Flash sensing data logger

Discussion in 'Electronics & Electrics' started by wahid, Mar 21, 2017.

  1. wahid

    wahid Member

    Joined:
    Apr 22, 2002
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    Location:
    BF2 killed my Ti :(
    Hi, I would like to log the number of flashes, time of day, and day of week, from a permanent speed camera flash unit.

    There is a low conspicuity mounting spot available a few metres in front of the flash unit, on top of a public telephone enclosure. The flash is a flood type that lights up the entire intersection so there is plenty of light.

    I envisage a small data logger PCB, photo cell and coin battery in a water resistant box, capable of a one week deployment. The photo cell will have a small hood to give it some protection from the sun, lightning flashes, and sun glints off vehicle windows.

    Can anyone please recommend a suitable kit or ready made board that might suit please?

    Any advice appreciated.

    Thanks.
     
  2. _zak

    _zak Member

    Joined:
    Oct 12, 2009
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    310
    I'd be surprised if you found a ready-made board or kit for this application - it's pretty niche. However, it wouldn't be too hard to make up a prototype. Things you'd need:
    The first thing (and probably the trickiest part) is to work out what 'flash' you want the Arduino to record. This is changed by the little pot on the photodiode module, and is probably going to be hard because the camera might go off during the day or at night.

    After this it's pretty simple - when the photodiode sees the flash, it pulls D0 high and wakes the Arduino. After being woken up, the Arduino queries the RTC for the time and date, writes it to the SD card, then goes back to sleep.

    The code should be pretty simple, and if the Arduino's asleep most of the time, won't use too much power. It definitely wouldn't be able to be powered by a coin cell, but a small LiPo should be fine for a week or more I would think (though I'm not entirely certain about the power the photodiode module needs).
     
  3. RobRoySyd

    RobRoySyd Member

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    Jan 24, 2008
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    Sydney
    You'd be very unlikely to find anything off the shelf to do this. Fairly trivial task though to make something using say an Arduino that'd meet the spec.


    Only slightly tricky requirement is going to be getting the power consumption as low as possible as it's to run off a battery for quite some time.

    [edit] What he said ^^^^
     

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