This is the 2.4 GHz Chibi wireless development board v1.1 that integrates an Atmel ATMega32U4 AVR microcontroller (32 kB flash, 2 kB RAM) with an Atmel AT86RF230 2.4 GHz 802.15.4 radio. This board is part of the FreakLabs Chibi series and is designed as a low-cost starter board for people new to wireless sensor networks or working on smaller wireless applications that don't need a heavy protocol stack. It's also a great learning platform for both microcontroller programming and wireless communications.
The board comes default with an external antenna connector. There is also an option to have both external antenna connector and surface mount antennas populated. If both antenna options are installed, you'll need to specify which antenna will be used by default. This can be chosen in the dropdown box below.
The board is designed with remote applications in mind. It comes with a AA battery case and circuitry that can accomodate both rechargeable and alkaline batteries while maintaining a constant 3.3V output voltage as the batteries drain. This is especially important for sensors that require a stable power supply.
For more adventurous people, the battery holder can be removed and a solar cell and/or supercapacitor can be placed in the terminals. The boost converter will take the output and use it to power the MCU as well.
The board also features a FreakLabs universal serial connector (USC) so that it will be compatible with any of the FreakLabs peripheral boards.
The chibi wireless software stack and FreakUSB USB stack is available as open source software and can be downloaded from the FreakLabs website.
FL-CHIBI-DEV v1.1 User Guide
Link: Firmware Downloading on AVR USB Microcontrollers