433 MHz car remote signal determine

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Makkok
Posts: 1
Joined: Fri Apr 06, 2018 12:19 pm

433 MHz car remote signal determine

Post by Makkok » Fri Apr 06, 2018 12:27 pm

Hi All!

I am quite new with the RTL-SDR, I try to capture and decode my car remote, but I receive strange waves - at least strange for me. Could you please someone identify what type of signal is it? I mean AM/OOK, FSK, etc.
Many thanks!

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Username
Posts: 273
Joined: Sun Oct 09, 2016 7:27 am

Re: 433 MHz car remote signal determine

Post by Username » Fri Apr 06, 2018 8:25 pm

The best is if you ask in a Car Forum for.

rtlsdrblog
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Joined: Mon Nov 19, 2012 11:54 pm

Re: 433 MHz car remote signal determine

Post by rtlsdrblog » Sat Apr 07, 2018 4:09 am

Most likely AM. Record the sound in an audio processor like Audacity and zoom into the audio signal. That should give you a hint as to what encoding it is.

LarryW
Posts: 1
Joined: Tue Jun 12, 2018 10:44 pm

Re: 433 MHz car remote signal determine

Post by LarryW » Tue Jun 12, 2018 11:04 pm

If you have an FCC ID for the remote you can try searching it on the FCC's site and see what documentation is available for it, which might include all freqs. it uses as well as modulation type and other design info. For example, here's what one of the documents found for my remote contained:

"CIRCUIT DESCRIPTION TRANSMITTER
The hand-held RF transmitter consists of the housing, three or four control buttons, microcontroller, an UHF oscillator (Colpits configuration) and a 3 volt battery. The microcontroller uses an internal oscillator running at 4.0 MHz, and the RF oscillator uses a SAW based oscillator to resonate at 315.0 MHz. The modulation format used will be ASK, with a Rolling/Manchester code data format. Once the user presses a button power is applied to the microcontroller which turns the RF oscillator on and off at the rate of the Rolling/Manchester code data being sent. The signal is then sent to the receiver module via RF data transmission. The module will then act upon the RF data received and will perform certain functions in correspondence to which transmitter button is pressed."

NOTE: At least when using my tablet, the files are all downloaded with the same name and have an .html filetype, so you may have to at least change the .html to whatever type of file they are listed as being (i.e. .pdf).

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