UNO R4-Compatible WiFi Board — RA4M1 & ESP32-S3, Wi-Fi, Bluetooth, USB-C, CAN Bus, 12-Bit DAC, LED Matrix

📋 Overview

The UNO R4-Compatible WiFi Board is a UNO-format development board built around the same core chipset found in certain officially branded UNO R4 WiFi boards: a 32-bit Renesas RA4M1 microcontroller paired with an ESP32-S3 module for Wi-Fi and Bluetooth. This is a compatible board, not a genuine Arduino-branded product — but because it uses the identical RA4M1 and ESP32-S3 chipset, it runs the same sketches, libraries, and board packages used across the maker community.

Under the hood, this board uses a dual-MCU design: the RA4M1 runs your sketch and controls all onboard peripherals, while a separate dual-core ESP32-S3 coprocessor handles Wi-Fi and Bluetooth 5 wireless connectivity. On top of that, you get a built-in 12x8 LED matrix, a 12-bit DAC, an onboard op-amp, USB-C, a Qwiic I2C connector, and CAN bus support — all while keeping the classic 5V UNO operating voltage and pin layout for shield compatibility.

⭐ Key Features

• Renesas RA4M1 Microcontroller — 32-bit Arm Cortex-M4 at 48 MHz with FPU, 256 kB flash, 32 kB SRAM, 8 kB EEPROM
• ESP32-S3 Wi-Fi & Bluetooth Coprocessor — Dual-core module with Wi-Fi 4 (802.11 b/g/n, 2.4 GHz) and Bluetooth 5 LE built in, no shield required
• Built-In 12x8 LED Matrix — 96 programmable red LEDs for animations, scrolling text, and live sensor readouts
• 12-Bit DAC & Onboard Op-Amp — Generate analog waveforms and buffer or amplify analog signals directly on the board
• USB-C, Qwiic I2C & CAN Bus — Modern USB-C programming port, plug-and-play Qwiic connector, and a CAN controller for automotive and industrial projects (external transceiver required)
• Full UNO Shield Compatibility — Same 5V operating voltage and pin layout as classic UNO boards, so most existing shields and accessories still work

📌 Module Pinout

Looking at the board from the top, with the USB-C port and DC jack at the top-left and the digital header along the top edge:

⚠️ Important: The ESP32-S3 coprocessor, its dedicated header, and the Qwiic connector operate at 3.3V and are not 5V tolerant. Never connect a 5V signal to these — doing so can permanently damage the ESP32-S3 module.

📊 Specifications

🔌 CAN Bus Wiring

The RA4M1's CAN controller is built into the microcontroller but has no onboard transceiver. You'll need an external CAN transceiver module (such as an SN65HVD230) to connect to an actual CAN bus network.

📝 Note: A CAN transceiver is required for this board to communicate on a real CAN bus network — the pins alone will not work without one.

📦 What's in the Box

• 1x UNO R4-Compatible WiFi Board

USB-C cable, jumper wires, and shields are not included.

🔌 Compatible With

• Arduino IDE (Desktop) and Arduino Cloud Editor, using an RA4M1-compatible board package
• Existing 5V UNO-format shields and accessories
• Qwiic-standard I2C sensor and actuator modules (3.3V only)
• External CAN transceiver modules (e.g., SN65HVD230)

🎯 Typical Applications

• IoT and smart home projects using built-in Wi-Fi and Bluetooth
• Visual feedback and status displays using the onboard LED matrix
• Audio signal generation and simple analog projects using the 12-bit DAC
• Automotive, robotics, or industrial prototyping using CAN bus
• STEM education and general-purpose learning projects
• Upgrading existing 8-bit UNO shield-based projects to more memory and speed

⚠️ Important Notes

• Do not power the board with more than 5V through the USB-C port
• Never connect a 5V signal to the ESP32-S3 header or the Qwiic connector — both are 3.3V only and not 5V tolerant
• Digital GPIO pins are rated for a maximum of 8 mA — use an external driver or power supply for higher-current loads like motors or servos
• A4/A5 are shared with the main I2C bus — avoid using them as analog inputs while I2C devices are active on that bus
• CAN bus functionality requires an external transceiver module; it will not work with the pins alone
• Operating temperature range is -40°C to +85°C; USB input should stay within 4.8–5.5V

📄 Documentation & Resources

Sold and supported by Envistia Mall. Shipped from the United States. This product is a compatible board using the same RA4M1 and ESP32-S3 chipset as certain officially branded microcontroller boards, but it is not manufactured, endorsed, or affiliated with the original brand owner, and is not sold under that brand's trademark. Please refer to the linked User Guide for full setup instructions, pinout details, and safety information. Envistia Mall is not liable for damage resulting from improper wiring, incorrect voltage, or misuse of this product. Always follow proper electrical safety practices when working with development boards and connected components.