In the world of modern electronics, few things are as timeless and noteworthy as the Arduino Uno ‎Rev3 with its socketed Atmega328 DIP chip. This board helped launch the maker movement we know ‎today by tearing down barriers to DIY electronics projects when it was first released in 2010 – you’d be ‎hard-pressed to find an embedded programmer today that hasn’t wielded this board at some time ‎during their tenure. Therefore, the launch of a new UNO board is certainly something to make one ‎stand and take notice!

Building upon over a decade of technological developments, Arduino has now released not one but ‎two new boards to continue this legacy: the Arduino UNO R4 Minima and UNO R4 WiFi!

The Arduino UNO R4 Minima maintains the well-established UNO R3 form factor and pinout, along ‎with 5V logic, making it directly compatible with all your favorite Arduino Shields. However, this new ‎UNO is packing much more horsepower than the classic UNO. Fitted with a 48MHz 32-bit Cortex® M4 ‎Renesas microcontroller featuring 256kB flash memory and 32kB RAM, this board is well suited for the ‎most demanding of embedded applications. Additionally, the R4 features a modern USB-C port for ‎programming and power that even allows the new UNO to act natively as an HID keyboard or mouse ‎and an onboard SWD connector that supports advanced debugging capabilities. Finally, the UNO R4 ‎now supports input voltages ranging from 6-24VDC on the VIN pin or via the DC barrel jack.

The Arduino UNO R4 WiFi sports all the features of the Minima, save for the SWD port, which is ‎replaced by an error-catching mechanism that detects runtime crashes and provides detailed ‎explanations and hints about the code line causing the crash, so you are not left without debugging ‎support. In addition to the Minima’s feature set, the WiFi board sports an ESP32-S3 module, which ‎provides the namesake WiFi functionality as well as Bluetooth connectivity. Further expanding the ‎connectivity is a Qwiic connector for a solder-free, daisy-chainable interface with I2C expansion boards. ‎Similar to the recent Arduino Giga R1 WiFi, the UNO R4 WiFi also features an onboard RTC that can be ‎powered independently of the remainder of the board, allowing for timekeeping during deep sleep or ‎complete power-down states. And finally, you will notice the board features a user-controlled 12×8 ‎red LED matrix, often eliminating the need for an additional display shield.

Overall, the UNO R4 Minima and WiFi greatly expand the functionality and features of the classic UNO ‎R3, presenting a new horizon for makers. However, for those closely tied to the UNO R3, there are no ‎plans to discontinue the board, so compare all your options for an Arduino UNO below, and choose the ‎board best suited to your next project.