Board

Arduino Uno R4 WiFi specs, pinout & datasheets

Microcontroller board · Arduino · Released June 2023

The Uno R4 with an ESP32-S3 for Wi-Fi and Bluetooth LE, a 12 × 8 LED matrix and a Qwiic connector.

Photo: Arduino, CC BY-SA 3.0, via Wikimedia Commons

Chip / SoC: Renesas RA4M1 (R7FA4M1AB3CFM)
CPU: Arm Cortex-M4F
Clock: 48 MHz
RAM: 32 KB SRAM
Flash: 256 KB
Wireless: Wi-Fi and Bluetooth LE via an on-board ESP32-S3
I/O voltage: 5 V
Released: June 2023
Status: In production

Draft entry: these specs were compiled from the linked sources and are waiting for a second check. Spotted a mistake? Use the form at the end of the page.

Specifications

14 specs

Chip / SoC: Renesas RA4M1 (R7FA4M1AB3CFM)^[1]
CPU: Arm Cortex-M4F^[1]
Clock: 48 MHz^[1]
RAM: 32 KB SRAM^[1]
Flash: 256 KB^[1]
EEPROM: 8 KB data flash^[1]
GPIO: 14 digital I/O^[1]
Analog: 6 analog inputs (up to 14-bit); 12-bit DAC on A0^[1]
I/O voltage: 5 V^[1]
Input voltage: 6–24 V on VIN or the barrel jack; 5 V via USB-C^[1]
Wireless: Wi-Fi and Bluetooth LE via an on-board ESP32-S3^[1]
USB: USB-C, native USB on the RA4M1 (HID capable)^[1]
Launch price: US$27.50^[3]
Upload limits: 256 KB flash, 32 KB RAM^[4]

Upload limits are what a sketch or firmware may use after the bootloader, as the build tools enforce them, not the chip’s full memory.

Can I still use it?

1 platforms

Arduino framework: Supported^[1]Official Arduino core.

As published by each project, checked weekly. A platform not listed has no published information here, which is not the same as no support.

Datasheets and documents

5 documents

Product documentation, ArduinoProduct page
Board datasheetDatasheet
SchematicsSchematic
Full pinoutPinout
Arduino Uno R4 WiFi product pageProduct page

Pinout

32 pins

Arduino Uno R3 headers^[1]. Same header positions as the Uno R3

Power
Ground
GPIO
Special
Not connected

Pin table (32 pins)

Power
Pin	Label	Kind	Functions
1	NC	Not connected
2	IOREF	Power	I/O reference voltage
3	RESET	Special	Reset (active low)
4	3.3V	Power
5	5V	Power
6	GND	Ground
7	GND	Ground
8	VIN	Power	Input voltage

Analog in
Pin	Label	Kind	Functions
1	A0	GPIO	ADC
2	A1	GPIO	ADC
3	A2	GPIO	ADC
4	A3	GPIO	ADC
5	A4	GPIO	ADC, I2C SDA
6	A5	GPIO	ADC, I2C SCL

Digital 0–7
Pin	Label	Kind	Functions
1	D0	GPIO	UART RX
2	D1	GPIO	UART TX
3	D2	GPIO	INT0
4	D3	GPIO	PWM, INT1
5	D4	GPIO
6	D5	GPIO	PWM
7	D6	GPIO	PWM
8	D7	GPIO

Digital 8–13, GND, AREF, SDA, SCL
Pin	Label	Kind	Functions
1	D8	GPIO
2	D9	GPIO	PWM
3	D10	GPIO	PWM, SPI SS
4	D11	GPIO	PWM, SPI MOSI
5	D12	GPIO	SPI MISO
6	D13	GPIO	SPI SCK, LED
7	GND	Ground
8	AREF	Special	Analog reference
9	SDA	GPIO	I2C SDA (same as A4)
10	SCL	GPIO	I2C SCL (same as A5)

Gotchas

2 known issues

Two chips, two firmwares. The RA4M1 runs your sketch; the ESP32-S3 runs Arduino's connectivity firmware and can be updated or reprogrammed separately.^[1]
5 V logic. I/O is 5 V. Sensors and modules that run at 3.3 V (most modern ones) need level shifting on their inputs.^[1]

What changed

From the specs

Since the Arduino Uno R4 Minima

Spec	Arduino Uno R4 Minima	Arduino Uno R4 WiFi
Wireless	—	Wi-Fi and Bluetooth LE via an on-board ESP32-S3
Launch price	US$20	US$27.50

Size and mechanical

0 facts

3D model (STEP)

History and use today

Editorial

History

Launched with the Minima in June 2023, the WiFi version added an ESP32-S3 co-processor and the LED matrix that made it a favourite for first IoT projects.^[1]

Still useful for

A friendly way into connected projects with Arduino Cloud while keeping shield compatibility.

Sources

4 sources

Spotted a mistake?

Reviewed by hand

Every report is read by a person and checked against a source before anything changes. Please link one if you have it.

Report a mistake