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The Matter bridge application demonstrates how to use the Matter application layer to build a bridge device.
You can use this application as a reference for creating your own application.
See the Matter Bridge page for more information about the Matter bridge specification and architecture.
A micro-USB cable for every development kit to connect it to the PC.
To commission the Matter bridge device and control it remotely through a Wi-Fi network, you also need a Matter controller device configured on PC or smartphone.
This requires additional hardware depending on your setup.
Note
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 application uses buttons to control the device state and a single LED to show the state of a device.
The Matter bridge has capability of representing non-Matter bridged devices as dynamic endpoints.
The application supports bridging the following Matter device types:
On/Off Light
On/Off Light Switch
Generic Switch
Temperature Sensor
Humidity Sensor
If the Matter device type required by your use case is not supported, you can extend the application.
For information about how to add a new bridged Matter device type to the application, see the Extending the application section.
Except for the On/Off Light Switch, all of the listed device types are enabled by default.
To disable one of them, set any of the following configuration options:
Additionally, you can choose to use the On/Off Light Switch implementation instead of the Generic Switch implementation for a switch device.
To enable the On/Off Light Switch implementation, set the following configuration options:
The application supports over-the-air (OTA) device firmware upgrade (DFU) using either of the two following protocols:
Matter OTA update protocol.
Querying and downloading a new firmware image is done using the Matter operational network.
Simple Management Protocol (SMP) over Bluetooth LE.
The DFU is done using either 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.
Matter OTA update protocol is enabled by default.
To configure the application to support the DFU over both Matter and SMP, use the -DCONFIG_CHIP_DFU_OVER_BT_SMP=y build flag.
When building on the command line, run the following command:
west build -b board_target -- dfu_build_flag
Replace board_target with the board target name of the hardware platform you are using (see Requirements), and dfu_build_flag with the desired DFU build flag.
For example:
west build -b nrf7002dk/nrf5340/cpuapp -- -DCONFIG_CHIP_DFU_OVER_BT_SMP=y
For information about how to upgrade the device firmware using a PC or a smartphone, see the Upgrading the device firmware section.
The application supports two bridged device configurations that are mutually exclusive:
Simulated bridged device - This configuration simulates the functionality of bridged devices by generating pseudorandom measurement results and changing the light state in fixed-time intervals.
Bluetooth LE bridged device - This configuration allows to connect a real peripheral Bluetooth LE device to the Matter bridge and represent its functionalities using Matter Data Model.
The application supports the following Bluetooth LE services:
Nordic Semiconductor’s LED Button Service - represented by the Matter On/Off Light and Generic Switch device types.
The service can be configured to use the On/Off Light Switch instead of the Generic Switch device type.
Zephyr’s Environmental Sensing Service - represented by the Matter Temperature Sensor and Humidity Sensor device types.
If the Bluetooth LE service required by your use case is not supported, you can extend the application.
For information about how to add a new Bluetooth LE service support to the application, see the Adding support for a new Bluetooth LE service section.
Depending on the bridged device you want to support in your application, enable it using the appropriate Kconfig option.
The Matter bridge supports adding and removing bridged devices dynamically at application runtime using Matter CLI commands from a dedicated Matter bridge shell module.
By default, the Matter accessory device has no IPv6 network configured.
To use the device within a Wi-Fi network, you must pair it with the Matter controller over Bluetooth® LE to get the configuration from the controller.
The Bluetooth LE advertising starts automatically upon device startup, but only for a predefined period of time (1 hour by default).
If the Bluetooth LE advertising times out, you can re-enable it manually by pressing Button (SW1).
Additionally, the controller must get the Onboarding information from the Matter accessory device and provision the device into the network.
For details, see the Testing section.
If the device is not provisioned to the Matter network, it initiates the SMP server (Simple Management Protocol) and Bluetooth LE advertising for Matter commissioning.
After that, the Device Firmware Update (DFU) over Bluetooth Low Energy can be started.
(See Upgrading the device firmware.)
Bluetooth LE advertising makes the device discoverable over Bluetooth LE for the predefined period of time (1 hour by default).
If the device is already provisioned to the Matter network, it re-enables the SMP server.
After that, the 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 a 3-second window of the initiation cancels the factory reset procedure.
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:
If the CONFIG_BRIDGED_DEVICE_BT Kconfig option is set to y, shows the current state of Bridge’s Bluetooth LE connectivity.
The following states are possible:
Turned Off - The Bridge device is in the idle state and has no Bluetooth LE devices paired.
