This board converts a USB connection into a 5 volt Serial TX and RX that you can connect straight to the Arduino Mini, Arduino Ethernet or other microcontrollers, allowing them to talk to A PC.
One of the nice features of this board is a jumper on the back of the board that allows the board to be configured to either 3.3V or 5V (both power output and IO level). This board is shipped with 5V being the default, but you can cut the default trace and add a solder jumper if you need to switch to 3.3V.
