Silicon Labs Matter Version 2.9.1-1.6 (Aug 3, 2026) - Release Notes#
Simplicity SDK Version 2026.6.1
The Silicon Labs Matter v2.9.1-1.6 release provides the functionality to build Matter applications in the Simplicity Studio environment. This release is intended for developers who want to run Matter Demo over Thread (15.4) or Wi-Fi, and also manually build examples through Simplicity Studio v6 / Visual Studio Code or SLC-CLI.
This release is aligned with CSA Matter 1.6 for Thread (MG24, MG26, and MG30) and Wi‑Fi (SiWG917 and MG24 + SiWN917).
Release Summary#
Key Features | API Changes | Bug Fixes | Chip Enablement
Key Features#
Added in 2.9.1#
LLVM compiler support for Matter projects.
Added in 2.9.0#
Quality-tested Matter 1.6 solution for Thread and Wi-Fi.
Matter + AWS dual-stack support for 917 NCP boards.
API Changes#
None.
Bug Fixes#
See Bug Fixes.
Chip Enablement#
Added in 2.9.1#
None.
Added in 2.9.0#
Added support for late-arriving refresh boards: BRD4343C for Matter Wi-Fi SoC applications and BRD4357C for selected Matter Wi-Fi NCP applications. Silicon Labs has completed enablement and SQA validation for the supported application scope; customers should refer to the supported boards and application sections for exact coverage.
Key Features#
New Features | Enhancements | Removed Features | Deprecated Features
New Features#
Added in 2.9.1#
LLVM compiler support for Matter projects.
Added in 2.9.0#
Quality-tested Matter 1.6 solution for Thread MG24 / MG26 / MG30, Wi-Fi SiWG917 SoC and SiWN917 NCP mode.
Matter + AWS dual-stack support for 917 NCP boards.
Added LTO build support for SiWG917 sleepy and non-sleepy Matter Wi-Fi applications
Updated the GCC toolchain version to 14.2 release.
Enhancements#
Added in 2.9.1#
Added support for the new application architecture to the Fan Control, EVSE, Multi Sensor, Closure, Refrigerator, and Oven applications, simplifying future upgrades.
Added in 2.9.0#
Added new reworked Energy Management Clusters.
Updated the Lighting, Zigbee Matter Light, Lock, Light Switch, On-Off Plug, Thermostat, Range Hood, Platform Template, and Air Quality applications to use the new application architecture, simplifying future upgrades.
Removed Features#
Removed in 2.9.1#
None.
Removed in 2.9.0#
Removed Matter Wi-Fi support for MG24 + WF200.
Deprecated Features#
None.
API Changes#
New APIs | Modified APIs | Removed APIs | Deprecated APIs
New APIs#
None.
Modified APIs#
None.
Removed APIs#
None.
Deprecated APIs#
None.
Bug Fixes#
Fixed in 2.9.1#
ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
1617882 | Fixed: SiWx devices fail to commission with the latest updated firmware of amazon ecosystem | None | SiWx917 |
Fixed in 2.9.0#
ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
1571040, 1571039 | Fixed CSA test cases TC-RR-1.1 and TC-DESC-2.2 failing when run with the Windows app. | None | All |
1563443 | Fixed device boot failure for sleepy apps when built with LTO enabled. | None | SiWG917 |
1545117 | Fixed CSA test cases ACE 2.1 and ACE 2.2 failing when run with the test harness. | None | All |
1446745 | Fixed CSA test cases TC-WNCV failing when run with the Windows app. | None | SiWG917 |
1563537 | Fixed multi-sensor app to read temperature and humidity from the WPK sensor instead of logging identical values. | None | SiWG917 |
Chip Enablement#
None.