Solid On - The Bridge device is in the idle state and all connections to the Bluetooth LE bridged devices are stable.
Slow Even Flashing (1000 ms on / 1000 ms off) - The Bridge device lost connection to at least one Bluetooth LE bridged device.
Even Flashing (300 ms on / 300 ms off) - The scan for Bluetooth LE devices is in progress.
Fast Even Flashing (100 ms on / 100 ms off) - The Bridge device is connecting to the Bluetooth LE device and waiting for the Bluetooth LE authentication PIN code.
SEGGER J-Link USB Port:
Used for getting logs from the device or for communicating with it through the command-line interface.
Adding a simulated bridged device to the Matter bridge
Use the following command:
matter_bridge add <device_type>["node_label"]
In this command:
<device_type> is the Matter device type to use for the bridged device.
The argument is mandatory and accepts the following values:
15 - Generic Switch.
256 - On/Off Light.
259 - On/Off Light Switch.
770 - Temperature Sensor.
775 - Humidity Sensor.
[“node label”] is the node label for the bridged device.
The argument is optional and you can use it to better personalize the device in your application.
Example command:
uart:~$ matter_bridgeadd256"Kitchen Light"
Controlling a simulated On/Off Light bridged device
Use the following command:
matter_bridge onoff <new_state><endpoint>
In this command:
<new_state> is the new state (0 - off and 1 - on) that will be set on the simulated On/Off Light device.
<endpoint> is the endpoint on which the bridged On/Off Light device is implemented
Example command:
uart:~$ matter_bridgeonoff13
Note that the above command will only work if the CONFIG_BRIDGED_DEVICE_SIMULATED_ONOFF_SHELL option is selected in the build configuration.
If the Kconfig option is not selected, the simulated device changes its state periodically in autonomous manner and cannot be controlled by using shell commands.
Controlling a simulated On/Off Light Switch bridged device
Use the following command:
matter_bridge onoff_switch <new_state><endpoint>
In this command:
<new_state> is the new state (0 - off and 1 - on) that will be set on the simulated On/Off Light Switch device.
<endpoint> is the endpoint on which the bridged On/Off Light Switch device is implemented
Example command:
uart:~$ matter_bridgeonoff_switch13
Adding a Bluetooth LE bridged device to the Matter bridge
<ble_device_index> is the Bluetooth LE device index on the list returned by the scan command.
The argument is mandatory and accepts only the values returned by the scan command.
[“node label”] is the node label for the bridged device.
The argument is optional and you can use it to better personalize the device in your application.
Example command:
uart:~$ matter_bridgeadd0"Kitchen Light"
The terminal output is similar to the following one:
----------------------------------------------------------------------------------------| Bridged Bluetooth LE device authentication || || Insert pin code displayed by the Bluetooth LE peripheral device || to authenticate the pairing operation. || || To do that, use matter_bridge pincode <ble_device_index> <pincode> shell command. |----------------------------------------------------------------------------------------
To complete the adding process, you must use the pincode command to insert the authentication pincode displayed by the bridged device.
<ble_device_index> is the Bluetooth LE device index on the list returned by the scan command.
<ble_pincode> is the Bluetooth LE authentication pincode of the bridged device to be paired.
Example command:
uart:~$ matter_bridgepincode0305051
The terminal output is similar to the following one:
I: Pairing completed: E3:9D:5E:51:AD:14 (random), bonded: 1I: Security changed: level 4I: The GATT discovery completedI: Added device to dynamic endpoint 3 (index=0)I: Added device to dynamic endpoint 4 (index=1)I: Created 0x100 device type on the endpoint 3I: Created 0xf device type on the endpoint 4
Removing a bridged device from the Matter bridge
Use the following command:
matter_bridge remove <bridged_device_endpoint_id>
In this command, <bridged_device_endpoint_id> is the endpoint ID of the bridged device to be removed.
Enable support for Humidity Sensor bridged device.
CONFIG_BRIDGE_ONOFF_LIGHT_BRIDGED_DEVICE
Enable support for OnOff Light bridged device.
CONFIG_BRIDGE_SWITCH_BRIDGED_DEVICE
Enable support for a switch bridged device.
Accepts the following values:
CONFIG_BRIDGE_GENERIC_SWITCH_BRIDGED_DEVICE
Enable support for Generic Switch bridged device.
CONFIG_BRIDGE_ONOFF_LIGHT_SWITCH_BRIDGED_DEVICE
Enable support for OnOff Light Switch bridged device.
