Itsy Bitsy 32u4

Adafruit Itsy Bitsy 32u4 are Arduino-compatible microcontroller boards based on the low-power Microchip Technology ATmega32U4 8-bit MCU. These microcontroller boards are available in 3V, 8MHz, and 5V, 16MHz versions and have six power pins, six analog and digital pins, and 17 digital pins. The Itsy Bitsy 32u4 features USB uploading and debugging, a micro-USB jack for power, onboard red LED pin, 23 GPIOs, and a reset button. The 3V version has two special pins, the VHigh pin that drives NeoPixels and a digital pin connected to a level shifter with a high logic output. The 5V version features an onboard 5.0V power regulator with 150mA output capability and ultra-low dropout.