Changelog for nRF Connect SDK v3.1.0-preview2

This changelog reflects the most relevant changes from the latest official release.

Known issues 

Known issues are only tracked for the latest official release. See known issues for nRF Connect SDK v3.0.0 for the list of issues valid for the latest release.

Changelog 

The following sections provide detailed lists of changes by component.

IDE, OS, and tool support 

No changes since the latest nRF Connect SDK release.

Board support 

Added:
- Bias-pull-up for Thingy:91 X nRF9151 UART RX pins.
- Alternative partition tables for Thingy:91 X.

Build and configuration system 

No changes since the latest nRF Connect SDK release.

Bootloaders and DFU 

No changes since the latest nRF Connect SDK release.

Developing with nRF91 Series 

No changes since the latest nRF Connect SDK release.

Developing with nRF70 Series 

No changes since the latest nRF Connect SDK release.

Developing with nRF54L Series 

Increased the default value of the CONFIG_MPSL_HFCLK_LATENCY Kconfig option to support slower crystals. See the Kconfig description for a detailed description on how to select the correct value for a given application.

Developing with nRF54H Series 

No changes since the latest nRF Connect SDK release.

Developing with nRF53 Series 

No changes since the latest nRF Connect SDK release.

Developing with nRF52 Series 

No changes since the latest nRF Connect SDK release.

Developing with Thingy:91 X 

No changes since the latest nRF Connect SDK release.

Developing with Thingy:91 

No changes since the latest nRF Connect SDK release.

Developing with Thingy:53 

No changes since the latest nRF Connect SDK release.

Developing with PMICs 

No changes since the latest nRF Connect SDK release.

Developing with Front-End Modules 

No changes since the latest nRF Connect SDK release.

Developing with custom boards 

No changes since the latest nRF Connect SDK release.

Security 

Added the new section about Cryptography in the nRF Connect SDK. The new section includes pages about Cryptographic architecture overview (new page) and Cryptographic drivers (moved from nRF Security library).

Protocols 

No changes since the latest nRF Connect SDK release.

Amazon Sidewalk

No changes since the latest nRF Connect SDK release.

Bluetooth® LE

No changes since the latest nRF Connect SDK release.

Bluetooth Mesh

No changes since the latest nRF Connect SDK release.

DECT NR+

No changes since the latest nRF Connect SDK release.

Enhanced ShockBurst (ESB)

No changes since the latest nRF Connect SDK release.

Gazell

No changes since the latest nRF Connect SDK release.

Matter

Added FastTrack Recertification and Portfolio Certification programs.
Updated:
- The west zap-generate command to remove previously generated ZAP files before generating new files. To skip removing the files, use the --keep-previous argument.
- The Creating manufacturer-specific clusters in Matter application user guide by adding information about implementing custom commands.

Matter fork

No changes since the latest nRF Connect SDK release.

nRF IEEE 802.15.4 radio driver

No changes since the latest nRF Connect SDK release.

Thread

No changes since the latest nRF Connect SDK release.

Wi-Fi®

No changes since the latest nRF Connect SDK release.

Applications 

No changes since the latest nRF Connect SDK release.

Connectivity bridge

Fixed to resume Bluetooth connectable advertising after a disconnect.

IPC radio firmware

No changes since the latest nRF Connect SDK release.

Matter bridge

No changes since the latest nRF Connect SDK release.

nRF5340 Audio

Added:
- Experimental support for Audio on the nRF5340 DK, with LED state indications and button controls.
Updated:
- The application to use the NFC.TAGHEADER0 value from FICR as the broadcast ID instead of using a random ID.
- The application to change from Newlib to Picolib to align with nRF Connect SDK and Zephyr.
- The application to use the Network Buffers API to pass audio data between threads. The Network Buffers will also contain the metadata about the audio stream in the user_data section of the API. This change was done to transition to standard Zephyr APIs, as well as to have a structured way to pass N-channel audio between modules.
- The optional buildprog tool to use nRF Util instead of nrfjprog that has been deprecated.

nRF Desktop

Updated:
- The application configurations for dongles on memory-limited SoCs (such as nRF52820) to reuse the system workqueue for GATT Discovery Manager (CONFIG_BT_GATT_DM_WORKQ_SYS). This helps to reduce RAM usage.
- Link Time Optimization (CONFIG_LTO) to be enabled in MCUboot configurations of the nRF52840 DK (mcuboot_smp, mcuboot_qspi). LTO no longer causes boot failures and it reduces the memory footprint.
- The HID Service module to use shared callbacks for multiple HID reports:
  - Use the bt_hids_inp_rep_send_userdata() function to send HID input reports while in report mode.
  - Use an extended callback with the notification event to handle subscriptions for HID input reports in report mode (bt_hids_inp_rep).
  - Use generic callbacks to handle HID feature and output reports.
  This approach simplifies the process of adding support for new HID reports.

nRF Machine Learning (Edge Impulse)

No changes since the latest nRF Connect SDK release.