CONFIG_BRIDGE_TEMPERATURE_SENSOR_BRIDGED_DEVICE
Enable support for Temperature Sensor bridged device.
If you selected the simulated device implementation using the CONFIG_BRIDGED_DEVICE_SIMULATED Kconfig option, also check and configure the following option:
Select the simulated OnOff device implementation.
Accepts the following values:
CONFIG_BRIDGED_DEVICE_SIMULATED_ONOFF_AUTOMATIC
Automatically simulated OnOff device.
The simulated device automatically changes its state periodically.
CONFIG_BRIDGED_DEVICE_SIMULATED_ONOFF_SHELL
Shell-controlled simulated OnOff device.
The state of the simulated device is changed using shell commands.
If you selected the Bluetooth LE device implementation using the CONFIG_BRIDGED_DEVICE_BT Kconfig option, also check and configure the following options:
CONFIG_BRIDGE_BT_MAX_SCANNED_DEVICES
Set the maximum number of scanned devices.
CONFIG_BRIDGE_BT_MINIMUM_SECURITY_LEVEL
Set the minimum Bluetooth security level of bridged devices that the bridge device will accept.
Bridged devices using this or a higher level will be allowed to connect to the bridge.
See the Configuring the Bluetooth LE security section for more information.
CONFIG_BRIDGE_BT_RECOVERY_MAX_INTERVAL
Set the maximum time (in seconds) between recovery attempts when the Bluetooth LE connection to the bridged device is lost.
CONFIG_BRIDGE_BT_RECOVERY_SCAN_TIMEOUT_MS
Set the time (in milliseconds) within which the Bridge will try to re-establish a connection to the lost Bluetooth LE device.
CONFIG_BRIDGE_BT_SCAN_TIMEOUT_MS
Set the Bluetooth LE scan timeout in milliseconds.
The following options affect how many bridged devices the application supports.
See the Bridged device configuration section for more information.
CONFIG_BRIDGE_MAX_BRIDGED_DEVICES_NUMBER
Set the maximum number of physical non-Matter devices supported by the Bridge.
CONFIG_BRIDGE_MAX_DYNAMIC_ENDPOINTS_NUMBER
Set the maximum number of dynamic endpoints supported by the Bridge.
The simulated On/Off Light bridged device can operate in the following modes:
Autonomous - The simulated device periodically changes its state.
To build the simulated On/Off Light data provider in this mode, select the CONFIG_BRIDGED_DEVICE_SIMULATED_ONOFF_AUTOMATIC Kconfig option.
Controllable - The user can explicitly control the On/Off state by using shell commands.
To build the simulated On/Off Light data provider in this mode, select the CONFIG_BRIDGED_DEVICE_SIMULATED_ONOFF_SHELL Kconfig option.
This is enabled by default.
Additionally, you can decide how many bridged devices the bridge application will support.
The decision will make an impact on the flash and RAM memory usage, and is verified in the compilation stage.
The application uses dynamic memory allocation and stores bridged device objects on the heap, so it may be necessary to increase the heap size using the CONFIG_CHIP_MALLOC_SYS_HEAP_SIZE Kconfig option.
Use the following configuration options to customize the number of supported bridged devices:
CONFIG_BRIDGE_MAX_DYNAMIC_ENDPOINTS_NUMBER - For changing the maximum number of Matter endpoints used for bridging devices by the bridge application.
This option does not have to be equal to CONFIG_BRIDGE_MAX_BRIDGED_DEVICES_NUMBER, as it is possible to use non-Matter devices that are represented using more than one Matter endpoint.
Configuring the number of Bluetooth LE bridged devices
You have to consider several factors to decide how many Bluetooth LE bridged devices to support.
Every Bluetooth LE bridged device uses a separate Bluetooth LE connection, so you need to consider the number of supported Bluetooth LE connections (selected using the CONFIG_BT_MAX_CONN Kconfig option) when you configure the number of devices.
Since the Matter stack uses one Bluetooth LE connection for commissioning, the maximum number of connections you can use for bridged devices is one less than is configured using the CONFIG_BT_MAX_CONN Kconfig option.
Increasing the number of Bluetooth LE connections affects the RAM usage on both the application and network cores.
The current maximum number of Bluetooth LE connections that can be selected using the default configuration is 10.
You can increase the number of Bluetooth LE connections if you decrease the size of the Bluetooth LE TX/RX buffers used by the Bluetooth controller, but this will decrease the communication throughput.
