Does a 1/4 mile timing application exist?

Discussion in 'Mac Apps and Mac App Store' started by morrisman1, Sep 4, 2009.

  1. morrisman1 macrumors 6502

    #1
    Ok i have a macbook, it has a three axis accelerometer in it to sense when it is dropped (turns off harddrive) but its not restricted to using that. there is an application for iphone and ipod touch that uses the accelerometers in those to estimate 0-100 and 1/4 mile etc, just like the g-tech unit. Has anyone heard of an application that can use the macbook's accelerometer in the same way?

    thanks
     
  2. gr8tfly macrumors 603

    gr8tfly

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  3. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
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    NYC
    #3
    You can't measure distance with an accelerometer. It only measures acceleration.

    Unless we're not talking about the same thing.
     
  4. gr8tfly macrumors 603

    gr8tfly

    Joined:
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    #4
    The iPhone apps just look for a change in acceleration [after 1/4 mile], assuming you let off or start braking after the timed distance. Not too accurate a method, though. Otherwise, someone just has to hit the stop button. Still it could be off by a couple hundred ms.
     
  5. morrisman1 thread starter macrumors 6502

    #5
    i presume you have forgotten calculus. Integrate the acceleration curve and you get the velocity curve, integrate that and you get distance. The app has the simple job of taking acceleration and drawing the two other graphs and having flags for when d=400m give the time and velocity*. The accelerometers in the macbooks are pretty good, with a well written program id expect the accuracy to be about ±0.3s

    Dynolicious on the iphone does this but i dont have one of them :(
     

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