I was wondering if it would be possible to get hold of someone that started an discussion years back?
Most discussions never end in a well explained solution.
It would be really nice if project that get questioned in a forum, could have a link at the end to a tutorial of that finished project!
Anyway, most people are newbies that dissappear after they figured it out (with the help of every one els), without posting the answer.
So is there any way of making contact with such old arduino forum posters?
Go ahead and comment on the thread in question with a request for an update. The forum will warn you about replying to an old thread but you can ignore that because this is perfectly appropriate. If you don't get any reply there after several days, you can do some web sleuthing to find the person's GitHub, Instructables, hackaday.io, social media, etc. accounts, where you might find the finished project. If you find it, you can post a link to it on the forum thread so others can find it. If all else fails, send the person a private message.
Another option for the OP is to start his/her own Thread and just describe his/her problem from the start - perhaps including a link to the earlier Thread.