Arduino UNO R4 Compatible Board – Minima & WiFi Clone Development Kit

Arduino UNO R4 Compatible Board — Minima and WiFi Clone

This Arduino UNO R4-compatible board runs the Renesas RA4M1 ARM Cortex-M4 at 48MHz — a significant step up from the ATmega328P’s 16MHz — with 256KB flash, 32KB SRAM, and a 12-bit DAC output. The Minima variant keeps the classic Uno footprint and header layout; the WiFi variant adds an ESP32-S3 co-processor providing 2.4GHz WiFi and Bluetooth 5 alongside the RA4M1. Both are programmed from the Arduino IDE using the Arduino UNO R4 board package.

• Renesas RA4M1 Cortex-M4 at 48MHz — 3x faster than the ATmega328P
• 256KB flash, 32KB SRAM — 16x more RAM than the Uno R3
• 12-bit DAC — true analogue voltage output on pin A0
• USB-C connector — replaces the USB-B of the R3
• WiFi variant: ESP32-S3 co-processor — 2.4GHz WiFi and Bluetooth 5
• Uno R3 shield compatible header layout

Is the UNO R4 backward compatible with UNO R3 shields?

Yes for the header pin layout — digital, analogue, and power pins are in the same positions as the R3. Shields designed for 5V operation work directly. A small number of shields that directly configure ATmega328P registers will not work on the RA4M1 — shields using standard Arduino library calls are unaffected.

Does the WiFi variant replace the R3 for IoT projects?

Yes. The ESP32-S3 handles WiFi and Bluetooth while the RA4M1 runs the main sketch — no separate ESP8266 shield or WiFi module needed. The Arduino WiFiS3 library provides a familiar API for connecting to WiFi networks and making HTTP/HTTPS requests.

Best for

IoT sensor hubs, WiFi-connected data loggers, Bluetooth HID devices, high-speed signal processing, audio output via DAC, upgrading existing Uno R3 projects to faster hardware, and university electronics courses transitioning to ARM microcontrollers.

Why Kunkune

Shipped from UK stock. 60-day returns, no minimum order. Same-day dispatch before 2pm.

Buying in bulk? For orders of 10+ units, contact us for trade pricing.