Arduino Launches Its UNO R4 Boards with Surprise Features — Including an LED Matrix

Arduino has officially launched the Arduino UNO R4 Minima and WiFi, marking the biggest change to the popular development board footprint since its original launch — boasting of a more powerful 32-bit processor, new STEMMA QT/Qwiic connectivity, and a surprise on-board LED matrix display.

Arduino announced the Arduino UNO R4 back in March this year, taking the popular UNO footprint but giving it a complete overhaul on the hardware front. While retaining the unevenly-spaced pin headers of its predecessors in the UNO range, the R4 is the first model to boast a 32-bit processor: the Arm Cortex-M4, running at 48MHz. The Renesas RA4M1 system-on-chip (SoC) at the heart of the board also boasts 32kB of static RAM (SRAM) and 256kB of flash storage — up from 2kB and 256kB respectively on the UNO R3.

Other improvements made to the board design include a move to the more modern USB Type-C connector for data and power, an improved thermal design which allows the DC power input jack to handle up to 24V supplies, a 12-bit analog-to-digital converter (ADC), and a CAN bus for automotive projects and builds which require the use of multiple shield add-ons.

Despite all this, the hardware is as backwards-compatible as it can be — retaining the same 5V logic and pin-out as its predecessors, meaning the majority of projects and shields should port straight across so long as the software side has been updated.

The Arduino UNO R4 isn't a single board, however, but a pair of boards. The Arduino UNO R4 WiFi is the more expensive of the two, pairing its Renesas RA4M1 SoC with an Espressif ESP32-S3 to provide Wi-Fi and Bluetooth connectivity; for those who don't need a radio, or who will be adding an external LoRa radio or cellular modem to their projects, the Arduino UNO R4 Minima does away with the ESP32-S3 to lower the bill of materials.

An interesting feature which Arduino had opted to keep under wraps before the official launch of the Arduino R4 WiFi: a 12×8 LED matrix, located on the top of the device just below the SoC, as a built-in display. While it'll be of little use to anyone using shield add-ons on top of the board, it's a boon for standalone projects and those just starting out — allowing users to do something a little more exciting than blink a single LED without having to buy any additional hardware. This, however, is missing from the cost-reduced Minima.

In another shift for the company, the WiFi board also includes a STEMMA QT/Qwiic compatible connector for solderless expansion which doesn't require a full shield. SparkFun has already announced a bundle which includes the higher-end Arduino UNO R4 WiFi board and five of the company's most popular Qwiic breakout boards, including a display, potentiometer, and sensors.

The Arduino UNO R4 Minima and Arduino UNO R4 WiFi are now available to order priced at $20 and $27.50 respectively. SparkFun's Qwiic bundle is available on its own store, priced at $99.95 before volume discounts.