Are you using the TLC5940 like it says in the title? I've been looking at those as drivers as well... They seem a pretty good choice for what I have in mind (direct drive controlled by a Wemos). I'd also be interested in your experience of what the PWM is like.
I always like to do progressive dimming and having a driver that takes care of that really makes the code a lot more manageable. I'd also want to do "filament pre-heating" which basically turns the segments on gently, and the PWM on the TLC5940 appears to be per segment! Yaay!
Yes that's the chip I've been using. Let's team up on this. I've seen how some others in the community did these numitrons before but they don't have any PCB or anything anymore... I asked even. We've got newer chips and stuff now that we can use! Let's make some cool new stuff and sport it!
Yeah that woud be great: My aim would be to make a commercial product out of it, but if you're happy to allow me to do that on whatever we come up with, I think that would be great. Of course, it would go the other way as well: if you had any interest to sell it, that's fine by me...