a build type in Visual Studio Code
To select the build type in the nRF Connect for VS Code extension:
When Building an application as described in the nRF Connect for VS Code extension documentation, follow the steps for setting up the build configuration.
In the Add Build Configuration screen, select the desired
.conffile from the Configuration drop-down menu.
Fill in other configuration options, if applicable, and click Build Configuration.
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 following parameter to the
west build command:
For example, you can replace the selected_build_type variable to build the
release firmware for
nrf52840dk_nrf52840 by running the following command in the project directory:
west build -b nrf52840dk_nrf52840 -d build_nrf52840dk_nrf52840 -- -DCONF_FILE=prj_release.conf
build_nrf52840dk_nrf52840 parameter specifies the output directory for the build files.
If the selected board does not support the selected build type, the build is interrupted.
For example, if the
shell build type is not supported by the selected board, the following notification appears:
File not found: ./ncs/nrf/samples/matter/lock/configuration/nrf52840dk_nrf52840/prj_shell.conf
After building the sample and programming it to your development kit, complete the following steps to test its basic features:
Connect the kit to the computer using a USB cable. The kit is assigned a COM port (Windows) or ttyACM device (Linux), which is visible in the Device Manager.
Connect to the kit with a terminal emulator that supports VT100/ANSI escape characters (for example, PuTTY). See How to connect with PuTTY for the required settings.
Observe that LED 2 is lit, which means that the door lock is closed.
Press Button 2 to unlock the door. LED 2 is blinking while the lock is opening. After approximately two seconds, LED 2 turns off permanently. The following messages appear on the console:
I: Unlock Action has been initiated I: Unlock Action has been completed
Press Button 2 one more time to lock the door again. LED 2 starts blinking and remains turned on. The following messages appear on the console:
I: Lock Action has been initiated I: Lock Action has been completed
Press Button 1 to initiate factory reset of the device.
The device reboots after all its settings are erased.
Remote control allows you to control the Matter door lock device from a Thread network.
Use one of the following to enable remote control:
Commissioning the device allows you to set up a testing environment and remotely control the sample over a Matter-enabled Thread network.
Remote testing using test mode allows you to test the sample functionalities in a Thread network with default parameters, without commissioning. Use Button 3 to enable this mode after building and running the sample.
Commissioning the device
To commission the device, go to the Configuring Matter development environment guide and complete the steps for the Matter controller you want to use. The guide walks you through the following steps:
Configure the Thread Border Router.
Build and install the Matter controller.
Commission the device.
Send Matter commands that cover scenarios described in the Testing section.
If you are new to Matter, the recommended approach is to use CHIP Tool for Linux or macOS.
To upgrade the device firmware, complete the steps listed for the selected method in the Performing Device Firmware Upgrade in the nRF Connect examples tutorial of the Matter documentation.
This sample uses the Matter library that includes the nRF Connect SDK platform integration layer:
In addition, the sample uses the following nRF Connect SDK components:
The sample depends on the following Zephyr libraries: