Need some help with an accelerometer

Discussion in 'The Projects Forum' started by simf14, Apr 26, 2011.

  1. simf14

    Thread Starter Active Member

    Jul 27, 2007
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    0
    Hello and thank you.
    I have an analog output accelerometer board from ST micro (511-STEVAL-MKI014V1) that I would like to trigger an adjustable momentary audio alarm if the output reaches a desired level. Could anyone offer suggestions to a person with little electronic experience?
     
  2. rfordh

    New Member

    Oct 26, 2010
    6
    3
    I think the most important question is what kind of alarm did you have in mind? There are buzzers that will beep if you put a current through it, which you could probably drive with the output of a comparator. The comparator could have an adjustable threshold.

    If you want to have a more complicated alarm, it will probably take a more complicated circuit to drive it.
     
  3. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
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    Agreed. If you have only a speaker, or piezo, you will need to trigger a frequency generator. A simple 555 circuit will handle this task.

    If the alarm speaker is "bigger" than a hobby-sized speaker, you will also require amplification.
     
  4. simf14

    Thread Starter Active Member

    Jul 27, 2007
    43
    0

    Thank you that is exactly what I want a small piezo with 555. Can you send me any links to what you might have in mind? Again many thanks!
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
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  6. simf14

    Thread Starter Active Member

    Jul 27, 2007
    43
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    Thank you retched...any suggestions on how I control the trigger level from the accelerometer, in other words how do I enable that piezo circuit to buzz at 4g's or 2.5 g's? I believe earlier there was some talk of a comparator...
     
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