Introduction - If you have any usage issues, please Google them yourself
The serial (COM) port is one of the simplest ways to communicate between a PC and a
microcontroller circuit. Most microcontrollers have hardware serial ports and most
microcontroller compilers have built-in functions to read from and write to the hardware port.
Hardware serial ports with their 9-pin D connectors have disappeared from laptop and desktop
computers, but are easily produced with a low-cost USB-to-serial cable adaptor. For embedded
systems, a common approach is to add a FT232R USB-to-serial chip to the circuit so that the
hardware connects to the PC though USB. Another option is to add a USB-to-serial module, for
example the UM232R by FTDI or the USBMOD3 from DLP Design. These modules add glue
circuits and a USB connector to the converter chip for an easy-to-use self contained solution.