Build the target using the following command in the project directory to enable a configuration that increases the number of Bluetooth LE connections to 20 by decreasing the sizes of Bluetooth LE TX/RX buffers:
The application uses Bluetooth LE Security Manager Protocol (SMP) to provide secure connection between the Matter bridge and Bluetooth LE bridged devices.
Note
Do not confuse the Bluetooth LE Security Manager Protocol (SMP) abbreviation with the Bluetooth LE Simple Management Protocol that has the same abbreviation and is used for the Device Firmware Upgrade process.
The following security levels are defined by the Bluetooth LE specification:
Security Level 1 - supports communication without security.
Security Level 2 - supports AES-CMAC communication encryption, but does not require device authentication.
Security Level 3 - supports AES-CMAC communication encryption, requires device authentication and pairing.
Security Level 4 - supports ECDHE communication encryption, requires authentication and pairing.
To read more about the Bluetooth LE security implementation in Zephyr, see the Security section of the Stack Architecture page.
By default, the Matter bridge application has SMP enabled and supports security levels 2, 3 and 4.
You can disable the Bluetooth LE security mechanisms by setting the CONFIG_BT_SMP Kconfig option to n.
This is strongly not recommended, as it leads to unencrypted communication with bridged devices, which makes them vulnerable to the security attacks.
You can select the minimum security level required by the application.
When selected, the Matter bridge will require setting the selected minimum level from the connected Bluetooth LE bridged device.
If the bridged device supports also levels higher than the selected minimum, the devices may negotiate using the highest shared security level.
In case the bridged device does not support the minimum required level, the connection will be terminated.
To select the minimum security level, set the CONFIG_BRIDGE_BT_MINIMUM_SECURITY_LEVEL Kconfig option to 2, 3 or 4.
The Matter bridge application uses a prj.conf configuration file located in the application root directory for the default configuration.
It also provides additional files for different custom configurations.
When you build the application, you can select one of these configurations using the FILE_SUFFIX variable.
You can program a portion of the application code related to the nRF70 Series’ Wi-Fi firmware onto an external memory to free up space in the on-chip memory.
This option is available only when building for the nRF5340 DK with the nRF7002 EK shield attached.
To prepare an application to use this feature, you need to create additional MCUboot partitions.
To learn how to configure MCUboot partitions, see the Adding nRF70 Series firmware patch partitions guide.
To enable this feature for Matter, set the SB_CONFIG_WIFI_PATCHES_EXT_FLASH_STORE, SB_CONFIG_DFU_MULTI_IMAGE_PACKAGE_WIFI_FW_PATCH Kconfig options to y, and set the SB_CONFIG_MCUBOOT_UPDATEABLE_IMAGES Kconfig option to 3.
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.
Open a serial port connection to the kit using a terminal emulator that supports VT100/ANSI escape characters (for example, nRF Connect Serial Terminal).
See Testing and optimization for the required settings and steps.
Observe that the LED1 starts flashing (short flash on).
This means that the sample has automatically started the Bluetooth LE advertising.
Commission the device to the Matter network.
See Commissioning the device for more information.
During the commissioning process, write down the value for the bridge node ID.
This is going to be used in the next steps (<bridge_node_ID>).
Depending on the chosen bridged devices configuration, complete the steps in one of the following tabs:
Using the terminal emulator connected to the bridge, run the following Matter CLI command to add a new bridged device:
uart:~$ matter_bridge add <device_type>
The <device_type> is the value of the Matter device type that will be used to represent a new bridged device in the Matter Data Model.
See the description in Matter CLI commands for the list of supported values.
For example, if you want to add a new bridged device that will be exposed as an On/Off Light endpoint, use the following command:
uart:~$ matter_bridgeadd256
The terminal output is similar to the following one:
Write down the value for the bridged device dynamic endpoint ID.
This is going to be used in the next steps (<bridged_device_endpoint_ID>).
Use the CHIP Tool to read the value of an attribute from the bridged device endpoint.
For example, read the value of the on-off attribute from the onoff cluster using the following command:
Connect the development kit that is running the Bluetooth LE sample to the PC.
Open a serial port connection to the kit using a terminal emulator that supports VT100/ANSI escape characters (for example, nRF Connect Serial Terminal).
See Testing and optimization for the required settings and steps.
Using the terminal emulator connected to the bridge, run the following Matter CLI command to scan for available Bluetooth LE devices:
uart:~$ matter_bridgescan
The terminal output is similar to the following one, with an entry for each connected Bluetooth LE device:
The <bluetooth_device_index> is a Bluetooth LE device index that was scanned in the previous step.
