How to analyze this signal?

[probono]

I would like to recreate a 27.145 MHz signal of a BOSE Lifestyle RC-9 remote control with Arduino. For this, I would like to analyze the signal with Gqrx. So far, I am able to see "something" in Gqrx https://gist.github.com/probonopd/c114ea42ea6fef5b6b6b6118ae49ebf8 but how would I determine the exact timing of this signal so that I could recreate it with a microcontroller? In the picture, I pressed different keys but the signal looks more or less the same. Is there a way to get more precise measurements (in milliseconds)?

[David Ranch]

Though Gqrx is a great tool, it's not the right tool for what you're trying to do here.  I encourage you to research tools like "inspectrum", "baudline", etc. which are purpose built signal forensic tools.  There are lots of tutorials out there on the web that tell you how to use these advanced tools and I bet it would be easier to prototype things using GnuRadio vs. trying to do it on your Arduino.  Up to you.

Btw.. don't assume this signal is FM.  If I was doing this project, I would find the equivalent of the FCC ID of the transmitter and look at the mandatory public documentation on what it's transmitting.  Sometimes the documentation is very detailed but other times, they only state the actual mode (OOK, whatever)

--David
KI6ZHD

[David Ranch]

Btw, signal reverse engineering is complex but there is a lot of materials out there.  Some of my more favorite comes from Balint Seeber:

   https://www.youtube.com/user/balint256/videos

--David

KI6ZHD

[probono]

2016-11-27 21:28 GMT+01:00 David Ranch <dra...@gmail.com>:
> Btw.. don't assume this signal is FM. If I was doing this project, I would
> find the equivalent of the FCC ID of the transmitter and look at the
> mandatory public documentation on what it's transmitting. Sometimes the
> documentation is very detailed but other times, they only state the actual
> mode (OOK, whatever)

Thanks David for your spot-on pointers.
Using the name of the manufacturer and a search for 27.145 MHz in the
FCC database I found that the device is using OOK and even see example
pulse trains. Do you happen to know the easiest/cheapest way to
generate 27.145 MHz OOK signals?

[David Ranch]

Well, by law in the US, any transmitter will have a specific FCC ID.  Searching that FCC ID will get you the specifics of that transmitter to various levels of detail.  Maybe going that route will get you more information (really depends).  As for how to create compatible OOK signals, that totally depends on the symbol rate, etc.  You'll need to analyze the signal and/or the FCC docs to know what's needed.  After that, there are lots of off the shelf ISM transmitters that create OOK signals : https://www.google.com/search?q=ISM+OOK+transmitter .  I don't know what it would take to get say an Arduino, PIC, HackRF, whatever to create these signals but I'm sure there are many other email lists out there that you could consult with.  I *don't* think that the Gqrx list will be a good resource for that as it's a receive-only application focusing on common amateur radio modulation schemes.

Anyway.. good luck with your project!

--David
KI6ZHD