The board is designed to be flexible in the user's power source availability, allowing for an ATX power supply to power the board, or the user can choose to install the voltage regulator kit for use with any power supply 7V-30V.The board features a developer friendly expansion port supporting I2C, SPI, UART, as well as a few ADC pins. All 14 expansion pins can be used as GPIO as well.

Features:    
1.Supports multiple communication configurations
--2 thermistor connectors with circuitry
--2 N-MOSFETs for extruder/bed, or whatever
--Selectable 12v(or supply voltage)/5v endstop voltage
--Edge connectors enabling right-angle connections
--13 Extra pins available for expansion and development - 6 analog and 8 digital, with the following capabilities, and SD CARD SUPPORT

2. Supports multiple power configurations
-- Logic & Motors supplied by ATX power supply (needs molex harddrive connector, and optional 4pin atx connector for additional 12v/supply voltage)
-- Logic supplied by USB bus ,optional on-board voltage regulator (molex harddrive connector cannot be installed at the same time)
-- Motors supplied by 5mm screw terminal 7-35V  

3.Small design - board is 100mm x 50mm (4" x 2") - barely an inch longer than a business card!
4.Sanguino clone, Atmel's ATmega644P - ATmega1284 drop-in compatible!!
5.UART1 (RX and TX)
6. I2C (SDA and SCL)
7.SPI (MOSI, MISO, SCK)
8. PWM pin (1)
9.Analog I/O (5)