The Arduino is based on the microcontrollers from Atmel. Here are current Arduinos available (the architecture is open source, and anyone can build their own “Arduino” based on the technical specs that are available for download from the official Arduino website).
- Duemilanove: “Duemilanove” means 2009 in Italian and is named after the year of its release. The Duemilanove is the latest in a series of USB Arduino boards. It is based on the ATmega328 and has 14 digital input/output pins (of which 6 can be used as PWM outputs) and 6 analog inputs.
- MEGA: The Arduino Mega is based on the ATmega1280. It has 54 digital input/output pins (of which 14 can be used as PWM outputs) and 16 analog inputs.
- Mini: The Arduino Mini is a small microcontroller board based on the ATmega168 (surface-mounted), intended for use on breadboards or when space is at a premium.
- Nano: The Arduino Nano is a small, breadboard-friendly board based on the ATmega328 (Arduino Nano 3.0) or ATmega168 (Arduino Nano 2.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package.
- Bluetooth: The Arduino BT is an Arduino board with built-in bluetooth module, allowing for wireless communication. It features a surface-mounted ATmega168.
- LilyPad: A stripped-down, circular Arduino board designed for stitching into clothing and other fabric/flexible applications. It can be sewn to fabric with conductive thread. Lilypads are available on versions based on the ATmega168 or the ATmega328.
** This post was written when one could count on both hands the number of Arduino boards and clones available. It will be hard to keep up with the growing variety of Arduino boards, but this Arduino search link should have the latest boards and accessories at the time you are reading this.