It's finally there: the shrimp!

This is where the shrimp comes in. It’s a very, very minimal Arduino-compatible circuit meant to control all the pins on an ATMega328. The components only cost about £1.40 ($2.25 USD) when bought in volume, making it perfect for teaching a class or workshop on the Arduino and giving each student a circuit to take home.

The basic circuit is just an ATMega328 – the same microcontroller used in the Arduino Uno – with a few caps, resistors, and a 16 MHz crystal. It’s a very bare-bones system, but once built and programmed provides all the functionality of a $25 Arduino.