Serial LTE modem

Updated:
- The AT#XPPP command to support the CID parameter to specify the PDN connection used for PPP.
- The #XPPP notification to include the CID of the PDN connection used for PPP.
- The initialization of the application to ignore a failure in nRF Cloud module initialization. This occurs sometimes especially during development.
- The initialization of the application to send “INIT ERROR” over to UART and show clear error log to indicate that the application is not operational in case of failing initialization.
- The PPP downlink data to trigger the indicate pin when SLM is in idle.
- The AT#XTCPCLI and the AT#XUDPCLI commands to support CID of the PDN connection.

Thingy:53: Matter weather station

No changes since the latest nRF Connect SDK release.

Samples 

This section provides detailed lists of changes by sample.

Amazon Sidewalk samples

No changes since the latest nRF Connect SDK release.

Bluetooth samples

Bluetooth: ISO time synchronization sample:
- Fixed an issue where the sample would assert with the CONFIG_ASSERT Kconfig option enabled. This was due to calling the bt_iso_chan_send() function from a timer ISR handler and sending SDUs to the controller with invalid timestamps.

No changes since the latest nRF Connect SDK release.

Bluetooth Mesh samples

No changes since the latest nRF Connect SDK release.

Bluetooth Fast Pair samples

Bluetooth Fast Pair: Locator tag sample:
- Added possibility to build and run the sample without the motion detector support (with the CONFIG_BT_FAST_PAIR_FMDN_DULT_MOTION_DETECTOR Kconfig option disabled).
- Updated the Android notifications about firmware updates section to improve the test procedure. The application provides now an additional log message to indicate that the firmware version is being read.

Cellular samples

Deprecated the LTE Sensor Gateway sample. It is no longer maintained.
nRF Cloud multi-service sample:
- Added support for native simulator platform and updated the documentation accordingly.
Cellular: nRF Device provisioning sample:
- Updated the sample to use Zephyr’s Connection Manager feature.

Cryptography samples

No changes since the latest nRF Connect SDK release.

Debug samples

No changes since the latest nRF Connect SDK release.

DECT NR+ samples

No changes since the latest nRF Connect SDK release.

Edge Impulse samples

No changes since the latest nRF Connect SDK release.

Enhanced ShockBurst samples

No changes since the latest nRF Connect SDK release.

Gazell samples

No changes since the latest nRF Connect SDK release.

Keys samples

No changes since the latest nRF Connect SDK release.

Matter samples

Changed Bluetooth Low Energy variant of the Soft Device Controller (SDC) to use the Peripheral-only role in all Matter samples.

Networking samples

Download sample:
- Added the CONFIG_SAMPLE_PROVISION_CERT Kconfig option to provision the root CA certificate to the modem. The certificate is provisioned only if the CONFIG_SAMPLE_SECURE_SOCKET Kconfig option is set to y.

NFC samples

Added experimental llvm toolchain support for the nrf54l15dk/nrf54l15/cpuapp board target to the following samples:
- NFC: Writable NDEF message
- NFC: Shell
NFC: Text record sample:
- Added support for the nrf54l15dk/nrf54l15/cpuapp/ns board target.

nRF5340 samples

No changes since the latest nRF Connect SDK release.

Peripheral samples

Radio test (short-range) sample:
- Added experimental llvm toolchain support for the nrf54l15dk/nrf54l15/cpuapp board target.

PMIC samples

No changes since the latest nRF Connect SDK release.

Protocol serialization samples

No changes since the latest nRF Connect SDK release.

SDFW samples

No changes since the latest nRF Connect SDK release.

Sensor samples

No changes since the latest nRF Connect SDK release.

SUIT samples

No changes since the latest nRF Connect SDK release.

