Many thanks again for the help on this. Somewhat improbably, I now have a working LED-based prototype on the breadboard - it includes the modes of the original and a few new ones too. I have multiplexed it for now - to save space and bits at least - I started out the hard way but then discovered the timer interrupt of the Arduino chip which makes it much easier. But my display is fairly well abstracted from the rest of the code so if it turns out I want to direct drive, it's not rocket science to change it.
So my circuit is fairly simple - In each multiplex cycle, the Arduino writes out to 3 74HC595 shift registers: * 1 controls the anodes of the 14 segment displays (just one at a time in this case) - these go through 2N3904 transistors, since the total draw of one character is more than the register can handle * The other two control the segments; for now I'm using resistors such that the 74HC595 can sink the current so they are connected directly to the cathodes. Now thinking about moving up to the tubes. Very simplistically, I'm seeing the eg B7971 as a bigger version of the common-anode LEDs I'm using - just requiring a higher voltage and current, so needing to be driven through appropriate transistors. I'm sure it can't be *that* simple though - can anyone broadly summarise what other things I need to consider? -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/iCfUhWC0mzgJ. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
