This type of adapter will work when we want to establish serial communication between a microcontroller device (using logic level signals of 3.3 or 5.0 volts) and a PC with an RS232 port. Adapter contains FTDI chip inside!

This adapter gets its power from the microcontroller side, which generally uses a power supply of either 3.3 or 5.0 Volts. It converts the logic signals into those that are compatible with the RS232 protocol. This type of adapter can be totally enclosed within the DB9 female connector that is used to mate with the PC’s RS232 port.