Trusted Firmware-M (TF-M) samples

TF-M secure peripheral partition sample:
- Added support for the nrf54l15dk/nrf54l15/cpuapp/ns board target.

Thread samples

No changes since the latest nRF Connect SDK release.

Wi-Fi samples

Wi-Fi: Radio test samples:
- Updated Wi-Fi: Radio test (Multi domain) and Wi-Fi: Bluetooth LE Wi-Fi Radio test (Single domain) samples to clarify platform support for single-domain and multi-domain radio tests.

Other samples

No changes since the latest nRF Connect SDK release.

Drivers 

This section provides detailed lists of changes by driver.

Added the sQSPI MSPI shim driver that allows for communication with devices that use MSPI bus-based Zephyr drivers.

Wi-Fi drivers

No changes since the latest nRF Connect SDK release.

Flash drivers

No changes since the latest nRF Connect SDK release.

Libraries 

This section provides detailed lists of changes by library.

Binary libraries

No changes since the latest nRF Connect SDK release.

Bluetooth libraries and services

Google Fast Pair Service (GFPS) library:
- Updated the CONFIG_BT_FAST_PAIR_FMDN_RING_REQ_TIMEOUT_DULT_MOTION_DETECTOR Kconfig option dependency. The dependency has been updated from the CONFIG_BT_FAST_PAIR_FMDN_DULT Kconfig option to CONFIG_BT_FAST_PAIR_FMDN_DULT_MOTION_DETECTOR.

Common Application Framework

No changes since the latest nRF Connect SDK release.

Debug libraries

Added an experimental Zephyr Core Dump backend that writes a core dump to an internal flash or RRAM partition. To enable this backend, set the CONFIG_DEBUG_COREDUMP_BACKEND_OTHER and CONFIG_DEBUG_COREDUMP_BACKEND_NRF_FLASH_PARTITION Kconfig options.
CPU load measurement library:
- Added prefix NRF_ to all Kconfig options (for example, CONFIG_NRF_CPU_LOAD) to avoid conflicts with Zephyr Kconfig options with the same names.

DFU libraries

No changes since the latest nRF Connect SDK release.

Gazell libraries

No changes since the latest nRF Connect SDK release.

Security libraries

nRF Security library:
- Updated:
  - The name of the Kconfig option CONFIG_PSA_USE_CRACEN_ASYMMETRIC_DRIVER to CONFIG_PSA_USE_CRACEN_ASYMMETRIC_ENCRYPTION_DRIVER, which is more descriptive and more consistent with the options of the other drivers.
  - The placement of the page about nRF Security drivers. The page was moved to Cryptography in the nRF Connect SDK and renamed to Cryptographic drivers.

Modem libraries

AT parser library:
- Added support for parsing DECT NR+ modem firmware names.
- Updated the following macros and functions to return -ENODATA when the target subparameter to parse is empty:
  - at_parser_num_get macro
  - Functions:
LTE link control library:
- Added the CONFIG_LTE_LC_DNS_FALLBACK_MODULE and CONFIG_LTE_LC_DNS_FALLBACK_ADDRESS Kconfig options to enable setting a fallback DNS address. The CONFIG_LTE_LC_DNS_FALLBACK_MODULE Kconfig option is enabled by default. If the application has configured a DNS server address in Zephyr’s native networking stack, using the CONFIG_DNS_SERVER1 Kconfig option, the same server is set as the fallback address for DNS queries offloaded to the nRF91 Series modem. Otherwise, the CONFIG_LTE_LC_DNS_FALLBACK_ADDRESS Kconfig option controls the fallback DNS server address that is set to Cloudflare’s DNS server: 1.1.1.1 by default. The device might or might not receive a DNS address by the network during PDN connection. Even within the same network, the PDN connection establishment method (PCO vs ePCO) might change when the device operates in NB-IoT or LTE Cat-M1, resulting in missing DNS addresses when one method is used, but not the other. Having a fallback DNS address ensures that the device always has a DNS to fallback to.
Modem SLM library:
- Added:
  - The CONFIG_MODEM_SLM_UART_RX_BUF_COUNT Kconfig option for configuring RX buffer count.
  - The CONFIG_MODEM_SLM_UART_RX_BUF_SIZE Kconfig option for configuring RX buffer size.
  - The CONFIG_MODEM_SLM_UART_TX_BUF_SIZE Kconfig option for configuring TX buffer size.
  - The CONFIG_MODEM_SLM_AT_CMD_RESP_MAX_SIZE Kconfig option for buffering AT command responses.
- Updated the UART implementation between the host device, using the Modem SLM library, and the device running the Serial LTE modem application.
- Removed:
  - The CONFIG_MODEM_SLM_DMA_MAXLEN Kconfig option. Use CONFIG_MODEM_SLM_UART_RX_BUF_SIZE instead.
  - The modem_slm_reset_uart() function, as there is no longer a need to reset the UART.

