This is a simple to use USB evaluation board for the GE865-Quad cellular module. All pins of the GE865 are broken out, so you'll have access to the state-of-the-art DAC, ADCs and GPIOs. No messy 3.8V regulation. No tricky 3.3V to USB converter. It's all done for you! The serial pins are wired up to an FT232RL UART-to-USB bridge. You can plug the GE865 Evaluation Board into any USB port on your computer and it will act just like a standard COM port. Power up the board, turn on the module, and you can start sending and receiving AT commands via a terminal emulator. The USB chip can be disconnected (by clearing all solder jumpers) to allow for external control of the TX and RX pins on the GE865 module (3.0VDC max!). Power can be provided through either USB or an external power source, via the barrel jack connector or Vin/GND pins (5-9VDC). To turn the module on, hold the ON/OFF button down for 1-2 seconds - just like turning on a cell phone. Note: Some USB ports cannot source enough current to power the GE865 module. If the power supply is inadequate, the module may shut down while attempting to connect to the cellular network. An external power supply will correct this problem if it is experienced. The board comes fully assembled with the GE865 module, 3.8V power regulation circuitry, SIM card socket, U.FL antenna connector, and other supporting circuitry. All pins of the GE865 are brought out to two 0.1" headers. 3.8V is regulated through a surface mount SPX29302 LDO regulator. Project description, more information and ordering can be found at https://www.sparkfun.com/products/9342 Telit GE865 documentation: http://www.telit.com/en/products/gsm-gprs.php?p_ac=show&p=47 FTDI USB Drivers: http://www.ftdichip.com/FTDrivers.htm