:) Still interested. How many boards are you doing? Also, thoughts of a 7971 driver board? =:D Michail
In a message dated 2/27/2015 8:17:05 P.M. Pacific Standard Time, neonixie-l@googlegroups.com writes: You guys persuaded me to add a 2nd LED under each tube. Done. 3 - not going to happen. 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. 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. Getting close to ordering boards,,,,, if I can just put a stop to the creeping elegance. Terry On Wednesday, February 25, 2015 at 8:34:26 PM UTC-6, Terry S wrote: Ok, John shamed me into tweaking the layout. Here's the latest revs. I did address the lines crossing the hole keepouts, as well as rationalizing out a whole bunch of vias. My criteria for a clean design includes as few as possible jogs in the traces, minimal number of vias within reason, and an adherence to x on one layer and y on the other.... until the routing is done, then around the margins, it becomes OK to violate that rule. Symmetrical layouts of repeated circuitry. Also only 45 degree bends, (90 or 45 at vias OK) clean pad entry, (no acid traps), trace widths no narrower than the design justifies... very conservative rules. Makes for high yields and reliable boards. Anyway, now I'm pretty happy with both of these boards, and after some careful design validation, I'll be ready to order boards. So your feedback, please. Thanks, Terry (https://lh3.googleusercontent.com/-CN1uD7heTcc/VO6FCAJkq0I/AAAAAAAAADg/4EdQtsuu8bA/s1600/main.JPG) (https://lh3.googleusercontent.com/-pSKnky0S_lk/VO6FL0FteYI/AAAAAAAAADo/Xt71tF6X8jQ/s1600/extension.JPG) -- 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 _neonixie-l+unsubscribe@googlegroups.com_ (mailto:neonixie-l+unsubscr...@googlegroups.com) . To post to this group, send email to _neonixie-l@googlegroups.com_ (mailto:neonixie-l@googlegroups.com) . To view this discussion on the web, visit _https://groups.google.com/d/msgid/neonixie-l/deb17d20-5ec4-49c5-a8b4-8f3e8ff9e17e%40googlegroups.com_ (https://groups.google.com/d/msgid/neonixie-l/deb17d20-5ec4-49c5-a8b4-8f3e8ff9e17e @googlegroups.com?utm_medium=email&utm_source=footer) . For more options, visit https://groups.google.com/d/optout. -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/39243.1aa72536.4223ac02%40aol.com. For more options, visit https://groups.google.com/d/optout.
