Seeeduino XIAO - Arduino Microcontroller - SAMD21 Cortex M0+

Key Features

Powerful CPU: ARM® Cortex®-M0+ 32bit 48MHz microcontroller(SAMD21G18)-
with 256KB Flash,32KB SRAM
Flexible compatibility: Compatible with Arduino IDE
Easy project operation: Breadboard-friendly
Small size: As small as a thumb(20x17.5mm) for wearable devices and small projects.
Multiple development interfaces: 11 digital/analog pins, 10 PWM Pins, 1 DAC output, 1 SWD Bonding pad interface, 1 I2C interface, 1 UART interface, 1 SPI interface.

Specification

CPU: ARM Cortex-M0+ CPU(SAMD21G18) running at up to 48MHz
Storage: 256KB Flash,32KB SRAM
I/O PINs: 14 GPIO PINs,11 analog PINs, 11 digital PINs, 1 DAC output Pin
Interface: 1 I2C interface,1 UART interface, 1 SPI interface
Power supply and downloading interface: USB Type-C interface
LEDs: 1 user LED, 1 power LED, two LEDs for serial port downloading
Reset button: two reset button short connect to reset
Power Pads: For the battery power supply
Software compatibility: Compatible with Arduino IDE
Projection cover for protecting the circuit
Dimensions: 20x17.5x3.5 mm

Typical Application

Wearable devices
Rapid prototyping (directly attached to the expanded PCB as a minimal system)
Perfect for all the projects need mini arduino
DIY keyboard
USB development (USB to multi-channel TTL/USB host mode, etc.)
A scenario where you need to read multiple mock values The DAC output

Sources :
https://files.seeedstudio.com/wiki/Seeeduino-XIAO/res/Seeeduino-XIAO-HDK.pdf