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g3gg0 / ESP32_CRSFSniffer

MIT License
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TBS Tx packet #7

Open anitasusan opened 4 months ago

anitasusan commented 4 months ago

Hi @g3gg0

I have been studying your blog on the analysis of tbs cross fire with respect to air transmission part of tx and rx of a tbs system described in the link https://www.g3gg0.de/fpv/fpv-analysis-of-tbs-crossfire/. Thank you for the detailed blog, it is very helpful. Is the packet structure expected to be the same for both serial and air transmission? For eg, I am unable to get any packet types and flags from my decoded bytes as shown below for a tx air stream. 'FC87B859B7A1CC24575E4B9C7D' 'FC220259B7A1CC24575E4B9CE5' Would you be to share few more info particularly for air transmission.

Thanks

g3gg0 commented 4 months ago

the air protocol is totally different. also from the blog: "Interesting is the fact that over the air only 10 bits of resolution is used whereas the serial protocol uses 11 bits."

anitasusan commented 4 months ago

Thank you @g3gg0 . Does that mean the packet sizes are different too? I was hoping it would follow the CSRF protocol format

g3gg0 commented 4 months ago

totally different -> yes, totally different :)

anitasusan commented 4 months ago

Thank you @g3gg0 , I am able to extract few telemetry data now from air. I dont see all the csrf header data types such as 0x28 and 0x29. I read on the blog that you noticed that the unit was sending all config options over air. Do you by any chance have a test data from which the following data was extracted Screenshot 2024-06-06 153422

g3gg0 commented 4 months ago

Well, i have no more than the screenshots on my blog. The payload on air is enveloped differently from the crsf protocol on the serial interface.