Take a look at Seeeduino XIAO. It'ss the smallest member of the Seeeduino family. Seeeduino XIAO still carries the powerful CPU-ARM® Cortex®-M0+(SAMD21G18) which is a low-power Arduino microcontroller. This little board has good performance in processing but needs less power. As a matter of fact, it is designed in such a tiny format, it can be used for Arduino wearable devices and small projects.
Apart from the powerful CPU, Seeeduino XIAO is excellent in many other functions. It has 14 GPIO PINs, which can be used for 11 analog PINs, 11 digital PINs, 1 I2C interface, 1 UART interface, and 1 SPI interface. Some PINs have various functions, A1/D1 to A10/D10 Pins have PWM functions and Pin A0/D0 has a function of DAC which means you can get true analog signals, not PWM signals when you define it as an analog pin, that’s why 14 GPIO PINs can realize more I/O PINs and interfaces. Moreover, Seeeduino XIAO supports the USB Type-C interface which can supply power and download code. There are power pads at the back of the XIAO which support battery and make it designed for wearable devices to become realistic. Except for the power LED, we add a user LED on board for your better coding experience. Usually a Dev. Board as small as this size will use the chip’s inner crystal oscillator for time fixing, in order to make the clock more accurate, Seeeduino XIAO layouts an extra 32.768KHz to make the clock more stable.
Seeeduino XIAO is perfectly compatible with Arduino IDE, you can easily develop some small projects with the help of the large and comprehensive Arduino library. So get one and you will soon love it!
Attention: All the I/O pins are 3.3V, please do not input more than 3.3V, otherwise, the CPU may be damaged.