Zigbee: Light switch
You can use the Zigbee Light switch sample to change the state of light sources on other devices within the same Zigbee network.
This sample supports the optional Sleepy End Device behavior and Multiprotocol Bluetooth LE extension. It also supports Zigbee FOTA. See Configuration files for sample extensions for details about how to enable these variants.
The sample supports the following development kits:
You can use one or more of the development kits listed above and mix different development kits.
To test this sample, you also need to program the following samples:
The Zigbee Network coordinator sample on one separate device.
The Zigbee: Light bulb sample on one or more separate devices.
The Light switch sample demonstrates the Zigbee End Device role and implements the Dimmer Switch device specification, as defined in the Zigbee Home Automation public application profile.
Once the light switch is successfully commissioned, it sends a broadcast message to find devices with the implemented Level Control and On/Off clusters. The light switch remembers the device network address from the first response. At this point, you can start using the buttons on the development kit to control the clusters on the newly found devices.
Additionally, the light switch sample powers down unused RAM sections to lower power consumption in the sleep state.
The light switch supports the Sleepy End Device behavior that enables the sleepy behavior for the end device, for a significant conservation of energy.
To enable the sleepy behavior, press Button 3 while the light switch sample is booting. This is required only when device is joining the network for the first time. After restarting the device, it will boot with the sleepy behavior enabled.
This optional extension demonstrates dynamic concurrent switching between two protocols, Bluetooth® LE and Zigbee. It uses the Nordic UART Service (NUS) library.
When this extension is enabled, you can use:
Buttons on the light switch device to operate on the Zigbee network
Nordic UART Service to operate on the Bluetooth LE network
Both networks are independent from each other.
To support both protocols at the same time, the Zigbee stack uses the IEEE 802.15.4 radio during the inactive time of the Bluetooth LE radio (using the Timeslot API of the Multiprotocol Service Layer). Depending on the Bluetooth LE connection interval, the nRF52 development kits can spend up to 99% of the radio time on the Zigbee protocol.
Transmitting and receiving data when using this example does not break connection from any of the used radio protocols, either Bluetooth LE or Zigbee.
For more information about the multiprotocol feature, see Multiprotocol support.
See Configuring and building an application for information about how to permanently or temporarily change the configuration.
This sample is split into the following source files:
mainfile to handle initialization and light switch basic behavior.
nus_cmdfile for handling NUS commands.
The sample provides predefined configuration files for optional extensions.
You can find the configuration files in the
Activating optional extensions
To activate the Zigbee FOTA, use the
prj_fota.conf configuration file.
For example, when building from the command line, use the following command:
west build samples/zigbee/light_switch -b nrf52840dk_nrf52840 -- -DCONF_FILE='prj_fota.conf'
Alternatively, you can configure Zigbee FOTA manually.
You can use the
prj_fota.conf file only with a development kit that contains the nRF52840 or nRF5340 SoC.
To activate the Multiprotocol Bluetooth LE extension, set OVERLAY_CONFIG to the
For example, when building from the command line, use the following command:
west build samples/zigbee/light_switch -b nrf52840dk_nrf52840 -- -DOVERLAY_CONFIG='overlay-multiprotocol_ble.conf'
For the board name to use instead of the
nrf52840dk_nrf52840, see Board names.
See Providing CMake options for instructions on how to add flags to your build. For more information about using configuration overlay files, see Important Build System Variables in the Zephyr documentation.
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, for example
SHIELD=nrf21540ek. This variable instructs the build system to append the appropriate devicetree overlay file.
To build the sample in the nRF Connect for VS Code IDE for an nRF52840 DK with the nRF21540 EK attached, add the shield variable in the build configuration’s Extra CMake arguments and rebuild the build configuration. For example:
See nRF Connect for VS Code extension pack documentation for more information.
To build the sample from the command line for an nRF52840 DK with the nRF21540 EK attached, use the following command within the sample directory:
west build -b nrf52840dk_nrf52840 -- -DSHIELD=nrf21540ek
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 3:
Lit and solid when the device is connected to a Zigbee network.
- LED 4:
Lit and solid when the light switch has found a light bulb to control.
- Button 1:
When the light bulb is turned off, turn it back on.
