The LeoStick is designed to be functionally similar to the upcoming Arduino Leonardo, but given the "honey, I shrunk the kids" treatment!
Just pop it into your USB port (no cable required!) and upload straight from the Arduino IDE. Freetronics even included on-board RGB LED lights and a speaker in this handy sized board. All the usual Arduino pins are present and each LeoStick comes with low profile header sockets for plugging in modules, shields and wires.
Features of the LeoStick include:
Native USB port built-in, no need for any USB or FTDI cables
Two Full Color RGB LEDs on-board! Drive different colored outputs and fun feedback from your sketch right away. One RGB LED is completely programmable, the other does Power, USB RX and TX indication, the RX and TX LEDs can also be controlled.
On-board Piezo speaker element, play sounds, tunes and beeps. Can also be used as a knock/vibration sensor
Same I/O pins. The LeoStick provides all the same header connections as larger boards, you can connect all the same sensors, actuators, and other inputs and outputs as typical Arduino models.
Breadboard compatible, has 0.1" pitch pads and header pins can be fitted underneath
500mA polyfuse and protection on the USB port
ATmega32U4 microcontroller, Arduino compatible with on-board USB, 32K Flash, 2.5K RAM, 1K EEPROM at 16MHz
ISP 6-pin connector for advanced programming of the ATmega32U4 MCU
Getting to know your LeoStick
Freetronics have an active community forum here for fun LeoStick programs, installation and setup tips.
Their usual Getting Started guide page is here, including the first setup of the Arduino 1.0 IDE for beta Leonardo support.
Please note: The LeoStick currently uses a modified beta version of the upcoming Arduino Leonardo bootloader. There are some known issues with Windows 7 64-bit drivers and some library functions don't work perfectly yet.
Any firmware or Arduino Leonardo compatible support should not be considered to be final release firmware or in any way an official Arduino. Don't hassle the Arduino team with support or requests related to this board: they're solely Freetronics responsibility.
The LeoStick is also a very complete ATmega32U4 breakout and USB board by itself and the LeoStick can be programmed directly from the supplied standard ISP header by AVR Studio, Mac OSX-AVR, avrdude, WinAVR etc.