Riva:
I should have jumped forward to your last message first instead of working my way through them one at a time and then going of reading about the connection example of the RS485 modules and then trying to decode the protocol only to find you have already done it. LOLGlad your getting consistent and predictable results now and look forward to you posting the project is finished and working as expected. Also glad to help though I don't feel I helped much apart from showing someone was listening.
I would like to investigate the old MAX485 modules in more detail as I feel the boards you bought are probably just the same as the rest of them that look the same (like mine) but maybe they have faulty MAX485 chips or some other issue.
Not going for the smoke blowing but even a little bit of assistance around where to look or advice about getting a logic analyser just meant that I moved that much faster. It probably stopped me from giving up altogether quite honestly.
I've been putting my code on github here: GitHub - Russ-K/vado-identity-shower-interface: Arduino program to interact with the Vado Identity IDE-147A-C/P / SENSORI Identity IDE-147C-C/P
It's not perfect but I'm definitely getting there. Needs a lot more refactoring and tidying up but I want to get it working with all the safety features and so on so and then refactor once it's working.
If you want to PM me your address I'll send you one of the rs 485 modules if you want to have a look. No pressure but definitely the least I can do. And I very much doubt I'll be using them. 