Find and buy USB to Serial protocol converter IC. USB to UART Bridge IC converts USB data in to old school Serial protocol data which is easy to handle and program also. This creates a Virtual Com Port (VCP). FT232RL, PL2303HX, CH340 and CP2102 are popular USB to serial IC, each one has own advantages and some disadvantages, it may be in price factor or software Driver support or easy to solder chip. You should Chose your chip as per your requirement.