Two New Arduino UNO R4 Boards: Minima and WiFi

    • by Clemens Valens
    • Reading time: 3 min

    The Arduino UNO R4 Minima and the Arduino UNO R4 WiFi have finally hit the shelves, introducing an exciting new chapter for Arduino enthusiasts and developers. Let’s explore the innovations these boards bring to the table.

    Arduino UNO R4 models

    Embracing Renesas Technology

    With the debut of the Portenta H7, Arduino embarked on a partnership with Renesas, featuring the ARM Cortex-M33 microcontroller. The UNO R4 Minima and WiFi continue this legacy with the RA4M1 microcontroller, a 32-bit ARM Cortex-M4 processor that elevates the boards' capabilities with its 48 MHz clock speed, 32 KB RAM, and 256 KB flash memory. This adoption signifies Arduino's deeper integration into the Renesas ecosystem.

    The RA4M1's support for up to 5 V power supplies sets it apart in the ARM microcontroller world, making these boards a powerful extension of the Arduino UNO R3 legacy.

    Renesas RA4M1 microcontroller on UNO R4
    Powering up innovation: The Renesas RA4M1 microcontroller on the Arduino UNO R4.

    UNO R4's Enhanced Capabilities

    Moving from an 8-bit to a 32-bit microcontroller has broadened the UNO R4's horizon, introducing a richer set of features while maintaining the simplicity and reliability Arduino is known for. The UNO R4 Minima maintains the design elegance of the R3, with the UNO R4 WiFi packing more into its frame with an LED matrix and an ESP32-S3-MINI-1 module.

    The breadth of peripherals supported by the RA4M1 microcontroller, including CAN bus and USB 2.0, reflects a significant leap in functionality. The transition to a USB-C port modernizes the boards for current and future projects.

    Connectivity and Communication

    The RA4M1 enhances board communication with dual SPI and I²C ports, alongside four serial communication interfaces. This versatility opens new avenues for project development, with the UNO R4 models offering extensive connectivity options.

    Advancing Analog Capabilities

    The UNO R4 series excels in analog performance, featuring a 12-bit DAC, an operational amplifier, and a comparator, far surpassing the PWM limitations of previous models. This advancement underscores Arduino's commitment to providing tools for sophisticated analog applications.

    Software Development and Support

    Integrating a new microcontroller necessitates advancements in the Arduino IDE and libraries, setting the stage for a richer development environment that fosters innovation and growth.

    SWD connector on UNO R4 Minima
    Streamlined troubleshooting with the SWD interface on the UNO R4 Minima.

    Debugging capabilities on the UNO R4 Minima and the integrated CMSIS-DAP debugger on the UNO R4 WiFi model significantly enhance the development experience, allowing for more complex and reliable projects.

    Exclusive Networking and Display Features

    The UNO R4 WiFi sets itself apart with its Wi-Fi & Bluetooth module and an integrated LED matrix, offering unparalleled opportunities for IoT development and interactive projects.

    Dual I²C Ports for Expanded Connectivity

    With two I²C ports, the UNO R4 WiFi ensures seamless integration with a wide array of devices, supported by a Qwiic-compatible connector for easy connection to 3.3 V and 5 V peripherals.

    Revolutionary Power Supply Design

    The transition to a switching regulator in the UNO R4 series facilitates a wider voltage input range and higher efficiency, marking a significant improvement over the linear regulators of previous models.

    Power regulation on UNO R4
    Enhanced power management on the Arduino UNO R4.

    Forward-Looking Conclusion

    The Arduino UNO R4 Minima and WiFi not only continue the legacy of the UNO R3 but also push the boundaries of what's possible with Arduino, offering more power, more features, and more opportunities for creativity and innovation.

    The Next Step in Arduino's Evolution

    The enhanced debugging features and forward-thinking capabilities of the UNO R4 series represent a significant milestone in Arduino's journey, setting a new standard for development tools and opening up new possibilities for makers and professionals alike.

    arduino uno r4 wifi
    Arduino R4 minima


    * This overview is informed by the version 0.8.7-ea (Early Access) of the Arduino Renesas Boards package, anticipating future developments and enhancements.

    ** A custom program for the UNO R4 WiFi's LED matrix was developed before the official library release, available on GitHub.



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