USB-RS485 is USB to RS485 converter and can be used with any computer with USB including OLinuXino.
A20-OLinuXino-MICRO, A64-OLinuXino, A13-OLinuXino, A33-OLinuXino, iMX233-OLinuXino have Audio input, for these boards we got very compact and flexible PC-MIC-3.5MM
For these who deal with tiny SMT parts we got stackable X*Y smt SMT-BOX-25x32x22 with spring loaded cap:
SLD-SPONGE is soldering tip cleaning sponge:
SLD-STAND is metal stand for soldering irons with place for soldering sponge:
CONNECTOR-GX16-4 is robust connector for panel mounting and can connect up to 220V/20A:
WIRE-CLIP-300F is female connector at one end which easy connects to boards with headers and sprint loaded contact at the other end. If you make signal analyzer with FPGA boards these clip wire connectors are very handy to attach to existing boards:
ALUMINUM-HEATSINK-TO-220 is low cost heatsink for TO-220 devices like voltage regulators and transistors:
olimex 
Mar 13, 2020 @ 10:26:49
Regarding the USB-RS485, my experience is that you need 3 wires for connecting two devices reliably on a RS485 bus, where the 3rd wire is GND. In the office, everything usually works just fine with 2 wires (A and B), but on site things are different. What is your feeling on this?
Mar 13, 2020 @ 10:55:47
RS485 requires just two wires to work, it’s differential current loop, the “third” wire usually is the shielding connected to ground but it’s not part of RS485 loop. Ethernet cables also works with twisted pairs current loop and although there is shielding connected to GND the Ethernet cables works as reliable with shielding and without shielding. The shielding is done to protect the twisted pair from lightenings on open air, which if strike the cable will burn all electronics (kV inducted potential). So to conclude it’s always better to have shielding, but if you use it indoor it is not necessary.