Matter over Thread is supported on the following boards#
MG24 boards:
BRD4186C / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@10dBm - xG24-RB4186C
BRD4187C / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@20dBm - xG24-RB4187C
BRD2601B / MG24 Developer Kit - xG24-DK2601B
BRD2703A / MG24 Explorer Kit - xG24-EK2703A
MGM24 boards:
BRD4316A / SLWSTK6006A / Wireless Start Kit / 2.4GHz@10dBm - xGM240-RB4316A
BRD4317A / SLWSTK6006A / Wireless Starter Kit/ 2.4GHz@20dBm - xGM240-RB4317A
BRD4318A / SLWSTK6006A / Wireless Starter Kit/ 2.4GHz@20dBm - xGM240-RB4318A
BRD4319A (Rev A00 only) / SLWSTK6006A / Wireless Starter Kit/ 2.4GHz@20dBm
BRD2704A / Sparkfun Thing Plus MGM240P
BRD4337A / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@20dBm - xGM240-RB4337A
MG26 boards
BRD4116A
BRD4117A
BRD4118A
BRD4120A
BRD4121A
BRD2608A
BRD2709A
MGM26 boards
BRD4350A
BRD4351A
MG30 Boards
BRD4407A
BRD4408A
BRD2719A
Matter over Wi-Fi is supported on the following boards#
SoC mode:
BRD4338A / SiWG917 Wi-Fi 6 and Bluetooth LE 8 MB Flash SoC Pro Kit - SiWx917-PK6031A
BRD2605A / SiWG917 Wi-Fi 6 and Bluetooth LE Dev Kit - SiWx917-DK2605A
BRD4342A / SiWG917 Wi-Fi 6 and Bluetooth LE 8 MB Flash + 8 MB ext PSRAM Radio Board with an internal RF switch - SiWx91x-RB4342A
BRD4343A / SiWG917Y Module Wi-Fi 6 and Bluetooth LE 8MB Flash RF-Pin Radio Board - SiW917Y-RB4343A
BRD4343C / SiWG917Y-X Module Wi-Fi 6 and Bluetooth LE 8MB Flash Antenna Radio Board - SiW917Y-RB4343C
BRD2708A / SiW917Y-EK2708A Module Wi-Fi 6 and Bluetooth LE Explorer kit - SiW917Y-EK2708A
NCP mode:
Host Processor:
BRD4186C / EFR32xG24 Wireless 2.4 GHz +10 dBm Radio Board (EFR32 radio board) - xG24-RB4186C
BRD4187C / EFR32xG24 Wireless 2.4 GHz +20 dBm Radio Board - xG24-RB4187C
Silicon Labs Wi-Fi Processor:
SiWx917-EB4346A - SiWx917 Wi-Fi 6 and Bluetooth LE Co-processor EXP Expansion Kit
SiW917Y-RB4357A - SiWN917Y Module Wi-Fi 6 and Bluetooth LE 4MB Flash RF-Pin Co-Processor Radio Board
SiW917Y-RB4357C - SiW917Y Module Wi-Fi 6 and Bluetooth LE 4MB Flash RF-Pin Co-Processor Radio Board
Note: Firmware for SiWN917 NCP, and SiWG917 SoC can be found in the Matter Software Artifacts page in the documentation or Assets section of this page. Connectivity firmware update is mandatory for new release binaries.
Application Example Changes#
New Examples | Modified Examples | Removed Examples | Deprecated Examples
For the list of supported application examples, see Existing Examples. For the details on Matter ecosystems support, see Ecosystems.
New Examples#
None.
Modified Examples#
The following examples have been refactored to support project upgrades from v2.9.1 onward by implementing CRTP architecture. For more information on refactoring effort, see Application Customization Models
Fan Control
EVSE
Multi-Sensor
Closure
Refrigerator
Oven
Removed Examples#
None.
