Hello

[sp372]

Hello again, these project can decode OOK Manchester Thomas data? Thanks

[roberttidey]

The software does not do any specific decoding. The data capture function collects the raw data as a sequence of raw OOK pulses with the pulse widths logged so they can be examined and the method used to encode bits and then messages can be discovered.

There are numerous coding schemes used in rf 433MHz devices with Manchester being just one example.

What I normally do when faced with unknown devices is to open capture files in a spreadsheet and then use it to process the pulse widths to produce meaningful data.

It would of course be possible to write a specific decoder in the device but that would make it very specific rather than the general analyser it was intended for.

[sp372]

I have the code for the decoder from rtl 433 github how to implement?

[roberttidey]

The RTL433 has a lot of protocols supported and is designed to be used with the USB SDR dongles running on more powerful platforms.

It may be easier just to code a specific Manchester decoder from scratch if that is what you are trying to do.

It would be fairly straightforward to add such a decoder into the current rf433Analyser code. One can add extra functions to the current code by adding a new web url calling function just like the current save raw data function. That would then do the equivalent of the raw data capture but pass it through a decoder before saving the result to a file.

Few questions would help me give a more targetted answer.

1. What is your end aim here?
2. Which of the RTL433 devices are you trying to support decoding for?
3. What level of expertise do you have in coding? E.g. arduino code, javascript.

[sp372]

Hello I like that you can help me in my project. I tell you I want to make a team that is able to read Schrader brand pressure and temperature sensors that They come on the wheels of a Smart ForTwo 451 that unfolds them on an OLED screen To incorporate it into the dashboard of the car, using an Arduino Due or Arduino Pro Micro or Seed Xiao or esp32 using the Arduino IDE and the c1101 transceiver or the RXB6 or the MX-05V, I have a little bit of Experience programming in that environment. The TPMS sensors are already studied and the code is ready to read them on the github page: https://github.com/merbanan/rtl_433/blob/master/src/devices/schraeder.c However, I have not been able to implement a code for the project I have in mind, and I have tried to understand the demodulation and decoding of those sensors, that's what I'm in. These are the references I have: https://www.youtube.com/watch?v=13vPuve_be0&t=466s https://www.hackster.io/jsmsolns/arduino-tpms-tyre-pressure-display-b6e544 Thanks for the attention!

[roberttidey]

OK I understand a lot more now.

The project here is not a good starting point for this as it focuses on measuring the signal strength and capturing raw data in order to understand unknown protocols.

The hackster project is a much better starting point and seems to provide most of what you want. Have you tried using that? It should be fairly straightforward to port to other platformslike esp8266 or esp32.

Note that you do need to use a cc1101 module to capture the data as it looks like the sensors transmit their data using frequency key shifting not OOK.

I am quite interested by this hackster project as I have a Toyota Prius where the sensors just trigger a warning light rather than give full details (like described in first part of article). I think I may get a CC1101 module to see if I can get this to work with a esp8266 or esp32

[sp372]

Excellent I will be pending your project, thanks for the help now I will focus on what you mention to start from there

[roberttidey]

I have got the Hackster project to compile in a ESP8266 environment. I had to add ESP8266 as a supported CPU and to replace the Ticker library with the TickTwo as the standard Ticker library with the ESP8266 is not compatible.

I can do a little more tinkering but I won't be able to anything significant until I get the CC1101 module which will be a couple of weeks.

[roberttidey]

I have added a new repository at https://github.com/roberttidey/Schradertpm to handle development.

Note that this does compile but is completely untested until I receive the CC1101 hardware.

Please add any further comments under the new repository.

[roberttidey]

See first issue in schradertpm repository for progress report on that.