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I've bought that famous Receiver/Transmitter RWS-375 and TWS 375. I want to clone the remote control of my garage door.
So I connected the RWS-375 in my Arduino, and build a program to receive the sinal that the remote control send.

However every time I press the button the program writes differente sequence of characters. I mean, I never get the same sequence of characters from the remote control.

I've already tried changing the bits per seconds rate, but I think the correct is 9600, right?
Also is there anything else I should verify in that I'm missing?

Note that I've already check that they operate at the same frequency...

Thanks guys

jyz
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3 Answers3

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It may be doing this on purpose, and you are receiving the bytes correctly. They may be using randomized encryption for security -- this way no one can snoop on your receiver, and play back the data later to open your garage. The same concept is used for keyless remote entry systems for automobiles.

tcrosley
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Right, it makes sense. The algorithm used is called keyloq. There is a kind of counter that is incremented everytime you press your garage key. I let you read the Wiki page for more detail.

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I did a project like this a while back:

http://hackaday.com/2009/10/03/garage-door-packet-sniffer/

Apart from the protocol being based on rolling code or some encryption scheme like Keeloq, some of the cheaper rf modules have bad response time, you have to have some data on the line for a couple of ms before your receiver starts putting out the correct stream.

s3c
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