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Door Monitor

Discussion in 'General Electronics Discussion' started by stephan2307, Nov 17, 2014.

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  1. stephan2307

    stephan2307

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    Nov 17, 2014
    Hi,

    I was challenged to do a little project at work and I am a little stuck and was wondering if anyone could help me with this.

    Scenario: There is a door that we would like to monitor to see if the door is locked or unlocked and we would like to monitor this from a computer. Problem here is that we can't run a cable from the door to our office and there is no power available either. Door to office is about 15 meters with 2 walls between the computer and where the sensor needs to be fitted.

    So I had the following idea.

    Use a Raspberry Pi as a Server (php,mysql) on the local network. The sensor could be some sort of bluetooth device that sends out a signal when the door gets locked and again when it is unlocked. This bluetooth device could talk to a bluetooth router which could then talk to the raspberry pi.

    Problem I have is I don't know what sort of bluetooth device I could use for this ( it should be as small as possible ) and how to configure the bluetooth router to talk only with the raspberry pi.

    I saw the McModule project on Kickstarter and thought that that device was exactly what I needed but it seems that the website is under construction and you can't buy it anywhere.

    Can anyone help me with this or point me into the right direction? Also if there is another solution I am more than happy to listen to other suggestions.

    Thanks for your time and help.
     
  2. Colin Mitchell

    Colin Mitchell

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    Aug 31, 2014
    This requirement is more involved than you think.
     
  3. stephan2307

    stephan2307

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    Nov 17, 2014
    Thanks Colin, can you explain a little bit more in detail?
     
  4. Colin Mitchell

    Colin Mitchell

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    Aug 31, 2014
    How are you going to detect is the door is locked or unlocked?
     
  5. stephan2307

    stephan2307

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    Nov 17, 2014
    Because of the type of lock I can use a simple micro switch like one of these[​IMG]
     
  6. Colin Mitchell

    Colin Mitchell

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    Aug 31, 2014
    Use the change-over of the micro sw to generate a pulse for buttons A and B of a 303MHz Tx Rx
     
  7. stephan2307

    stephan2307

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    Nov 17, 2014
    Thanks for the suggestion but how would I hook that up to a computer so we can monitor what the status of the door is? would you just hook it up to the ports on the pi?

    Doh just realised that I forgot to mention that we want to keep a log of when the door has been locked and when it was unlocked ideally via a mysql db.
     
  8. Colin Mitchell

    Colin Mitchell

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    Aug 31, 2014
    The receiver has 4 outputs. You will use 2 of these. You will have to make a PIC interface circuit that plugs into the USB socket and delivers the lock/unlock data to the log folder.
     
  9. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    As your in the UK I would use easy radio. I have used these before and they work well. You will need to supply battery power obviously to the door sensor circuit. But this could be just a small micro which controls the UART comms and then goes to sleep to conserve battery power.

    http://www.lprs.co.uk/easy-radio/

    Just an idea. Also I know the technical director (designer) so if we had any issues I am sure I can get David to help

    Cheers
    Adam
     
    stephan2307 likes this.
  10. Colin Mitchell

    Colin Mitchell

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    Aug 31, 2014
    "As you're in the UK I would use easy radio."
    It is going to much easier to use 303MHz Tx/ Rx. It is only $4.00 and has everything finished and ready to interface. With 303Mhz the TX only takes 10mA for 300mS.
     
    stephan2307 likes this.
  11. stephan2307

    stephan2307

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    Nov 17, 2014
    Hey Colin could you send me a link where I can have a look at the 303MHz Tx/ Rx you are talking about?

    Thanks,
     
  12. stephan2307

    stephan2307

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    Nov 17, 2014
    I like this idea too but it seems a bit too big for what I need. Will have another closer look later. Thanks for the suggestion
     
  13. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    Oh sorry I thought he was in the UK. The last time I looked 303 MHZ in the UK was fixed mobile not ISM.
    Adam
     
  14. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
  15. stephan2307

    stephan2307

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    Nov 17, 2014
  16. Arouse1973

    Arouse1973 Adam

    5,164
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    Dec 18, 2013
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