Decoding 433.92mhz transmission and replicating

Discussion in 'Wireless & RF Design' started by bigclick_dean, Jul 18, 2010.

  1. bigclick_dean

    Thread Starter Member

    Jan 24, 2010
    38
    0
    Hello,

    I am trying to capture, decode and then replicate the Rf messages coming from a little remote controlled powerboard/powerstrip (http://www.jaycar.com.au/productView.asp?ID=MS6150).

    So far I have been able to capture the messages using a scope (using my PC soundcard) and I have worked the messages out to be the following.

    Button 1
    0000000010101001011011100010111100

    Button 2
    0000000010101001011011000010110000

    Button 3
    0000000010101001011000100010010000

    Button 4
    0000000010101001011010100010100000

    Button 5
    0000000010101001011001100010000000


    Each of these messages are sent after a long pulse is sent by the remote (about 2-3 times the length of a regular bit).

    I am also unsure if I should be inverting these bits.

    I am trying to figure out what they mean (they all appear to start with the same first 16 nibbles so I am guessing that would be the unique code for the remote) and then the next bits may be a button code and checksum.

    I do however have another remote, made by the same company and I captured its messages too.

    Button 1
    0011001101100100000011100011100110

    Button 2
    0011001101100100000011000011101110

    Button 3
    0011001101100100000000100011001110

    Button 4
    0011001101100100000010100011110110

    Button 5
    0011001101100100000001100011010110

    There doesn't seem to be anything similar between them so I am getting the impression that the whole message is unique per button, but this doesn't really make sense as I though each remote would have a code and then each button would have the same command code per remote.

    They could be encoded somehow but I would have no idea where to start.

    What I am trying to do is to be able to use an arduino (or other controller) to send out these messages without having to capture the code of each remote everytime. So if I wanted to add another board I would just tell the arduino to generate a new remote code and off I go.

    If anyone can help me figure out how to decode the messages to have a unique remote code and then the individual button codes (which I imagine would be the same across each remote) then it would be much appreciated.

    Cheers,
    Dean
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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  3. bigclick_dean

    Thread Starter Member

    Jan 24, 2010
    38
    0
    Hi Beenthere,

    I have had a look at the remote signals a fair few times and they always remain the same, they also remain the same when pairing the remote with different powerboards or unpairing and then repairing so I think it is just a simple fixed code. Also the remote is transmit only and the board is receive only so the communication is only 1 way.

    It is possible to pair multiple remotes with the one powerboard as well so I have a feeling that each remote has a unique identifier and then each button has a set code that is the same across all remotes. When you pair the remote with the powerboard it must store the unique remote code in its memory and then when it receives a message from that remote it is able to decode it.

    The powerboard (reciever end) is run off a PIC microchip so I don't know if it would be possible to read the code back from the chip and see how it is decoded. I have a feeling that the chip is probably protected though.

    Cheers,
    Dean

    Cheers,
    Dean
     
  4. bigclick_dean

    Thread Starter Member

    Jan 24, 2010
    38
    0
    Anyone? Is there another forum that would be better to ask a RF question?

    Cheers,
    Dean
     
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