RIOT-OS 2026.04 "Fire Rizzlease" is out
RIOT-OS 2026.04, codenamed Fire Rizzlease š«Ŗš, was released on May 6, 2026. RIOT is a multi-threading operating system targeting microcontrollers found in the Internet of Things ā from 8-bit and 16-bit MCUs to lightweight 32-bit processors ā with a focus on energy-efficiency, soft real-time capabilities, and a small memory footprint.
This release spans 84 days of development, 125 merged pull requests composed of 229 commits, and contributions from 27 people. A notable stat: 1,141,523 lines were deleted against only 25,007 inserted, largely thanks to a major vendor code cleanup.
Codeberg mirror
RIOT is now synced to Codeberg (#21997). This gives the project a home on a non-profit, community-driven forge alongside its GitHub presence, a welcome step for an independent open-source project.
Massive EFM32 vendor code removal
Over one million lines of vendor code have been removed from the EFM32 family, replaced by a pkg/gecko_sdk dependency (#22040). This is the single biggest contributor to the impressive deletion count and results in a much leaner and more maintainable codebase for Silicon Labs EFM32-based boards.
Raspberry Pi Pico 2 / RP2350 improvements
The RP2350 support received a thorough overhaul (#21753):
- Unified abstractions between the RISC-V and ARM cores of the RP2350.
- Added the XH3IRQ interrupt controller.
- Updated UART driver.
- Added RISC-V support.
The scope of this work was large enough to inspire a bachelor's thesis at HAW Hamburg.
New board and CPU support
Three new targets join the supported hardware list:
- pro-micro-nrf52840 (#22089) ā a popular nRF52840-based Pro Micro form-factor board.
- slstk3301a (#22069) ā Silicon Labs EFM32 Tiny Gecko starter kit.
- STM32H7 (#21978) ā high-performance STM32 family, with additional peripheral support for the nucleo-h753zi (#22076).
New device drivers
- AMG88xx (#22104) ā infrared array sensor (thermal camera) from Panasonic.
- ADS1X1X (#21694) ā family of Texas Instruments IĀ²C ADCs.
Guide site and documentation
The RIOT Guide Site continues to grow as the default entry point for new users, progressively replacing Doxygen for prose documentation. This release adds:
- More tutorials.
- An experimental Supported Boards section.
- Unit tests in tutorials (#22042).
- Updated Astro v6 framework (#22145).
The Doxygen API reference remains available at api.riot-os.org.
Networking improvements
Several additions to the GNRC networking stack:
- New gnrc_pktshark module to pretty-print network traffic (#21284).
- gnrc_ipv6_nib_dyn_lladdr_get() API (#22013).
- ABR (Authoritative Border Router) now run-time configurable (#21081).
- Generic UDP shell command (#22049).
Notable bug fixes
43 bugs were fixed in this release, including:
- ESP8266 crashes on reboot and startup (#22014, #22010).
- Potential buffer overflow in the atwinc15x0 driver (#22041).
- NanoCoAP message corruption in coap_build_reply() (#22094).
- Wrong byte order for gyro and accelerometer reads in the MPU-9x50 driver (#22135).
- LVGL configuration and SDL issues on native (#22005, #22139).