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BS2 Voltage Sensor — Parallax Forums

BS2 Voltage Sensor

everesteverest Posts: 141
edited 2009-03-08 16:34 in BASIC Stamp
I'm looking to build a more accurate voltage sensor for my Observatory Control System. Currently I simply light up an LED and measure the brightness with a Light to Frequency converter chip. . .silly, but it's fairly accurate to within .2 of a volt. That said, I want something more accurate. . .I've seen some analog to digital converters that might do the trick, but I haven't the slightest idea how I would wire one up. . .anyone have a guide? Again I've searched like crazy in the forums, but the search features seem fairly limited. Any help from the gurus is appreciated as always!

-Jeff

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2009-03-08 14:34
    · http://search.parallax.com
  • Mike GreenMike Green Posts: 23,101
    edited 2009-03-08 14:45
    Download the tutorial "Basic Analog and Digital".

    Pretty much all the tutorials are in the Stamps in Class Downloads area.

    Go to the main Parallax webpage and select the Resources tab. You'll see a list. Pick Downloads, then the next list will have Stamps in Class Downloads.
  • everesteverest Posts: 141
    edited 2009-03-08 15:48
    Has anyone used one of these?

    http://www.trossenrobotics.com/phidgets-precision-voltage-sensor.aspx

    Seems like a nicely packaged solution. . .I'm searching again now and see the photocell solution (I never thought of that!). I initially tried to use a photo resistor, but I got pretty widely different readings from day to day for reasons I can't explain. I'll look for A/D solutions next. Thanks!

    -Jeff
  • everesteverest Posts: 141
    edited 2009-03-08 16:34
    Oh, and Mike, thanks for the reference to that project. . .I was looking in the wrong places, and that's an excellent discussion on how to do what I need. I still have a few specific questions on the schematic though. . .for example, I need to monitor a 12v battery bank, that will be a common ground for the both the STAMP circuit and the ADC chip. I'm guessing I just need to use resistors to drop the 12v voltage into the 0-5v range and hook that to the Vin+ and Vin- on Page 44. . .is that right? I've already managed to explode one pin on my Stamp with a wiring mistake (which can almost put out an eye if you aren't careful!!). Let me know if I'm on the right track if you can. Thanks!

    -Jeff
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