XIAO RA4M1

Overview

The XIAO RA4M1 integrates Renesas’ RA4M1 chip (32-bit ARM® Cortex®-M4 MCU up to 48 MHz) into the classic XIAO form factor. This development board offers 256KB Flash, 32KB SRAM, 8KB EEPROM, a USB 2.0 connector, reset and boot buttons, 3 LEDs, a 14-bit A/D converter, a 12-bit D/A converter, and a CAN BUS interface. With onboard charging circuitry and low-power modes (as low as 45μA), it’s ideal for battery-powered applications. Sharing the same 32-bit RA4M1 microcontroller as the Arduino Uno R4, it’s natively compatible with Arduino IDE and the extensive XIAO accessories, making it the perfect starting point for electronics projects.

Renesas RA4M1 Microcontroller Group

  • R7FA4M1AB3CNE

  • 48-pin LQFP package

  • 48 MHz Arm® Cortex®-M4 core with Floating Point Unit (FPU)

  • 32 KB SRAM

  • 256 KB code flash memory

  • 8 KB data flash memory

Connectivity

  • A Device USB connector for the Main MCU

  • Pin headers for access to power and signals

  • Bottom pads for access to signals, SWD, and battery hookup

Operating voltage

  • External 5 V input through the Debug USB connector supplies the on-board power regulator to power logic and interfaces on the board. External 5 V or 3.3 V may be also supplied through alternate locations on the board.

  • An external 3.7 V LiPo battery can be connected and the board includes the ability to charge the battery when 5 V power is supplied.

  • A yellow User LED, controlled by the Main MCU firmware

  • MCU reset push-button switch

  • MCU boot push-button switch

Hardware

Detailed hardware features can be found at:

Supported Features

The xiao_ra4m1 board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

Programming and Debugging

The xiao_ra4m1 board supports the runners and associated west commands listed below.

flash debug

Applications for the xiao_ra4m1 board can be built, flashed, and debugged in the usual way. See Building an Application and Run an Application for more details on building and running.

Flashing

Program can be flashed to XIAO RA4M1 via the built in RA4 USB bootloader.

To flash the program to board

  1. Connect the XIAO RA4M1 USB port to the host.

  2. Enter bootloader mode by holding the right Boot button, and tapping the left Reset button. The Boot button needs to be held for a second or two after the Reset has been released.

  3. Execute west command

# From the root of the zephyr repository
west build -b xiao_ra4m1 samples/hello_world
west flash

Debugging

To debug on the XIAO RA4M1, connect an external debugger to the SWD pads on the bottom of the controller. Once completed, debugging can be performed using Zephyr’s standard method (see Run an Application). The following sample demonstrates how to debug using JLink:

# From the root of the zephyr repository
west build -b xiao_ra4m1 samples/basic/blinky
west debug

References