The Arduino Leonardo is a microcontroller board based on the ATmega32u4. It is the latest addition to the Arduino family.This chip has about the same amount of flash, RAM and capability as the ATmega328 found in the arduino UNO
It has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, a power jack, an ICSP header, and a reset button.
It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.
The Leonardo differs from all preceding boards in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Leonardo to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port. It also has other implications for the behavior of the board;these are detailed on the getting started page[http://arduino.cc/en/Guide/ArduinoLeonardo] for this board. This version of the Leonardo comes with all headers attached for an easy-to-use experience.
Notics: This board is only supported in the latest Arduino IDE 1.0.1 so you will also need to update the IDE.
Arduino Leonardo Microcontroller Related Projects:
This project is essentially an NFC reader that you stick on your door. Every time you approach the door the circuit makes noise; the only way to stop the noise is to scan an NFC tag affixed to your keys against the reader. Thus, the noise means you won't ever forget your keys again! Let's dive in.
The things you need:
(order as many as you want to have to put on key rings)