Gumstick-sized Arduino-compatible board

Design by: 5923

This is an AVR development board the size of a USB memory stick. It works perfectly with the Arduino Leonardo firmware. Parts: ATmega32u4 TQFP44, 16 MHz through-hole crystal, 0805 resistors (22 ohm x2, 1k ohm x1), and an 0805 1 uF capacitor. Optionally, a button for reset and an Adafruit Neopixel (the little square surface mount ones). To drive the Neopixel, pin PI is the data input, and PO is the data output (to chain to more Neopixels). You may need to glue a credit-card-thickness square of plastic to the bottom of the USB plug, to get a good connection; PCBs aren't quite thick enough.