USB-RS485-PCBA USB to RS485 Interface Board – USB-RS485-PCBA. These USB to RS-232 / RS-422 / RS-485 converters provide a fast and simple method to convert serial UART to USB. The USB connector contains a small circuit board featuring the FTDI FT232RQ (RS 730-0168) serial UART interface IC to handle all the USB signalling and protocols. There are two LEDs to indicate data being received and transmitted.