Adafruit Gemma - Miniature Wearable Arduino-like Electronic Platform Super small, only 1.1" / 28mm diameter and 0.28" / 7mm thick. Easy-to-sew or solder pads for embedding in your wearable project Ultra low power, draws only 9 mA while running New Version 2 includes micro USB and a power switch! 3 GPIO - The 3 independent IO pins have 1 analog input and 2 PWM output as well.