FT232BM/BL USB to Serial RS232/UART TTL/RS485 FTDI DB9 Converter Adapter Module
The design uses Future Technology Devices Intl Ltd's (FTDI)FT232BM/BL chip. 1PCS DB9 Converter Adapter FT232BM/BL USB to Serial RS232/UART TTL/RS485 FTDI Module. The FTDI website provides the USB drivers for a virtual com port.