Ok, ive captured the signal into a wav file and.. its not what i expected. i thought i would have neat little packets but instead i found this.. what did i do wrong?

 

What is the purpose of this thread?

I thought you wanted to identify the signal and build your own key fob. While that is probably not cost effective, it could be fun. Steel-Line is a current manufacturer and parts are available. Why not go in that direction?

BTW, as you are a renter, does the landlord approve of renters duplicating the key fobs? It is easy to imagine that a landlord would want to control duplication of door keys and garage access.

 

this project is for fun, i know i can buy a cloning device for like $5 from aliexpress. and yes, the landlord is very aware of my intentions.

 

Now that you know the approximate frequency, time to have fun. Forget about that part and decipher what the RT1762PN does. You can carefully probe its pins and see the code. Then write a program to reproduce it. It may work to simply copy a coded signal, but there is a good chance that won't work for security reasons.

Probably more likely, it is a rolling code, so you will need to figure out the algorithm. Microchip makes several encoders, but I believe it tries to keep the algorithms secret. The RT1762PN datasheet would be the most help. If the encryption is hard coded in the RT1762PN, then it will probably be quite a challenge to duplicate with an arduino or other MCU. I highly recommend reading some Microchip publications about its KeeLoq technology to get a feel of what you may be facing: https://www.microchip.com/design-centers/embedded-security/technology/keeloq-technology

An oscilloscope can help unravel a code, but a logic analyser may be more help. As standalones, logic analyzers are not that expensive, and even some low-end oscilloscopes incorporate them.

 

its not what i expected

Nor what I'd expect. Looks like you have a stereo version of the fob!

 

Ok, ive captured the signal into a wav file...

Are you sure? How do you know?

 

I Can only see a tiny bit of the transistor label and can make out 'H1'

Okay, there it is- that's the Transistor. I can get the IC for $2.60 each, but am still waiting for responses for the data sheet from vendors, and the OEM.

 

@Andrewlapham

OK... so.... I've managed to track down the original Taiwanese company that made this transmitter, using this IC by RATO. I've not been able to track down RATO themselves- they are long-gone.

While I do not have a schematic for your FOB, I do have one for another they made circa 2003, using the same IC, but 4-button. The important thing here is that I was able to track down a schematic identifying its pin-out, and more importantly, the antenna circuit- yours uses the same component principle.


I couldn't reverse engineer your circuit, because I can't see the traces clearly enough on the component side of your PCB.

Hopefully the above will give you enough to do what you need. The transmitter I found info for is listed under their FCC filing- here is the link (contains more info):

https://apps.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=sa4cRQNLqNkZLRqy2m6NwQ==&fcc_id=Q9K-PC20-01

 

From the operational description:

 

About measuring there are two or three alternatives
1) RF SDR USB stick, bug-full installation to pc and You have a high accuracy spectrometer up to 1.7 GHz.
2) Hack-RF One, the same painful installation and You have ultra++ spectrometer from 50 kHz up to 6 GHz.
3) GoQ-390 and You have ready to use spectrometer up to, hmmm, range of sensitivity was 6 GHz, but spectrometer ends faster, I think it was 2.4 GHz. First boths are capable to decode the deciphered hidden codes into signal. Second is able to reproduce em