Arduino Leonardo released
Source: Arduino.cc The long awaited Arduino Leonardo is now finally available in commercial quantities. It contains a 16 MHz Atmega32U4, which also takes care of USB communication with the host. On the Arduino Uno, a separate chip is required to take care of this. The simpler layout and smaller number of components means that the Leonardo is around £3 cheaper than the Uno. It is available with or without headers for the shields.
USB integration allows the Leonardo both to emulate a serial port and to act as a human interface device (HID). It can appear to be a either a mouse or a keyboard when connected to a PC, enabling users to control the computer through the Arduino; this capability allows the Arduino to be used, for example, as the controller in an assistive device.
The Leonardo has 20 digital inputs and outputs, 7 PWM outputs and 12 analogue inputs. It has an R3 shield layout, a new and standard layout which will be shared within the Arduino family making it easier for accessory makers to create Arduino shields for all devices. It has 32 KB of flash memory, of which 4 KB are required by the boot loader. It has a mere 2.5 KB of RAM. Programming it requires the Arduino 1.0.1 IDE. A short introduction to the quirks of programming the Leonardo can be found in the 'Guide to the Arduino Leonardo'.