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Stamp Works experiment #28: Reading voltage with the MC14489. Has anyone done this? — Parallax Forums

Stamp Works experiment #28: Reading voltage with the MC14489. Has anyone done this?

MartythedMartythed Posts: 8
edited 2013-05-31 12:45 in BASIC Stamp
Hello to all.

I’ve been plowing through the Stamp Works experiments using the Basic Stamp 2 (BS2-IC) and I’m especially interested in Experiment 31 using the MC14489 seven segment LED multiplexer.

At the end of the experiment there is a challenge to go back and do Experiment 28 (reading voltages) using the MC14489 and 0831 ADC with seven segment LEDs for the voltage readout instead of the DEBUG function.

Has anyone done the code for this challenge experiment?

Thanks for any help.

Marty

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2013-05-31 11:15
    No, but I've done all sorts of similar things. The whole idea of a challenge is for you to do it and learn from the experience. Make sure you've done the experiments where you read a voltage using ADC. Make sure you've gotten the LED to display a number. It's then a pretty simple step to do the reading of a voltage, store it in a memory location, then display it on the LED. Look at some of the examples in the Nuts & Volts Columns. There's very little difference between displaying a number from some other source and displaying a number from an ADC. Similarly, there's very little difference between reading a voltage and displaying it on a PC using DEBUG and displaying the same number on some other display device (like an LED display).
  • MartythedMartythed Posts: 8
    edited 2013-05-31 12:45
    Thanks for the quick reply, Mike.

    I have several articles by Scott Edwards and Jon Williams from N&V which I'm going through, and I've done the experiment in Stamp Works using the MC14489; now it's just a matter of substituting the MC14489/LED combination for the DEBUG function in the voltmeter experiment.

    The project I'm working on is a temperature alarm/readout using the LM34/ADC0831 combination with four adjustable alarm points with relay outputs. I have everything working on a bread board using discrete LEDs for the temperature readout at 10 degree F intervals but now I think that a 7-segment LED readout would be much better.

    I guess it's just a matter of working on it until I get it right.

    Thanks again,
    Marty
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