A simple converter can be sourced online, but the only thing he could find locally that was even close was a USB to RS-232 converter. He used that component to craft his own USB to RS-485 bridge.

[Jethomson] worked out a way to use a Nokia USB cable at a USB to Serial cable. He was able to pick up one of these cables for less than $3 delivered. A little probing worked out which conductors ...

This port powered device connects to any 2.0 USB Port through the supplied cable. The module provides an RS-232 output including DTR and a simultaneous RS-485 4 wire output. This module is protocol ...