The USB to TTL Serial cable allows direct interface between the microcontroller TTL output andUSB port on PC. It provides an easy way to connect to your microcontroller/Raspberry Pi/WiFi router serial console port. Inside the 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 Beagle Bone Black. The driver allows the USB device to appear as a standard serial port to all windows programs, which can access the serial device exactly as if itwere a built-in serial port