security system using remote to arm

Discussion in 'Embedded Systems and Microcontrollers' started by lihle, Mar 5, 2010.

  1. lihle

    Thread Starter Active Member

    Apr 12, 2009
    83
    3
    hi guys i am trying to finish my security system project. i would like to arm and disarm the system with a remote contol with two button(On and Off).my problem is how can i make the microcontroller able to recognise only one remote(i.e the one i use). i am currently using the PIC16f877.

    Thanks in advance
     
  2. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234
    what remote are you using???
     
  3. lihle

    Thread Starter Active Member

    Apr 12, 2009
    83
    3
    BMorse

    i am using a remote that was used for a fan . it has got two button on and off with a white IR led in it
     
  4. Markd77

    Senior Member

    Sep 7, 2009
    2,803
    594
    Not exactly the most secure system in the world as anyone with the same fan remote could use it or someone could record the transmission and play it back later.
    If you have access to an digital oscilloscope you could hook up a ir detector to find the codes transmitted by the remote.
    You will probably need an IR receiver module eg TSOP4838 in the finished project.
     
  5. lihle

    Thread Starter Active Member

    Apr 12, 2009
    83
    3
    Markd77

    i would like to ask if i use the remote in the following way will it work.i send the signal to a receiver which is inturn connected to PLL which capture only a certain frequency of which will be from the remote this time then to the microcontroller.

    help me out
     
  6. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234
    Using the remote from the fan does not give you any type of security, anyone with the same remote can enable / disable your alarm......

    You need to use a 38Khz modulated IR transmitter with a 38Khz IR Receiver module like this one: http://www.radioshack.com/product/index.jsp?productId=2049727


    and use an IR LED like this one >> http://www.radioshack.com/product/index.jsp?productId=2062565&clickid=prod_cs


    go here to learn more about this >> http://www.epanorama.net/links/irremote.html

    B. Morse
     
  7. lihle

    Thread Starter Active Member

    Apr 12, 2009
    83
    3
    B Morse

    Thanks i will try to read the staff.

    Lihle
     
  8. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    Microchip make some secure remote control chips, which are resistant to cloning etc.

    Have a look on their web site.
     
  9. lihle

    Thread Starter Active Member

    Apr 12, 2009
    83
    3
    rjenkins
    i can be glad if you can just refer to specific sites

    lihle
     
  10. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
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