I did ask for comments -- and I appreciate the feedback and all the helpful suggestions.
Regarding the connector spacing -- I still need to verify that. The parts come from the Eagle library. From a quick look just now at the part drawings, they look reasonably accurate. I need the board edges to touch to get the tube and colon spacing right, although even if they don't the colon can be adjusted somewhat. I've used similar headers before and they typically mate fully. The new ID circuit only required one additional pin -- the 5 volts for the pull-up was already on the extension board. So I still have one open pin.... Terry On Sunday, March 1, 2015 at 2:43:47 PM UTC-6, jrehwin wrote: > > I also liked Pete's cascode anode driver idea so much I've adopted that > as well. > > > > Interesting side effect of doing that -- no need for a ground connection > to the 2 digit extension boards. That seems strange even to me... but the > nixies don't need it, the cathode drivers are all on the main board, and > the LED and colon drivers don't require a ground connection either, as they > are low side drivers on the main board. > > My digit boards ended up the same way. No ground, no ground plane. Just > anodes and cathodes. > > I peered at the engineering drawings of various right-angle male and > female headers to see if I could figure out what their mated width was, so > I could put the holes in the right place for > my boards to plug together neatly. I finally gave up, ordered a few from > various vendors, assembled them, and measured the result. Headers are > cheap, having boards made is ... less cheap. > > How did you come up with the spacing for yours? The silkscreens look > really nice. > > > This frees up two pins on the 20 pin inter-board connectors. Hmmm.... > Thinking out loud, I'm wondering if I can use one of the pins to identify > to the Arduino just how many extension boards there are -- therefore > allowing the software to auto-configure based on the hardware. A pull-up on > the extension board and a pull-down on the main board would form a voltage > divider I could feed into an analog input. 2 extension boards would change > the voltage level. The code can then make the mux rate and colons behave as > required, based on the number of tubes present. > > Slick! I guess you'd use one pin to power the pull-up, and the other pin > for the sense lead? > > > Getting close to ordering boards,,,,, if I can just put a stop to the > creeping elegance. > > Believe me, I know the feeling! I just tweaked my silkscreens to make pin > 1 clearer and show the transformer on the Tayloredge board to make the > orientation clear, added a voltage source jumper, rerouted the power to > avoid some weird crossovers, and moved a few parts to make the trace runs > nicer. It's so tempting to order a set, the renders on the board house > site look really nice to me. > > - John > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/cea0cc10-7dd2-4aca-a9d4-22fea4553d9f%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
