Arduino Uno R4 WiFi

Next-gen Uno with 32-bit Renesas RA4M1 Arm Cortex-M4 MCU, ESP32-S3 WiFi/Bluetooth and a built-in 12x8 LED matrix.

₹2,199 + 18% GST

SKU: BOTBIT-DEV-02 · Best for: WiFi-connected IoT projects that push sensor data to cloud dashboards or Arduino Cloud

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Overview

About Arduino Uno R4 WiFi.

The Arduino Uno R4 WiFi is the modern successor to the classic Uno, keeping the familiar shape, pinout and shield compatibility while replacing the old 8-bit chip with a powerful 32-bit Renesas RA4M1 Arm Cortex-M4 microcontroller running at 48 MHz. It adds an on-board ESP32-S3 module for WiFi and Bluetooth 5.0, a built-in 12x8 red LED matrix, a CAN bus, a DAC and a much larger memory pool.

It is an appealing choice in India for makers who have outgrown the R3 but want to reuse their existing shields, wiring knowledge and code. The extra speed and 32 KB of SRAM make it comfortable for connected IoT dashboards, data logging to the cloud, and projects that were simply too heavy for the ATmega328P. Despite the upgrade, it still runs on the same beginner-friendly Arduino IDE and keeps 5V-tolerant I/O for easy migration.

The built-in LED matrix lets you show animations, text and simple graphics with no extra hardware, and the on-board Qwiic connector makes it easy to chain I2C sensors. It is the natural upgrade path for anyone who loves the Uno form factor but needs wireless connectivity.

Key features

Why it stands out.

32-bit Renesas RA4M1 Arm Cortex-M4 MCU at 48 MHz, a major jump over the 8-bit R3

On-board ESP32-S3 co-processor providing 2.4 GHz WiFi and Bluetooth 5.0 (LE)

Built-in 12x8 red LED matrix for text, animations and simple graphics with no add-ons

USB-C connector for power and programming; wider USB-C or VIN input up to 24V

256 KB Flash and 32 KB SRAM, far larger than the R3, plus a 12-bit DAC and CAN bus

Qwiic I2C connector and full backward compatibility with classic Uno shields and code

Specifications

Selection facts.

Main Microcontroller	Renesas RA4M1 (Arm Cortex-M4) at 48 MHz
Connectivity Co-processor	Espressif ESP32-S3 (WiFi + Bluetooth 5.0 LE)
Flash Memory	256 KB
SRAM	32 KB
EEPROM	8 KB
Digital I/O Pins	14 (6 provide PWM)
Analog Input Pins	6 (ADC up to 14-bit)
Operating / Logic Voltage	5V
Recommended Input Voltage (VIN)	6-24V
Special Features	12x8 LED matrix, 12-bit DAC, CAN bus, USB-C, Qwiic

Applications

Where it is used.

WiFi-connected IoT projects that push sensor data to cloud dashboards or Arduino Cloud
Bluetooth Low Energy projects communicating with phones and other BLE devices
Scrolling text, clocks and animations shown directly on the built-in 12x8 LED matrix
Data logging and monitoring that needs more speed and memory than the 8-bit Uno
Reusing existing Arduino shields on a faster, connected 32-bit platform
CAN-bus experiments and automotive/industrial signalling prototypes

Buying guide

How to choose.

Buy the Uno R4 WiFi if you want the classic Uno form factor and shield compatibility but need built-in WiFi/Bluetooth, more memory and a much faster processor. It is ideal for connected IoT, home dashboards and any project the ATmega328P struggled to run.

If you only need offline blinking-LED and simple-sensor learning, the cheaper R3 is enough. If you do not need connectivity but want speed, there is also a non-WiFi Uno R4 Minima. Choose the R4 WiFi specifically when wireless is part of the plan or you want the LED matrix.

Pair it with I2C Qwiic sensors for solder-free wiring, a USB-C cable for power and programming, and any existing Uno shields you already own. For cloud projects, the free Arduino Cloud service works out of the box with this board.

FAQ

Common questions.

Is the Uno R4 WiFi compatible with my old Uno R3 shields and code?

Yes. It keeps the same board outline, pin positions and 5V logic, so classic Uno shields fit and most R3 sketches recompile and run. A few libraries written for AVR-specific registers may need updated versions, but the vast majority of Arduino code works unchanged.

How do I use the WiFi and Bluetooth features?

WiFi and Bluetooth are handled by the on-board ESP32-S3 and exposed through the WiFiS3 library that ships with Arduino IDE board support. Install the 'Arduino UNO R4 Boards' package via Boards Manager, and you get ready-made examples for WiFi web servers, MQTT and BLE.

What cable and voltage does it need?

It uses USB-C for power and programming. For external supply it accepts 6-24V on VIN, a much wider range than the R3's 7-12V, which is convenient for battery and industrial power sources.

Do I need extra hardware to use the LED matrix?

No. The 12x8 red LED matrix is built onto the board and driven directly by the RA4M1. Arduino provides an LED Matrix library with examples for scrolling text, frames and simple animations, so you can light it up with a few lines of code.

Is it a good first Arduino for a complete beginner?

It works fine for beginners and uses the same friendly IDE, but if your goal is only to learn basics and follow the most common tutorials, the R3 is cheaper and has slightly more legacy documentation. Choose the R4 WiFi if connectivity or the LED matrix is important to you.