For example, if you want to add a new Bluetooth LE bridged device with index 1, use the following command:
uart:~$ matter_bridgeadd1
The terminal output is similar to the following one:
Write down the authentication pincode value from the Bluetooth LE bridged device terminal.
The terminal output is similar to the following one:
PasskeyforFD:D6:53:EB:92:3A(random):350501
In the above example output, the displayed pincode value is 350501.
It will be used in the next steps as <bluetooth_authentication_pincode>.
Insert the authentication pincode of the bridged device in the Matter bridge terminal.
To insert the pincode, run the following Matter CLI command with <bluetooth_authentication_pincode> replaced by the value read in the previous step:
For the LED Button Service and the Environmental Sensor, two endpoints are created:
For the LED Button Service, one implements the On/Off Light device and the other implements the Generic Switch or On/Off Light Switch device.
For the Environmental Sensor, one implements the Temperature Sensor and the other implements the Humidity Sensor.
Write down the value for the bridged device dynamic endpoint ID.
This is going to be used in the next steps (<bridged_device_endpoint_ID>).
Use the CHIP Tool to read the value of an attribute from the bridged device endpoint.
For example, read the value of the on-off attribute from the onoff cluster using the following command:
If you are using the Generic Switch implementation, read the value of the current-position attribute from the switch cluster using the following command:
Note that the Generic Switch is implemented as a momentary switch.
This means that, in contrast to the latching switch, it remains switched on only as long as the physical button is pressed.
In case of the Environmental Sensor, the current temperature and humidity measurements forwarded by the Bluetooth LE Environmental Sensor can be read as follows:
To test the bridged device working as a client, you need to enable On/Off Light Switch device support (see matter_bridge_app_overview_).
The On/Off Light Switch device is capable of controlling the On/Off Light state of another device, such as the Matter Light Bulb sample working on an additional development kit.
After building this application and the Matter Light Bulb sample, and programming them to the development kits, complete the following steps to test the bridged device working as a client:
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.
Open a serial port connection to the kit using a terminal emulator that supports VT100/ANSI escape characters (for example, nRF Connect Serial Terminal).
See Testing and optimization for the required settings and steps.
If the devices were not erased during the programming, press and hold Button 1 on each device until the factory reset takes place.
Commission the devices to the Matter network.
See Commissioning the device for more information.
During the commissioning process, write down the values for the bridge node ID and the light bulb node ID.
These IDs are going to be used in the next steps (<bridge_node_ID> and <light_bulb_node_ID>, respectively).
Add a bridged light switch device.
Complete the following steps to use either a simulated or a Bluetooth LE device.
Using the terminal emulator connected to the bridge, run the following Matter CLI command to add a new bridged device:
uart:~$ matter_bridge add 259
The terminal output is similar to the following one:
The <bluetooth_device_index> is the Bluetooth LE device index that was scanned in the previous step.
For example, if you want to add a new Bluetooth LE bridged device with index 0, use the following command:
uart:~$ matter_bridgeadd0
The terminal output is similar to the following one:
Write down the value for the 0x103 bridged device dynamic endpoint ID.
This is going to be used in the next steps (<bridged_light_switch_endpoint_ID>).
Use the CHIP Tool (“Writing ACL to the accesscontrol cluster” section) to add proper ACL for the light bulb device.
Use the following command, with the <bridge_node_ID> and <light_bulb_node_ID> values from the commissioning step:
Complete the following steps depending on your configuration:
Using the terminal emulator connected to the bridge, turn on the LED 2 located on the bound light bulb device, by running the following Matter CLI command:
Using the terminal emulator connected to the bridge, turn off the LED 2 located on the bound light bulb device, by running the following Matter CLI command:
Before starting the commissioning to Matter procedure, ensure that there is no other Bluetooth LE connection established with the device.
To commission the device, go to the Testing Matter in the nRF Connect SDK page and complete the steps for the Matter network environment and the Matter controller you want to use.
After choosing the configuration, the guide walks you through the following steps:
Build and install the Matter controller.
Commission the device.
Send Matter commands that cover scenarios described in the Testing section.
When you start the commissioning procedure, the controller must get the onboarding information from the Matter accessory device.
The onboarding information representation depends on your commissioner setup.
For this application, you can use one of the following onboarding information formats to provide the commissioner with the data payload that includes the device discriminator and the setup PIN code:
