This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Arduino UNO R4

Overview

The Arduino UNO R4 Minima/WiFi is a development board featuring the Renesas RA4M1 SoC in the Arduino form factor and is compatible with traditional Arduino.

Hardware

  • Renesas RA4MA1 Processor (ARM Cortex-M4 at 48 MHz)

  • 256 KiB flash memory and 32 KiB of RAM

  • One user LEDs

  • One reset button

  • One WiFi Transceiver (Arduino UNO R4 WiFi only)

  • One 12x8 LED Matrix (Arduino UNO R4 WiFi only)

  • Built-in CMSIS-DAP debug adapter (Arduino UNO R4 WiFi only)

Supported Features

The Arduino UNO R4 Minima/Wifi board configuration supports the following hardware features:

Interface

Controller

Driver/Component

GPIO

on-chip

I/O ports

UART

on-chip

Serial ports

Programming and debugging

Debug adapter

A debug adapter is required to flash and debug programs. Arduino UNO R4 WiFi has a built-in debug adapter that you can use for flashing and debugging.

In the Arduino UNO R4 Minima case, You need to prepare debug adapter separately. A 5V-compatible CMSIS-DAP adapter adapts to this board.

Building & Flashing

You can build and flash with west flash command (See Building an Application and Run an Application for more details).

Here is an example for building and flashing the Blinky application.

# From the root of the zephyr repository
west build -b arduino_uno_r4_minima samples/basic/blinky
west flash

# From the root of the zephyr repository
west build -b arduino_uno_r4_wifi samples/basic/blinky
west flash

Debugging

Debugging can be done with west debug command. The following command is debugging the Blinky application. Also, see the instructions specific to the debug server that you use.

# From the root of the zephyr repository
west build -b arduino_uno_r4_minima samples/basic/blinky
west debug

# From the root of the zephyr repository
west build -b arduino_uno_r4_wifi samples/basic/blinky
west debug

Using pyOCD

Various debug adapters, including cmsis-dap probes, can debug the Arduino UNO R4 with pyOCD. The default configuration uses the pyOCD for debugging. You must install CMSIS-Pack when flashing or debugging Arduino UNO R4 Minima with pyOCD. If not installed yet, execute the following command to install CMSIS-Pack for Arduino UNO R4.

pyocd pack install r7fa4m1ab

Restoring Arduino Bootloader

If you corrupt the Arduino bootloader, you can restore it with the following command.

wget https://raw.githubusercontent.com/arduino/ArduinoCore-renesas/main/bootloaders/UNO_R4/dfu_minima.hex
pyocd flash -e sector -a 0x0 -t r7fa4m1ab dfu_minima.hex

wget https://raw.githubusercontent.com/arduino/ArduinoCore-renesas/main/bootloaders/UNO_R4/dfu_wifi.hex
pyocd flash -e sector -a 0x0 -t r7fa4m1ab dfu_wifi.hex