Deprecated Examples#
Window Covering
Known Issues and Limitations#
ID | Issue or Limitation Description | GitHub / Salesforce Reference (if any) | Workaround (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|---|
The Matter logs are printed to the UART interface by default. To view the logs, use the Simplicity Studio console or a standalone terminal emulator such as PuTTY. The logging destination can be controlled by installing the "Logging To UART" or the "Logging to RTT" component under Matter -> Platform -> Utils in a Matter Studio project. | None | All | ||
The Matter device images require approximately 700 KB in flash space. As a result, only a subset of EFR32MG2x devices are supported. For a complete list of devices supported, see Matter Hardware Requirements. | None | All | ||
On Windows, Matter projects in Simplicity Studio may fail to build due to a known issue with GCC response files and the operating system's command string length limit. | None | When creating a new project, use shorter Solution and Project names and choose a shorter directory path for the project location. | All | |
A Matter SDK Issue: (https://github.com/project-chip/connectedhomeip). BLE Connection/Timeout error occurs occasionally during commissioning with the chip-tool running on Raspberry Pi or Linux (project-chip#16178). Running on these platforms requires an access point with both 2.4 GHz and 5 GHz capabilities. There is BLE-Wi-Fi interference when connected over the 2.4 GHz channel. | None | This is resolved by connecting the chip-tool device to a 5 GHz SSID and the end device to a 2.4 GHz SSID for the same Wi-Fi network. | All | |
In some rare cases, a Simplicity Studio project build may fail due to missing files in the | None | Delete the | All | |
1197733, 1228823 | Due to an electrical issue on the WPK main boards (BRD4002x), sometimes the current measurement value reported is wrong in the Energy Profiler, making it seem like an ICD is not going to sleep properly even though it is. This issue does not happen when using a WSTK (BRD4001x). | None | All | |
1416694 | The configuration parameters for the internal storage bootloader used in the OTA software updates must always be custom-configured based on the actual image size for the given application. See https://docs.silabs.com/matter/2.9.1/matter-ota/01-ota-bootloader. | None | All | |
1445664 | Chip-Cert executable cannot be used in Windows installations of Simplicity Studio v6. | None | All | |
Matter/Thread: Silicon Labs has provided a complete image file for the Raspberry Pi that can be flashed onto an SD card to create the Matter Hub, which is a Raspberry Pi running Ubuntu and includes a pre-built version of the Open Thread Border Router (OTBR) and chip-tool. The image we have provided is quite large, (approximately 2 GB). As a result, it can take quite a while to download the .zip file and flash it onto an SD card. Depending on your connection, the process could take up to half an hour. Regardless, the demo and development experiences using this pre-built image are a much faster process than building the Matter Hub from scratch. | None | EFR32 | ||
Matter/Thread: Matter attestation credentials can conflict with Lockbits in Series 2, requiring moving the location of the attestation credentials when lockbits are used. See Moving the Matter Attestation Credentials on Series 2 (MG24) for details. (1235425) | None | EFR32 | ||
1418676 | Possible race condition in UART driver when excessive use of the Matter shell is performed (sending commands every 250 ms). | None | Reduce the command rate. | EFR32 |
1453646 | Level attribute may get incorrectly changed on level-control stop. | None | EFR32 | |
Enabling "Logging to RTT" with SiWG917 SoC results in OTA update failure due to JLink connection preventing soft reset. | None | Enabled UART logging | SiWG917 | |
1366720 | BLE scan issues are observed with Raspberry Pi when the distance between the device and the controller exceeds 3 meters in highly congested environment. | None | None | SiWG917 |
1409219 | On the BRD2605A board, RGB LED pins are not configurable via the LED component or Pin Tool, requiring manual updates to the RTE device file for any new LED pin configurations. | None | Hardware limitation. | SiWG917 |
The external bootloader should not be used with the EFR32MG24+SiWN917 NCP device combination. Only use the internal bootloader. | None | None | SiWN917 | |
SiWN917 NCP application OTA upgrade with upgraded WiSeConnect SDK may not be backward compatible with the existing TA. | None | None | SiWN917 | |
Group commands only work for some specific access points when IGMP snooping is disabled. | None | None | All Wi-Fi boards | |
When setting up the Ozone Debugger on Mac, the location of the JLinkDevices.xml file has moved. Follow this documentation to place it in the proper location. | None | None | NA | |
1381843 | LCD is disabled on SiWN917 NCP. | None | LCD is disabled. | SiWN917 |
1563511 | Windows app not commissioning with the Apple Ecosystem. | Apple Ecosystem Issue | None | All |
1576627 | 917 sometimes fails to advertise BLE. | None | None | SiWx917 |
1388334 | On SiMG301x boards, the Zigbee Matter Light app may, in rare cases, briefly fail to receive Thread packets. This can lead to OTA update image transfer failures. | None | None | SiMG301x |
1680517 | Observed networking issue where Chiptool+OTBR running on a RasPi doesn't properly terminate the CASE session. The Matter accessory needs to time out before setting up a new CASE session with this controller | None | None | All |
1576808 | Observed networking issue where Chiptool+OTBR running on a RasPi has issue circulating mDNS messages | None | None | All |
1383892 | Matter thread cannot commission using the Amazon MSS | None | None | All |
1678551 | Observed increased power consumption for MG3x devices when HDR phy feature is enabled | None | None | SiMG301x |
1639061 | CSA test case TC-FAN-3.1 fails because the percentSettings is not being updated when the fanmode is changed | None | None | All |
1683431 | Enabling BLE Side Channel with Zigbee/Matter Light CMP concurrent application causes commissioning issues | None | None | EFR32 |
1738480 | Failed to Provision the SiWG917 Secure Board after masserasing the hardware | None | If the provisioning script fails after a mass erase, simply rerun the provisioning script. | SiWG917 |
1755826 | The Matter example fails to reset in Ozone IDE on Si917 Module boards (BRD4343A and BRD4343C) | None | None | SiWG917 |
Impact of Release Changes#
Impact Statements | Migration Guide
Impact Statements#
None.
