TL;DR Can't find unknown RS485 baud rate
I need some help.
I have a lighting controller (brain) that controls some dimmer modules. The circuit board for the brain is labeled RS485 between the brain and the dimmers. I want to replace the brain with my arduino.
The first thing I need to do is "hack" the protocol that it uses so that I can duplicate it with the arduino.
I connected up my FT232 USB to Serial converter set to 5v after finding the ground and send pins with my multimeter and tried every baud rate I could find published online as a typical baud.
For baud of 57600, 76800? and 115200 I got random characters (question marks, question marks in black diamonds... Etc) for everything else I got nothing.
What could I try to find the baud rate and format that I could duplicate? If it were hex or some other form would that effect how the serial terminal reads it? Would an incorrect voltage effect the ability to read?
It's a proprietary device so I wouldn't be surprise if it weren't a standard baud rate but could it be anything? What are the limitations? Does it have to be an exponent of 2?
I'm just thinking out loud here, a point in the right direction would be greatly appreciated.