Pressing this button for a longer period of time increases the brightness of the light bulb.
- Button 2:
Turn off the light bulb connected to the network (light bulb’s LED 4). This option is available after the successful commissioning (light switch’s LED 3 turned on).
Pressing this button for a longer period of time decreases the brightness of the LED 4 of the connected light bulb.
- Button 4:
When pressed for five seconds, it initiates the factory reset of the device. The length of the button press can be edited using the
CONFIG_FACTORY_RESET_PRESS_TIME_SECONDSKconfig option from Zigbee application utilities. Releasing the button within this time does not trigger the factory reset procedure.
If the brightness level is at the minimum level, you may not notice the effect of turning on the light bulb.
- LED 2:
Indicates the OTA activity. Used only if the FOTA support is enabled.
- Button 3:
When pressed while resetting the kit, enables the Sleepy End Device behavior.
- LED 1:
Lit and solid when a Bluetooth LE Central is connected to the NUS service. Available when using Nordic UART Service (NUS) in the multiprotocol configuration.
- UART command assignments:
The following command assignments are configured and used in nRF Toolbox when Testing multiprotocol Bluetooth LE extension:
n- Turn on the Zigbee Light bulb.
f- Turn off the Zigbee Light bulb.
t- Toggle the Zigbee Light bulb on or off.
i- Increase the brightness level of the Zigbee Light bulb.
d- Decrease the brightness level of the Zigbee Light bulb.
If more than one light bulb is available in the network, these commands apply to all light bulbs in the network. See Testing multiprotocol Bluetooth LE extension for details.
Make sure to configure the Zigbee stack before building and testing this sample. See Configuring Zigbee in nRF Connect SDK for more information.
This sample can be found under
samples/zigbee/light_switch 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 for general information about testing and debugging in the nRF Connect SDK.
After programming the sample to your development kits, complete the following steps to test it:
Turn on the development kit that runs the Network coordinator sample.
When LED 3 turns on, this development kit has become the Coordinator of the Zigbee network.
Turn on the development kit that runs the Light bulb sample.
When LED 3 turns on, the light bulb has become a Router inside the network.
If LED 3 does not turn on, press Button 1 on the Coordinator to reopen the network.
Turn on the development kit that runs the Light switch sample.
When LED 3 turns on, the light switch has become an End Device, connected directly to the Coordinator.
Wait until LED 4 on the light switch node turns on.
This LED indicates that the light switch found a light bulb to control.
You can now use buttons on the development kit to control the light bulb, as described in User interface.
Testing multiprotocol Bluetooth LE extension
To test the multiprotocol Bluetooth LE extension, complete the following steps after the standard Testing procedure:
Set up nRF Toolbox by completing the following steps:
Tap UART to open the UART application in nRF Toolbox.
Configure the UART commands by completing the following steps:
Tap EDIT in the top right corner of the application. The button configuration window appears.
Create the active application buttons by completing the following steps:
ncommand to one of the buttons, with EOL set to LF and an icon of your choice.
fcommand to one of the buttons, with EOL set to LF and an icon of your choice.
tcommand to one of the buttons, with EOL set to LF and an icon of your choice.
dcommand to one of the buttons, with EOL set to LF and an icon of your choice.
icommand to one of the buttons, with EOL set to LF and an icon of your choice.
Tap DONE in the top right corner of the application.
Tap CONNECT and select the Zigbee_Switch device from the list of devices.
Observe that LED 1 on the light switch node is solid, which indicates that the Bluetooth LE connection is established.
In nRF Toolbox, tap the buttons you assigned:
Tap the n and f command buttons to turn the LED on the Zigbee Light bulb node on and off, respectively.
Tap the t command button two times to toggle the LED on the Zigbee Light bulb node on and off.
Tap the i and d command buttons to make adjustments to the brightness level.
You can now control the devices either with the buttons on the development kits or with the NUS UART command buttons in the nRF Toolbox application.
You can observe the sample logging output through a serial port after connecting with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.
This sample uses the following nRF Connect SDK libraries:
It uses the following sdk-nrfxlib libraries:
In addition, it uses the following Zephyr libraries:
The following dependencies are added by the multiprotocol Bluetooth LE extension: