Arduino has announced two newest boards, the Arduino Uno R4 WiFi and the Arduino Uno R4 Minima. As you can probably guess from the name, the R4 WiFi has onboard Wi-Fi thanks to his ESP32-S3 coprocessor. Minima has the same Arm Cortex M4 processor, but omits the ESP32-S3.
Will these boards beat the $8 Raspberry Pi Pico W or the $4 Raspberry Pi Pico? We’ll find out once we get the units for review.
Arduino Uno R4 WiFi
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The $27 Arduino R4 WiFi takes the familiar Arduino Uno layout but improves it slightly. The layout is the same, but instead of the large Atmel ATMEGA328P occupying the board, a 12 x 8 LED matrix is displayed. This matrix is used to display images and scroll text in much the same way as the micro:bit. A 48 MHz Renesas RA4M1 Arm Cortex-M4 CPU is used instead of a 16 MHz ATMEGA328P microcontroller for better performance on paper. Not sure yet how that will translate to your project.
But the Arduino R4 WiFi is more than just flashing lights. The onboard ESP32-S3 is a capable microcontroller in its own right, providing both Wi-Fi and Bluetooth for the Uno R4 WiFi. This isn’t his first Arduino with Wi-Fi, but the IoT (Internet of Things) is clearly taking hold, so a welcome addition to the R4. Like many previous Arduinos, the Uno R4 WiFi can also be a USB HID device. This means you can design your own inputs and use the Uno R4 as an interface. Create custom keyboards, game controllers, and assistive technologies with just a few lines of code and a little soldering.
An unusual but pleasant surprise is the onboard Qwiic connector. The connector is electrically compatible with Adafruit’s Stemma QT, Pimoroni’s QW/ST and of course SparkFun’s many sensors and components that use Qwiic connectivity. This means you can easily connect the best Stemma QT/Qwiic and QW/ST components for quick and simple projects.
| microcontroller | Renesas RA4M1 (Arm Cortex-M4 @ 48 MHz) |
| row 1 – cell 0 | ESP32-S3 up to 240MHz |
| memory | RA4M1: 256KB Flash, 32KB RAM |
| row 3 – cell 0 | ESP32-S3: 384kB ROM, 512kB SRAM |
| GPIOs | 14x digital I/O |
| row 5 – cell 0 | 6 x analog inputs |
| row 6 – cell 0 | 1 x 12-bit DAC |
| row 7 – cell 0 | 6 x PWM |
| row 8 – cell 0 | 4x UART, 1x I2C, 1x SPI, 1x CAN |
| row 9 – cell 0 | 1x Qwiic/Stemma QT/QWST connector |
| Connectivity | Wi-Fi® support via 802.11 b/g/n standard (Wi-Fi 4) |
| Row 11 – Cell 0 | bluetooth 5 |
| Power | 6 to 24V input voltage |
| Row 13 – Cell 0 | USB C |
| Row 14 – Cell 0 | 5V logic level (ESP32-S3 is 3.3V) |
| Row 15 – Cell 0 | 8 mA DC current per I/O pin |
| size | 68.85×53.34mm |
Arduino Uno Minima
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If you don’t need Wi-Fi or Bluetooth and want to save $7, Minima is the new base-level Arduino for your project. Basically, this is the same board as the Uno R4 WiFi, omitting the Qwiic connector and offering the same GPIO options. This omission is very disappointing, but we have to cut costs to get the $20 price.
| microcontroller | Renesas RA4M1 (Arm Cortex-M4 @ 48 MHz) |
| memory | RA4M1: 256KB Flash, 32KB RAM |
| GPIOs | 14x digital I/O |
| row 3 – cell 0 | 6 x analog inputs |
| row 4 – cell 0 | 1 x 12-bit DAC |
| row 5 – cell 0 | 6 x PWM |
| row 6 – cell 0 | 4x UART, 1x I2C, 1x SPI, 1x CAN |
| Power | 6 to 24V input voltage |
| row 8 – cell 0 | USB C |
| row 9 – cell 0 | 5V logic level (ESP32-S3 is 3.3V) |
| row 10 – cell 0 | 8 mA DC current per I/O pin |
| size | 68.85×53.34mm |
of Arduino Uno R4 WIFI and Arduino Uno R4 Minimalist Both are available directly from Arduino.
