Popular development board scales performance with new 32-bit versions

Arduino has launched its next-generation UNO board, a notable revision of its 8-bit technology. Powered by a 32-bit microcontroller, the new UNO R4 comes in two versions: the basic UNO R4 Minima and comprehensive UNO R4 WiFi, meeting the budgetary and creative needs of the maker community.

Preserving the standard form factor, shield compatibility and 5V power supply of the UNO R3, the UNO R4 adds a 32-bit microcontroller with up to 16x the clock speed, memory, and flash storage with the integration of the RA4M1 processor from Renesas.

Based on an Arm Cortex-M4 core, the RA4M1 microcontroller on the UNO R4 provides a 48MHz clock speed for higher processing power. To accommodate more complex projects, the UNO R4 has 32kB of SRAM and 256kB of flash memory. The Arm Cortex-M4 core features an FPU, which improves certain applications' performance. Software scalability is also supported on the new board, permitting easy upgrades for projects made with UNO R3 or Leonardo.

Requests from the Arduino community see the USB port upgraded to USB-C and the maximum power supply voltage increased to 24V with an enhanced thermal design. The board supplies a CAN bus, enabling users to minimise wiring and execute different tasks in parallel by connecting multiple shields and two SPI and two I2C serial ports. Finally, the new board includes a 12-bit analog DAC and operational amplifier.

Keeping the pinout, voltage and form factor unchanged from the UNO R3 ensures maximum hardware and electrical compatibility with existing shields and projects while permitting the UNO R4 boards to be a high-performance drop-in replacement.

The UNO R4 WiFi version comes with an Espressif ESP32-S3 module for Wi-Fi and BLE connectivity. The bright 12x8 red LED matrix is excellent for creative projects utilising animations or plotting sensor data without extra display hardware. With a wide assortment of compatible modules that can be connected through the Qwiic I2C connector, combined with the large ecosystem of shields for UNO already in the market, UNO R4 WiFi provides an unprecedented plug-and-play experience that enables the creation of projects without soldering, breadboards or manual wiring. For more advanced uses, extra pins are also to turn off the microcontroller while keeping the RTC powered by an external buffer battery.

For makers seeking a boost in processing power without the additional features, the UNO R4 Minima provides a cost-effective option. With the HID over USB capability, makers can simulate a mouse or a keyboard to create quick and innovative interfaces with minimal effort.

"We are excited to make our technology more accessible to a broader base of customers as we continue to collaborate with Arduino," comments Chris Allexandre, SVP, CSMO and head of Global Sales and Marketing at Renesas. "After the success of the Portenta C33, we are now launching the next-generation UNO R4 using our 5 V 32-bit Arm Cortex M4-based microcontrollers. We believe this iconic board will provide an enhanced user experience to a wide range of customers."

Massimo Banzi, co-founder and chairman at Arduino, believes that the UNO R4 represents a new chapter to the UNO story, saying: "With the ever-changing needs of our community and technological advancements, even the most popular UNO R3 must evolve, though we have no plans to discontinue the board. In close collaboration with our partners, Renesas and Espressif, we believe the UNO R4 is the most versatile maker board on the market. Using the WiFi option, users can connect to the Arduino Cloud or other platforms to easily create connected projects."