We have a unit that does an RS485 handshake with another unit. it's very basic and only has to control 6 LED's and instruct the unit that it is connected. We need to understand the RS485 data and create a raspberry pi interface so the the unit handshakes with the raspberry pi and not the other unit. We have test equipment so we can provide you with information as you need it. Once we know what the code is and how to communicate with it, we can build our own PCB that will input to a raspberry pi GPIO rather than LED's. There are 3 further projects once this one is complete. We're keen to find the correct developer for all the elements in the project.