Migration Guide#
sl_main migration: See sl_system to sl_main migration guide for detailed instructions.
Using This Release#
What's in the Release? | Compatible Software | Installation and Use | Help and Feedback
What's in the Release?#
Silicon Labs Matter Extension for use with Simplicity Studio and SLC-CLI.
Silicon Labs Matter sample applications.
Compatible Software#
Software | Compatible Version or Variant |
|---|---|
Simplicity SDK | |
WiSeConnect SDK | |
GCC (The GNU Compiler Collection) | 14.2.1 (provided with Simplicity Studio) |
Installation and Use#
To get started, download Simplicity Studio from the following link: https://www.silabs.com/developers/simplicity-studio, and install Simplicity SDK v2026.6.1 along with Silicon Labs Matter v2.9.1. For SiWx917, install WiSeConnect v4.1.1 as well.
Quick-start guides are provided for running pre-compiled demos and for building examples manually.
The Developer's Guide provides information on various technical topics.
For details on Studio project upgrades, see Project Upgrades.
In order to run Matter over Thread, a developer must have a Silicon Labs EFR-based device and either:
another EFR-based device and a Raspberry Pi with a 32 GB SD Card,
or an ecosystem device with OpenThread Border Router capabilities, such as Amazon Echo, Apple HomePod, Samsung SmartThings Hub or Google Nest Hub Wi-Fi.
In order to run Matter over Wi-Fi, a developer must have the following hardware:
Silicon Labs Wireless starter/development kit, which is mentioned below.
Raspberry Pi with a 32 GB SD Card or an ecosystem with Matter support
To run your first demo, see the Getting Started Guides.
To start your development, see the Developer's Guide.
For information about Secure Vault integration, see Secure Vault.
To review Security and Software Advisory notifications and manage your notification preferences:
Log in with your account credentials.
Click Profile icon in the upper-right corner of the page.
Select Notifications from the dropdown menu.
In the Notifications section, go to the My Product Notifications tab to review historical Security and Software Advisory notifications.
To manage your preferences, use the Manage Notifications tab to customize which product updates and advisories you receive.
To learn more about the software in this release, see the online documentation.
Help and Feedback#
Contact Silicon Labs Support.
Use the Ask AI tool to get answers, see the search field at the top of this page.
Get help from the developer community.
SDK Release and Maintenance Policy#
See SDK Release and Maintenance Policy.
Additional Information#
Existing Examples#
Matter over Thread is supported in Simplicity Studio for the following applications#
Lighting
Light Switch
Lock
Window Covering
Thermostat
OnOff Plug
Multi Sensor
Air Quality Sensor
Refrigerator
Zigbee/Matter CMP Lighting
Closure
Fan Control
Rangehood
Platform Template
EVSE
Matter over Wi-Fi is supported in Simplicity Studio for the following applications#
SoC and Dev Kit supported applications:
Lighting
Light Switch
Lock
Window Covering
Thermostat
OnOff Plug
Multi Sensor
Air Quality Sensor
Refrigerator
Closure
Fan Control
Rangehood
Oven
Platform Template
EVSE
NCP supported applications:
Lock
Thermostat
Window Covering
Matter over Wi-Fi ICD is supported for the following applications#
Lock (ICD is enabled by default)
With EFR32xG24 with SiWN917 in NCP mode
Window Covering (ICD is enabled by default)
With EFR32xG24 with SiWN917 in NCP mode
Thermostat
With EFR32xG24 with SiWN917 in NCP mode
Light Switch
With SiWG917 SoC
Reference guide to enable the sleepy functionality for Wi-Fi: Wi-Fi ICD.
