Seeed Studio XIAO RA4M1 Board Now Supported in Zephyr RTOS
Support for the Seeed Studio XIAO RA4M1 board has just been merged into Zephyr RTOS by ZMK lead developer Pete Johanson.
The Zephyr Project just added support for Seeed Studio's XIAO RA4M1 — currently the smallest development board based on the 32-bit Renesas RA4M1. The pull request was submitted by Pete Johanson, the creator and lead developer of the popular open-source keyboard firmware ZMK Firmware.
Additionally, this PR adds Zephyr support for the Renesas Flash Programmer (RFP) Host Tools (rfp-cli). This new west runner allows flashing the firmware to the board without the need for an external programmer.
Support for the XIAO RA4M1 has been highly anticipated. "We got so many XIAO owners in the community asking for this." says Meilily Li, Product Marketing Manager at Seeed Studio.
The XIAO RA4M1 is the latest in the XIAO series of boards to be supported by Zephyr, and the first XIAO board to include an MCU from Renesas. The XIAO series boards are known for their compact, thumb-sized form factor. Measuring 21 mm x 17.8 mm, their small footprint makes them suitable for wearable devices and other small projects. The XIAO series boards are also popular in the community for developing mechanical keyboards.
Gareth Halfacree first covered the XIAO RA4M1 when it was announced eight months ago. The board is powered by Renesas' 32-bit Arm Cortex-M4 R7FA4M1AB3CFM MCU operating at up to 48 MHz with FPU, 256 KB of flash memory, and 32 KB of SRAM. This same MCU was popularized in 2023 when Arduino announced that it would power their Arduino UNO R4 series of boards.
The board features charge, user, and RGB LEDs, as well as a reset and boot buttons.
The user LED can be tested out of the box without writing any code by building Zephyr's blinky sample app for the board:
west build -b xiao_ra4m1 samples/basic/blinky
west flashThe XIAO RA4M1 also comes equipped with a 14-bit ADC, 12-bit DAC, CAN BUS, USB 2.0, and an onboard RGB LED. Eight new IO pins on the back (compared to previous XIAO boards) provide 19 GPIOs in total, enabling more complex applications.
The Zephyr documentation page for the XIAO RA4M1 provides a detailed overview of the features currently supported by Zephyr, along with how to get started programming and debugging the board.
