With no plans to discontinue the popular UNO R3, the UNO R4 will come in two versions – UNO R4 WiFi and UNO R4 Minima.
The UNO R4 is powered by the Renesas RA4M1 32-bit microcontroller based on the Arm Cortex-M4 core, which provides a significant boost in processing power, memory, and functionality. The WiFi version comes with an Espressif S3 WiFi module, that will help to expand creative opportunities for makers, educators, and hobbyists according to Arduino.
The UNO R4 maintains the same form factor, shield compatibility, and 5V operating voltage as its predecessor with software compatibility also a priority, with most existing libraries and examples working seamlessly on the new board.
The UNO R4 WiFi features Wi-Fi and Bluetooth Low Energy connectivity, while the UNO R4 Minima provides a cost-effective option for those seeking the new microcontroller without additional features. Support for other Renesas microcontrollers, such as the RL78/G22 and G23, has also been added to the Arduino IDE.
According to Massimo Banzi, co-founder and chairman of Arduino, the UNO R4 can be seen as a new chapter in the UNO story and the “perfect way to move forward, leveraging the latest available technology.”
“While maintaining the UNO R3 in our product line-up, we collaborated closely with our partners Renesas and Espressif to create the most compatible and powerful maker board on the market,” said Fabio Violante, CEO at Arduino. “I’m eager to see the incredible projects the community will develop, particularly with the UNO R4 WiFi.”
The Arduino UNO R4 boasts a 3x performance increase over the UNO R3 and , in addition, SRAM has been upgraded from 2kB to 32kB, and flash memory from 32kB to 256kB to support more complex projects.
Responding to community feedback, the USB port is now USB-C, and the maximum power supply voltage has been raised to 24V with an enhanced thermal design. The board includes a CAN bus and an SPI port, enabling users to reduce wiring and perform parallel tasks by connecting multiple shields. A 12-bit analogue DAC is also provided on the new board.
To ensure backwards compatibility with existing code examples and tutorials, significant efforts are being made on the software side of the UNO R4.
Popular Arduino libraries are being optimised, and in most cases, they will work out-of-the-box. However, some libraries that were previously optimised for the AVR architecture in R3 may require porting to the new Renesas architecture. To assist with the transition, Arduino will provide a public list of such libraries, along with links to alternative options.
In order to encourage library developers to port their low-level code to the Renesas architecture, an early adopter programme has been launched.
The Arduino UNO R4 is set for release in late May.
