Seeed Studio XIAO SAMD21

The Seeed Studio XIAO SAMD21 is the original member of the popular XIAO family: a very small, breadboard-friendly Arduino-compatible development board built around the Microchip SAMD21G18 microcontroller.

Despite its tiny 21 × 17.8 mm footprint, this module provides a useful set of interfaces for compact embedded projects, wearable electronics, sensor nodes, small automation projects, data loggers, and educational Arduino projects.

The heart of the module is a 32-bit Arm Cortex-M0+ processor running at up to 48 MHz. It includes 256 KB Flash memory and 32 KB SRAM, which makes it a good step up from classic 8-bit Arduino boards while keeping power consumption low and the board size extremely compact.

Programming is supported through the Arduino IDE, PlatformIO, MicroPython, CircuitPython, and Zephyr. The USB-C connector is used for power and programming, so no external USB-to-serial adapter is required.

Key features

• Microchip SAMD21G18 microcontroller
• 32-bit Arm Cortex-M0+ processor, up to 48 MHz
• 256 KB Flash memory
• 32 KB SRAM
• Ultra-compact XIAO form factor: 21 × 17.8 mm
• USB-C connector for power and programming
• 11 digital I/O pins
• 11 analog-capable pins
• 10 PWM-capable pins
• 1 true DAC output on D0 / A0
• I²C, SPI, and UART interfaces
• SWD pads for advanced debugging and programming
• Onboard user LED, power LED, and serial TX/RX indicator LEDs
• Breadboard-friendly layout

Technical specifications

Important: The SAMD21 microcontroller uses 3.3 V logic. Do not connect 5 V signals directly to the GPIO pins.

This module can be used with our CANABLOX® development system. A suitable XIAO adapter board, such as CX-XIAO-S or CX-XIAO-MH, is required. It can also be added to our CANADUINO® PLC-300 V2 Programmable Logic Controller DIY kit to provide extended functionality.

For pinout, software setup, schematics, and additional documentation, please refer to the official Seeed Studio XIAO SAMD21 documentation:

Seeed Studio XIAO SAMD21 Wiki