Seeed’s latest entry in their Arduino-based Seeeduino family measures out at a tiny 23.5mm x 17.5mm is driven by Microchip’s SAM D21 microcontroller and can be integrated into nearly any project from robots to wearables. The Seeeduino XIAO is a breadboard-friendly development board that’s similar to Adafruit’s Trinket M0, only it comes with a more advanced processor (ATSAMD21G18 vs. ATSAMD21E18), adds more GPIOs, and is significantly smaller in size.
Beyond the SAM D21 MCU, which features a 32-bit Arm Cortex-M0+ CPU (256KB of Flash, 32KB of SRAM), the Seeeduino XIAO is outfitted with 14 GPIOs, 11 analog pins, 11 digital pins, 10 PWM pins, and one DAC output pin. It also sports I2C, UART, and SPI interfaces, along with a USB Type-C port, several LEDs, reset button, power pads (for battery power), and has an operating voltage of 3.3V.
The back of the Seeeduino XIAO includes four power pads designed for batteries, which makes the development board ideal for wearables and other projects that don’t require connected power. Seeed also states they have added an extra 32.768KHz to the MCU’s internal crystal oscillator for time fixing with added stability and accuracy.
Programming is kept simple as well, as the board makes use of the Arduino IDE and its extensive library. Seeed is currently offering the Seeeduino XIAO on its product page, which retails for just $4.90, making it one of the cheapest SAM D21-based boards on the market at this point.