Multiprotocol Service Layer libraries

No changes since the latest nRF Connect SDK release.

Libraries for networking

nRF Cloud library:
- Updated:
  - To return negative errno.h errors instead of positive ZCBOR errors.
  - The CoAP download authentication to no longer depend on the CoAP Client library.
nRF Cloud device provisioning library:
- Fixed an issue where the results from the zsock_getaddrinfo() function were not freed when the CoAP protocol was used for connection establishment.

Libraries for NFC

No changes since the latest nRF Connect SDK release.

nRF RPC libraries

No changes since the latest nRF Connect SDK release.

Other libraries

Detecting Unwanted Location Trackers (DULT) library:
- Updated the write handler of the accessory non-owner service (ANOS) GATT characteristic to no longer assert on write operations if the DULT was not enabled at least once.

Shell libraries

No changes since the latest nRF Connect SDK release.

sdk-nrfxlib

See the changelog for each library in the nrfxlib documentation for additional information.

Scripts 

Added the ncs_ironside_se_update.py script in the scripts/west_commands folder. The script adds the west command west ncs-ironside-se-update for installing an IronSide SE update.
HID configurator for nRF Desktop Python script:
- Updated:
  - The udev rules for Debian, Ubuntu, and Linux Mint HID host computers (replaced the 99-hid.rules file with 60-hid.rules). This is done to ensure that the rules are properly applied for an nRF Desktop device connected directly over Bluetooth LE. The new udev rules are applied to any HID device that uses the Nordic Semiconductor Vendor ID (regardless of Product ID).
  - The HID device discovery to ensure that a discovery failure of a HID device would not affect other HID devices. Without this change, problems with discovery of a HID device could lead to skipping discovery and listing of other HID devices (even if the devices work properly).

Integrations 

This section provides detailed lists of changes by integration.

Google Fast Pair integration

No changes since the latest nRF Connect SDK release.

Edge Impulse integration

No changes since the latest nRF Connect SDK release.

Memfault integration

No changes since the latest nRF Connect SDK release.

AVSystem integration

No changes since the latest nRF Connect SDK release.

nRF Cloud integration

No changes since the latest nRF Connect SDK release.

CoreMark integration

No changes since the latest nRF Connect SDK release.

DULT integration

No changes since the latest nRF Connect SDK release.

The MCUboot fork in nRF Connect SDK (sdk-mcuboot) contains all commits from the upstream MCUboot repository up to and including 81315483fcbdf1f1524c2b34a1fd4de6c77cd0f4, with some nRF Connect SDK specific additions.

The code for integrating MCUboot into nRF Connect SDK is located in the ncs/nrf/modules/mcuboot folder.

The following list summarizes both the main changes inherited from upstream MCUboot and the main changes applied to the nRF Connect SDK specific additions:

Fixed an issue related to referencing the ARM Vector table of the application, which causes jumping to wrong address instead of the application reset vector for some builds when Zephyr LTO (Link Time Optimization) was enabled.

Zephyr 

The Zephyr fork in nRF Connect SDK (sdk-zephyr) contains all commits from the upstream Zephyr repository up to and including 9a6f116a6aa9b70b517a420247cd8d33bbbbaaa3, with some nRF Connect SDK specific additions.

For the list of upstream Zephyr commits (not including cherry-picked commits) incorporated into nRF Connect SDK since the most recent release, run the following command from the ncs/zephyr repository (after running west update):

git log --oneline 9a6f116a6a ^fdeb735017

For the list of nRF Connect SDK specific commits, including commits cherry-picked from upstream, run:

git log --oneline manifest-rev ^9a6f116a6a

The current nRF Connect SDK main branch is based on revision 9a6f116a6a of Zephyr.

Note

For possible breaking changes and changes between the latest Zephyr release and the current Zephyr version, refer to the Zephyr release notes.

Additions specific to nRF Connect SDK

No changes since the latest nRF Connect SDK release.