Seeed Studio XIAO SAMD21 Plus

The original XIAO formula, now with fewer arguments about running out of pins. The SAMD21 Plus keeps the tiny 21 × 17.8 mm footprint, then adds 16 extra SMD GPIOs, onboard Li-ion battery management and proper Reset and Boot buttons.

Why You Want It

You get the friendly, well-supported SAMD21 platform in a board small enough for wearables, compact robots and custom carrier boards. Native USB makes it particularly handy for keyboards, macro pads, MIDI controllers and other projects that enjoy pretending to be a USB device.

Specifications

• MCU: Microchip ATSAMD21G18A, 32-bit ARM Cortex-M0+ at up to 48 MHz
• Memory: 256 KB Flash and 32 KB SRAM
• GPIO: 30 total, including 27 digital and 11 analogue pins
• Interfaces: 2× I²C, 1× UART, 1× SPI, 1× I²S and 1× DAC
• Extra I/O: 16 additional GPIOs on 1.27 mm SMD castellations
• USB: USB Type-C with native USB device support
• Battery Management: Onboard PMIC with Li-ion charging and BAT-to-3V3 backflow protection
• Onboard Controls: Reset button and Boot button
• Indicators: User LED, power LED, TX/RX indicators, programmable WS2812 RGB LED and charge LED
• Input: 5 V by USB Type-C or BAT input
• Dimensions: 21 × 17.8 mm (still properly tiny)
• Operating Temperature: -40°C to 85°C
• Software Support: Arduino, PlatformIO, MicroPython, CircuitPython, TinyGo, Zephyr and more

What's in the Box*

• 1× Seeed Studio XIAO SAMD21 Plus
• 2× 7-pin headers

Disclaimer

*Battery and USB cable are not included. It may have gained 16 extra GPIOs, but it has not gained the ability to label your jumper wires for you.

Still Here?

Either you are counting GPIOs twice (respect) or your current board has finally run out. Add one to the bench and give the next tiny project some room to grow.