Description:
This is an easy USB to serial TTL cable that works fine with the Rapberry Pi and other micro-controller boards. This cable comes with a PL2303HX chipset and a black USB body and is compatible with Windows XP/Vista/7 and Max OS X (not Win8 compatible).

The cable is easiest way ever to connect to your microcontroller/Raspberry Pi/WiFi router serial console port. Inside the big USB plug is a USB<->Serial conversion chip and at the end of the 36" cable are four wire - red power, black ground, white RX into USB port, and green TX out of the USB port. The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets.

Because of the separated pin plugs, this cable is ideal for powering and connecting up to the debug/login console on the Raspberry Pi or BeagleBone Black. Connect the pins as shown to power the Pi or BBB and establish the RX/TX link.

Specifications:

• USB A connector (to PC / Mac)
• Output: Four wires with red; power, black; ground, white; RX into USB port, and green; TX out of the USB port
• Power pin: 5V @ 500mA direct from the USB port
• RX/TX pins: 3.3V level, for interfacing with the most common 3.3V logic level chipsets USB converter chipset: PL2303HX

Resources:
Driver download page
PL2303HX Chipset datasheet