Pre-order your Raspberry Pi 5 today!

SparkFun RedBoard Plus

by Sparkfun

The SparkFun RedBoard Plus is an Arduino-compatible development board that has everything you need in an Arduino Uno with many extra perks.

The best part about the RedBoard Plus is that it utilizes the handy Qwiic Connect System which means no soldering or shields are required to connect it to the rest of your system!

SparkFun have applied every lesson they've learned about making a better Arduino Uno and created the RedBoard Plus! The SparkFun RedBoard Plus has all of the hardware peripherals you know and love: 22x Digital I/O pins with 6x PWM pins, 8x analog pins, UART, I2C, SPI, and external interrupts. They've also broken out the SDA, SCL and IOREF pins that showed up on the Arduino Uno R3 footprint, so the RedBoard Plus is compatible with future shields (if you choose to use them). Two additional analog pins are included for A6 and A7.

The USB-to-serial is now done with a reversible USB-C connector with through hole anchoring and the ubiquitous CH340G requiring fewer driver installs. The power portion of the RedBoard Plus has been optimized: it uses the AP2112 3.3V voltage regulator to provide up to 600mA to daisy chain multiple Qwiic boards and sensors, with full thermal and reverse circuit protection, and added extra decoupling capacitance to increase the sensitivity of the ADC readings. They've also increased the PTC from 500mA to 2A. They've decreased the brightness of the power LED, pin 13 LED, and the TX/RX LEDs from blinding to just perfect.

SparkFun have included 3.3V voltage translation and a Qwiic connector to the edge of the board to allow for quick and seamless connection to our ever-growing line of I2C based Qwiic products. Jumpers are included on the board for the A4 and A5 pins which are tied directly to the I2C bus and can be used to disconnect the logic level converters from the pins.

For more advanced users there's an I/O voltage switch also known as the "Red Squirrel" switch (because they are the one who petitioned for the mod). Now you can easily select the GPIO voltage between 3.3V or 5V with just your finger. This is extremely handy if you have a shield or 3.3V sensitive devices, such as an SPI interface, that needs protecting. Worried about accidentally flipping the switch? A piece of tape will lock it in place!

Clearly labeled PTH holes alongside the standard female headers. This makes it very easy to solder wires in place for a secure connection to make your project 'backpack safe' once you get it working. Solder pads are included on the bottom of the board for USB data pins D+/D- so you can embed your RedBoard Plus into a project and run an external USB connection. The height of the reset button has been increased. This doesn't sound like much, but everyone who's touched it loves the improvement.

The SparkFun RedBoard Plus can be programmed over a USB-C cable using the Arduino IDE: Just plug in the board, select "Arduino UNO" from the board menu and you're ready to upload code! You can power the SparkFun RedBoard Plus over USB or through the barrel jack. The on-board power regulator can handle anything from 7VDC to 15VDC.

The SparkFun Qwiic Connect System is an ecosystem of I2C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

Get Started with the SparkFun RedBoard Plus Guide


  • ATmega328P microcontroller with Optiboot (UNO) Bootloader
  • Input voltage
    • 7V to 15V via barrel jack
    • 5V via USB-C
  • Voltage Regulators
    • LM1117 adjusted to 5V
    • AP2112 for 3.3V
  • Built-in Resettable PTC Fuse 5V/2A
  • CH340G Serial-to-USB Converter
  • 3.3V to 5V Logic Level Switch
  • 22x Digital I/O Pins (6x PWM Outputs, 8x Analog Inputs, 1x UART, 1x I2C, 1x SPI)
    • 1x Qwiic Connector
    • A4/A5 Jumpers
  • 2x3 ISP Header
  • 32kB Flash Memory
  • 16MHz Clock Speed
  • All SMD Construction
  • R3 Shield Compatible
  • Improved Reset Button