UNO R4 Minima 32-bit MCU Compatible Development Board

Specifications

• Board: UNO R4 Minima
• Microcontroller: Renesas RA4M1 (Arm® Cortex®-M4)
• Operating Voltage: 5V (Standard UNO logic)
• Input Voltage (VIN): 6-24V (Improved wide range)
• Clock Speed: 48 MHz
• Memory: 256 kB Flash / 32 kB SRAM
• Digital I/O Pins: 14 (6 PWM)
• Analog Input Pins: 6 (14-bit resolution capability)
• DAC: 1 x 12-bit (True Analog Output)
• Communication: UART, SPI, I2C, CAN Bus
• USB Connector: USB-C (Power & Programming)

Applications

• Human Interface Devices (HID): Build custom macro keypads, game controllers, or assistive mouse devices natively via USB.
• Automotive & Industrial: Use the built-in CAN Bus (Controller Area Network) to read vehicle diagnostics or communicate with industrial actuators (Requires transceiver).
• Audio Projects: Utilize the 12-bit DAC to generate high-quality sound waves or signals without external modules.
• IoT Edge Computing: Run lightweight Machine Learning models (TinyML) directly on the board.

Features:

• Hardware Compatibility: Retains compatibility with the UNO form factor and 5V operating voltage, similar to the UNO R3. Works seamlessly with existing shields and projects.
• Enhanced Peripherals: Includes a 12-bit DAC, CAN BUS, and OP AMP, expanding the range of on-board peripherals.
• Wider Input Voltage Range: Supports power supplies ranging from 6V to 24V, providing more flexibility for various applications.
• SWD Connector: Easily connect an external debugger to monitor the inner workings of your code and hardware.
• HID Support: Built-in HID (Human Interface Device) support allows it to simulate a mouse or keyboard.

Project Evolution

• The Prerequisites: If you've mastered the classic LED Blink and basic sensor reading on an UNO R3, you are ready for the Minima.
• The Upgrade: This board unlocks Real-time Signal Processing.

• Scenario: On an R3, calculating FFTs (Fast Fourier Transforms) for audio visualization is slow and laggy.
• With R4 Minima: The 32-bit core and DSP instructions crunch audio data in real-time, allowing you to build responsive music visualizers or voice-controlled remotes.

• Effort Level: Intermediate. The code is Arduino-compatible, but you'll have more registers and power to manage.

Virtual Technician: Wiring & Safety ⚠️

• Probots Logic-Safe: Unlike many 32-bit boards (like ESP32) which are 3.3V, the UNO R4 Minima allows 5V logic on GPIO pins. This means your old motor drivers and LCD shields work safely without level shifters.
• Pinout Note: The SPI pins are located on the ICSP header, just like the R3. Ensure your shields use the ICSP header for SPI communication.
• Power Warning: While VIN supports up to 24V, we recommend keeping it under 12V if drawing significant current to prevent thermal throttling of the regulator.

Package includes:

• 1 x UNO R4 Minima 32-bit MCU Compatible Development Board

Frequently Asked Questions (Technical FAQs)

• Is the UNO R4 Minima compatible with my old UNO R3 shields?
  Yes, it maintains the same form factor and 5V logic voltage, making most shields compatible.
• Does this board use the exact same ATmega328P chip?
  No, it uses a much more powerful 32-bit Renesas RA4M1 chip.
• Do I need to install a new Board Manager in Arduino IDE?
  Yes, you must install the "Arduino UNO R4 Boards" package via the Board Manager.
• Can I use the same code from my R3 on the R4?
  Most code works seamlessly, but libraries specifically accessing AVR hardware registers will need updates.
• Does the R4 Minima have WiFi or Bluetooth?
  No, the Minima is the offline version. For wireless, check the UNO R4 WiFi.
• What is the maximum voltage I can supply to the VIN pin?
  The R4 Minima supports a wide input range of 6V to 24V.
• Does it support HID (Keyboard/Mouse) emulation?
  Yes, the USB-C port supports native HID, allowing it to act as a keyboard or mouse.
• How many hardware UART (Serial) ports does it have?
  It has one dedicated hardware UART (Serial1) on pins 0 and 1, plus the USB-Serial.
• Is the ADC resolution higher than the UNO R3?
  Yes, the default is 10-bit, but you can configure it up to 14-bit resolution.
• Does it include a USB-C cable?
  This listing is for the board only; a USB-C cable is sold separately.
• What is the current limit per I/O pin?
  We recommend keeping the load under 8mA per pin (standard for this architecture), which is lower than the AVR's 20mA.
• Can I use the CAN Bus directly?
  The MCU has a CAN controller, but you need an external CAN Transceiver module to connect to a bus.
• Is there a built-in DAC?
  Yes, pin A0 can be used as a 12-bit Digital-to-Analog Converter output.
• How do I troubleshoot upload errors?
  Double-tap the reset button to enter bootloader mode if the port isn't recognized.
• Does it have an EEPROM?
  It has 8kB of Data Flash which acts like EEPROM for storing non-volatile data.
• Is the pinout identical to UNO R3?
  Physically yes, but some internal pin mappings differ. Always use standard Arduino API calls (digitalWrite) for portability.
• Can it drive a servo motor directly?
  Yes, using the standard Servo library, powered via the 5V pin (if using external power).
• Does it support interrupts on all pins?
  Most digital pins on the R4 support interrupts, offering more flexibility than the R3's two pins.
• What is the "SWD" header for?
  The SWD header allows advanced debugging using a J-Link or similar debugger.
• Is this board suitable for beginners?
  Absolutely. It offers the same ease of use as the R3 but with more room to grow.