This cable is a USB to Serial (TTL level) converter cable. It’s identical functionally to the FTDI Cable. It’s one of the easiest ways to connect a TTL interface device to USB. and fits directly to many boards including the Lilypad mainboard. The cable uses FTDI’s FT232R chip, which is powerful and well documented. The device is housed inside the USB ‘A’ connector and is terminated at the end of a 1.8-meter cable (6 foot) with a 0.1″ pitch header socket which provided access to transmit (Tx), receive (Rx), RTS# and CTS#. These lines all operate at 3.3V levels. Also brought out in the header are VCC (5V) and GND.