Connect Version 4.1.0 (June 16, 2025) - Release Notes#
Simplicity SDK Version 2025.6.0
The Connect SDK is a complete software development suite for proprietary wireless applications that was previously part of the Proprietary SDK. Starting with the Connect SDK 4.0.0 release, Proprietary SDK is split into RAIL SDK and Connect SDK.
Connect SDK uses Silicon Labs Connect, an IEEE 802.15.4-based networking stack designed for customizable broad-based proprietary wireless networking solutions that require low power consumption and operate in either the sub-GHz or 2.4 GHz frequency bands. The solution is targeted towards simple network topologies.
Connect SDK is supplied with extensive documentation and sample applications. All examples are provided in source code within the Connect SDK sample applications.
Release Summary#
Key Features | API Changes | Bug Fixes | Chip Enablement
Key Features#
Added Connect RAIL DMP component to support custom proprietary communication next to the Connect network. This component is able to handle additional stacks, for example a setup with Connect-BLE-RAIL DMP.
Connect Stack and SDK was updated to use new RAIL 2.19.0 APIs.
API Changes#
None.
Bug Fixes#
emberAfStackStatusCallback()was not called if application is RTOS.RAIL Assert codes was missing from Connect Assert.
Chip Enablement#
EFRxG29
Key Features#
New Features | Enhancements | Removed Features | Deprecated Features
New Features#
Added Connect RAIL DMP component to support custom proprietary communication next to Connect network, component is able to handle additional stack like a setup with Connect-BLE-RAIL DMP.
Connect Stack and SDK was updated to use new RAIL 2.19.0 APIs.
Enhancements#
Updated sample applications to use sl_main instead of sl_system. main.c
is now provided by platform with improved optimization.
Removed Features#
None.
Deprecated Features#
None.
API Changes#
New APIs#
New API Signature | Deprecated API replaced by this (if any) |
|---|---|
void rail_app_task_init(void) | |
void rail_app_task(void *p_arg) | |
void handle_os_pending(void) | |
void post_os_flag(void) | |
sl_rail_time_t calculate_transaction_time(sl_rail_handle_t rail_handle) | |
EmberStatus emberSetRadioRxFifo(uint16_t rxFifoSize) |
Modified APIs#
None.
Removed APIs#
None.
Deprecated APIs#
None.
Bug Fixes#
| ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
| 1456611 | If RTOS is enabled, emberAfStackStatusCallback() is not called. | None |
|
| 1402669 | RAIL LIB assert codes are not coming out from the Connect Stack. | None |
|
Chip Enablement#
| Chip Family | OPNs / Boards / OPN Combinations | Supported Software Variants (if applicable) | Supported Modes | Supported Host Interfaces |
|---|---|---|---|---|
| EFR32xG29 |
|
All sample apps |
SoC |
UART,EUSART,SPI |
Application Example Changes#
New Examples | Modified Examples | Removed Examples | Deprecated Examples
New Examples#
None.
Modified Examples#
| Example Name | Changes | Supported Software Variants if applicable | Supported Modes | Supported OPNs / Boards / OPN Combinations | Supported Host Interfaces |
|---|---|---|---|---|---|
| Connect - NCP sample application |
|
Standard | NCP |
|
SPI, EUART, UART |
Removed Examples#
None.
Deprecated Examples#
None.
Known Issues and Limitations#
| ID | Issue or Limitation Description | GitHub / Salesforce Reference (if any) | Workaround (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|---|
| 652925 | EFR32XG21 is not supported for “Flex (Connect) - SoC Light Example DMP” and “Flex (Connect) - SoC Switch Example” | None. | None. |
|
| 1139850 | DMP instabilities with EFR32XG27 | None. | None. |
|
| 501561 | In the Legacy HAL component, the PA configuration is hardcoded regardless of the user or boards settings. | None. | Until this is changed to properly pull from the configuration header, the file ember-phy.c in the user's project will need to be modified by hand to reflect the desired PA mode, voltage, and ramp time. |
|
| None. | When running the RAIL Multiprotocol Library (used, for example, when running DMP Connect+BLE), IR Calibration is not performed because of a known issue in the RAIL Multiprotocol Library. As result, there is an RX sensitivity loss in the order of 3 or 4 dBm. | None. |
|
|
| None. | Updating the Baremetal sample applications to RTOS causes build errors. | None. |
Follow the Platforms guide sl_main Baremetal to RTOS Application Transition |
|
Impact of Release Changes#
Impact Statements | Migration Guide
Impact Statements#
None.
Migration Guide#
Click here for the migration guide for deprecated, removed, and modified items.
Using This Release#
What's in the Release? | Compatible Software | Installation and Use | Help and Feedback
What's in the Release?#
Connect SDK 4.1.0 showcasing the usage of the Connect stack 4.1.0 with the lates Simplicity SDK.
Compatible Software#
None.
Installation and Use#
To upgrade your existing software with this release, see instructions here.
To run your first demo, see our Getting Started Guides.
To kick start your development, see our Developer's Guide.
To learn more about the software in this release, dive into our online documentation.
For information about Secure Vault Integration, see here.
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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
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Help and Feedback#
Contact Silicon Labs Support.
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SDK Release and Maintenance Policy#
See our SDK Release and Maintenance Policy.