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Electronics simple A/D conversion?

Discussion in 'Modding' started by OtakuHawk, 17 Jun 2006.

  1. OtakuHawk

    OtakuHawk What's a Dremel?

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    I'm looking for a dirt simple 12-bit Analog-to-digital conversion solution.

    I'm ordering some LM35 temperature sensors, and I want to be able to display the temperature on some nixie display tubes I bought earlier.

    I've got space for 3 tubes on the 5.25 drive space (got some switches I'm cramming in there too)

    so I need 12 bit resolution, parallel output.

    the LM35s put out 10 millivolts per degree C, so the range of voltage needs to be 0-5.

    I've seen the PIC microcontrollers have build in A/D and a few PWM channels, but does anyone know anything simpler?
     
  2. DougEdey

    DougEdey I pwn all your storage

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    You could try using dividers, so when it hits a different level you get a different digital output.
     
  3. ChromeX

    ChromeX Minimodder

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    You mean have a stack of resistors, and set them up in a massive potential divider circuit? It works thats for sure, i've built one. otakul, why not feed the analogue outputs into an op-amp setup as a summing amplifier? That would give the a/d conversion and probably feed you with enough power to soruce a nixie tube.
     
  4. DougEdey

    DougEdey I pwn all your storage

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    hey, the man said simple, don't get much more simple then a stack of resistors ;)
     
  5. ConKbot of Doom

    ConKbot of Doom Minimodder

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    simple or cheap? I would see if you could get ahold of parallel output DAC, should make things pretty easy to do if you can find one. check out maxim or ti to see if they have any.
     
  6. g0th

    g0th What's a Dremel?

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    You'll need a handful of logic to drive the Nixie drivers to display the temperature anyway, so it's probably worth just using a microcontroller.
     
  7. agent420

    agent420 What's a Dremel?

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    That's what I was thinking as well. And if you go that route, it's probably less complicated to use a 2 wire interface sensor like the LM92 or similar than it would be to go through an AD conversion process. It would also relax any precision analog supply and design requirements you might run into contending with the management and processing of such a small signal in a noisey environment, not to mention eliminating a dozen or more interconnections and board traces.

    So I guess my definition of 'simple' is to skip it all together :D
     
    Last edited: 19 Jun 2006

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