Some sort of logic level converter like this should work: https://www.sparkfun.com/products/12009
On Wed, Dec 30, 2015 at 4:54 PM, Andy Tefft <[email protected]> wrote: > Anyone been using a Raspberry pi in any nixie projects? > > Many years ago I worked on a clock that basically used a frequency counter > as a display. Basically it output 1 pps and the counter just counted them > to mark off the seconds (with some smarts to handle the rollovers from 50 > to 0 seconds and so on). This used an AVR microcontroller, with a bunch of > external components - a switch and rotary encoder for setting the time, > some power supply related stuff and so on. There would have been additional > external components needed to support more stuff I wanted to add, like a > battery backed RTC. > > While I had it working nicely on the breadboard, I never quite got it > right on my protoboard version and soon ran out of free time to work on > it. This year my son wanted a raspberry pi for Christmas and I ended up > getting myself one too - figuring I could revisit the counter clock. > > All in all the hardware itself is about what I paid in total for the parts > I'd used before, and it seems like nearly everything I need is in the pi > itself (yes, it is way overkill for a clock of this nature!). I'm thinking > I will even connect the pi to my wifi and use ntp as the time source which > does away with all the hardware and software needed to set the time. > Theoretically I just need a power supply (my counter has +5V available > since it's all TTL, though I'm not sure I would use it directly), a > connection to the counter's input, and a connection to the counter's reset > signal. > > Initial quick tests are good with one exception - I had just connected an > AVR output to one of the pins on the reset button on the counter and the > AVR was able to toggle that output and reset the counter (pretty sure I was > powering the AVR with 5V). This same trick does not work with the pi, > presumably due to its puny little 3.3v-level outputs. Anyone have a > standard, simple go-to for interfacing between old TTL circuitry and a pi > or something like it? > > -- > 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 email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/CAM1F4kQZpJn25%2BER8f5o4jncRd51kLd9J9BXkfyz-LKjF5worA%40mail.gmail.com > <https://groups.google.com/d/msgid/neonixie-l/CAM1F4kQZpJn25%2BER8f5o4jncRd51kLd9J9BXkfyz-LKjF5worA%40mail.gmail.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 [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/CAJrqPH-dS%3D4aiH_CM%2Bi3xpX925F7wR%3DY_K5DMHPEpSp0gAVY1g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
