Arduino's ubiquity and simplicity has led to a gigantic surge in the use of microcontrollers to build programmable electronics project. Despite the low cost of Arduino, you're still committing about $30 worth of hardware every time you build a project that has an Arduino inside. This is where Adafruit's Trinket comes in. Arduino-compatible, one-third the price, and low-power, the Trinket lets you make inexpensive and powerful programmable electronic projects. Written by one of the authors of Adafruit's Trinket documentation, Getting Started with Trinket gets you up and running quickly with this board, and gives you some great projects to inspire your own creations.