Ecosystems#
This release has been tested and proven to work for commissioning and control with the following Ecosystems on the hardware and software versions listed below:
Google#
Silicon Labs Device | Application | Hub | Phone | App Software | Wi-Fi Access Point | |
|---|---|---|---|---|---|---|
Thread | BRD4187C | lighting/Lock/Window/Multi-sensor-app | Hardware: Google Nest Hub, Model : GUIK2 Software: Hub Software Version: Chromecast 3.78533433 | Hardware: Google Pixel 9A Software: Android version 16 | Google Home version: 4.18 | TPLink Archer AX73 |
Wi-Fi | BRD4338A | lighting/Lock/Window/Multi-sensor-app | Hardware: Google Nest Hub, Model : GUIK2 Software: Hub Software Version: Chromecast 3.78533433 | Hardware: Google Pixel 9A Software: Android version 16 | Google Home version: 4.18 | TPLink Archer AX73 |
Apple#
Silicon Labs Device | Application | Hub | Phone | App Software | Wi-Fi Access Point | |
|---|---|---|---|---|---|---|
Thread | BRD4187C | lighting/Lock/Window/Multi-sensor-app | Hardware: Home Pod MiniSoftware: (26.5 (26L471)) | Hardware: iPhone 14 pro Software: 26.5 | Apple Home 26.5 | TPLink Archer AX73 |
Wi-Fi | BRD4338A | lighting/Lock/Window/Multi-sensor-app | Hardware: Home Pod MiniSoftware: (26.5 (26L471)) | Hardware: iPhone 14 pro Software : 26.5 | Apple Home 26.5 | TPLink Archer AX73 |
Amazon#
Silicon Labs Device | Application | Hub | Phone | App Software | Wi-Fi Access Point | |
|---|---|---|---|---|---|---|
Thread | BRD4187C | lighting/lock/Window/Multi-sensor-app | Hardware: Echo 4th Gen Model: L4S3RE Software: Hub Software Version:12920396164 | Hardware: Google Pixel 9A Software: Android version 16 | Alexa version: 2.2.689582.0 | TPLink Archer AX73 |
Wi-Fi | BRD4338A | lighting/lock/Window/Multi-sensor-app | Hardware: Echo 4th Gen Model: L4S3RE Software: Hub Software Version:12920396164 | Hardware: Google Pixel 9A Software: Android version 16 | Alexa version: 2.2.689582.0 | TPLink Archer AX73 |
Samsung#
Silicon Labs Device | Application | Hub | Phone | App Software | Wi-Fi Access Point | |
|---|---|---|---|---|---|---|
Thread | BRD4187C | lighting/lock/Window/Multi-sensor-app | Hardware: SmartThings Station Software: Hub Software Version: 000.060.00012 | Hardware: Google Pixel 9A Software: Android version 16 | SmartThings Version: 1.8.45.24 | TPLink Archer AX73 |
Wi-Fi | BRD4338A | lighting/lock/Window/Multi-sensor-app | Hardware: SmartThings Station Software: Hub Software Version: 000.060.00012 | Hardware: Google Pixel 9A Software: Android version 16 | SmartThings Version: 1.8.45.24 | TPLink Archer AX73 |
Project Upgrades#
The following projects support automatic upgrades from version 2.9.0 to 2.9.1:
Air Quality
Lighting
Light Switch
Lock
Matter Platform Template
On-Off Plug
Range Hood
Thermostat
Zigbee Matter Light
Automatic upgrades from versions earlier than 2.9.0 are not supported.
Automatic upgrades from 2.9.0 to 2.9.1 are also not supported for the following projects:
Closure
EVSE
Fan Control
Multi Sensor
Oven
Refrigerator
To upgrade one of these projects to Matter Extension 2.9.1, follow these steps:
Create a new Matter Extension 2.9.1 project for the same application type, such as Fan Control or Closure.
For each file in the original project's
src/andinclude/directories that was modified, apply the same changes to the corresponding file in the new project.Replicate any nondefault component configurations from the original project in the new project.
Use the ZAP tool to replicate any additional cluster configurations from the original project.
Matter Software Artifacts#
Matter Software Artifacts: https://docs.silabs.com/matter/2.9.1/matter-prerequisites/matter-artifacts.