Feature: 1. Stable Working: Equipped with independent crystal oscillator, the micro controller allows for operation with more stability. 2. More Interface: Compared to the for Femto, the micro controller board for XIAO has been added with SPI interface, very useful. 3. Better Utility: USB type C interface has better utility than USB mini, so it can be applied to arm system, USB development, etc. 4. Practical Using: Added power supply PAD enables to be powered by lithium battery and help to achieve truly wearable functions. 5. Strong Function: User LED is also added to make it much easier for program debugging, making the microcontroller more functional. Specification: Item Type: Microcontroller Material: PCB Working Voltage: DC 5V CPU: ARM Cortex-MO+ CPU (SAMD21G18) 48MHZ Storage: 256KB Flash, 32KB SRAM I/O Pins: 14 pins. 11 analog and digital pins, 1 for DAC function and 10 for PWM function. 1 I2C pin. 1 UART pin. 1 SPI pin. Interface: USB Type C power supply and download interface, 1 user light, 1 power light, 2 download lights. Function: Used to control the arm single chip microcomputer system. Applicable Scenarios: For MCU, arm system, wearable device, USB development. . Package List: 1 x Mainboard2 x Pin Header Note: Do not use in a humid environment.