Setting up RF Sniffer correctly for 433 MHz

[andria...@gmail.com]

Hi fellow RF Explorer Fans,

I tried to use the sniffer feature of RF Explorer for Windows together with a 6G Combo RF Explorer Spectrum Analyzer (7 Button Model) to capture 433 MHz signals.

The 433 MHz device I'm using is a very simple remote control which has 5 button pairs to switch some remote controlled outlets on and off.

What I want to achieve is to get the codes from the remote control to use them in some arduino home automation project.

I was able to capture signals inside the sniffer after pressing a button on the remote control but I'm not sure what I just captured. I looked up a lot of screenshots of captures of remote controls like this and this model should transfer 24 bit messages like most of these do. But my captures didn't look like any of these.

As far as I can see, there are not much options I can play with inside the sniffer module. The FRQ is set correctly to 433,92 MHz as indicated on the back of the RC. The threshold of -70dBm also seems to be correct because with higher thresholds I got no capture. Only with -70dBm or lower.

What I have no idea of which value to set it is the sample rate. Per default its set to 60150. Is this a good value? Some forums for other 433 MHz sniffers did suggest rates of 9600. I also tried lower rates like 9600. The capture did look different then but still wasn't similar to the screenshots of other 433 MHz devices.

Maybe somebody here can help me out with the setup or understanding the readings?

I attached screenshots of 3 subsequent readings of the same button pressed.

Thank you and regards,

Andrian

[andria...@gmail.com]

I forgot to mention that the messages not only look different to expected forms of readings but also look different with every time I press the button. Normally I would think that there is a lot of interference in the background but without pressing any button on the RC, everything looks normal. No 433MHz signals around above the noise floor ~-90dbm.

[Julián Calderón]

Hi Adrian,

Currently, decoders for PT2264 remote controls and Oregon Scientific weather station are included but you can can develop your own add-in to decode it by downloading the latest RF Explorer for Windows version from www.rf-explorer.com/download and checking instructions in the documentation included.

Please go to C:\Program Files (x86)\RF Explorer\RF Explorer for Windows\sniffer_addin. There,  you can find a source code of Oregon V2 protocol which you can use as starting point of your project.

[Julián Calderón]

I forgot tell you that your capture may be a PT2264 protocol so try with this first. See specific zip file with all required details included in the installation package

Best Regards,

----

Julián Calderón

jcal...@rf-explorer.com

El jueves, 8 de octubre de 2020 a las 16:28:55 UTC+2, andria...@gmail.com escribió:

[andria...@gmail.com]

Hello Julián,

thank you for your quick response and awesome hints to further ressources. The documentation included in the installation package is much more detailed than the ones I found online so far. It also describes the capture process in detail.

I tried the PT2264 decoder you mentioned already before but it didn't work out and only resulted in an error message. So I assume it's no PT2264 based device.

I might want to try to build my own decoder but before doing this I wanted to make sure I get readings which do make any sense to me.

In my understanding the readings should always contain similar looking parts if I press the same button on the remote control. But they don't. And that's why I started this post here.

But with the documentation I'm now able to at least make sure my setup is correct so I can exclude any errors on this for my further research.

I will do some more experiments with the additional knowledge I got from you and maybe ask some further questions afterwards. I hope this is fine.

Wish you a great day!

Thank you and regards,

Andrian