Well [robot's i.e. its microntroller's] communicating with the PC might be a very impotrant part of the game. The reason may be taking decisions based on DIP (digital image processing) that is being done only by the PC paralelly. For this we need to use the serial port on the PC
and the one on the microcontroller (i.e. the UART or the USART).
A major area of concern is that the modern PCs have no serial port at all. However they might be having a multitude of USB ports. But interfacing the USB port is a much...much more tedious task as compared to interfacing a serial port.
But when He has made problems, He has given solutions too. This is a right opportunity (need) to use a USB-to-Serial adaptor for your laptop/PC so that you get a dummy serial port on your laptop/PC which can be interfaced as as if a real serial port existed on yor laptop/PC.
For further information let us discuss.