The Arduino Fio is a microcontroller board based on the ATmega328P runs at 3.3V and 8 MHz. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 8 analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. It has connections for a Lithium Polymer battery and includes a charge circuit over USB. An XBee socket is available on the bottom of the board.
The Arduino Fio is intended for wireless applications. The user can upload sketches with an a FTDI cable or Sparkfun breakout board. Additionally, by using a modified USB-to-XBee adaptor such as XBee Explorer USB, the user can upload sketches wirelessly. The board comes without pre-mounted headers, allowing the use of various types of connectors or direct soldering of wires.