Remove filter from sniff-mode

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radiokonntas
Posts: 1
Joined: Wed Dec 13, 2023 8:52 pm

Remove filter from sniff-mode

Post by radiokonntas »

Hi,
is there a way to remove any Filter from sniffing mode. I want to be able to monitor all of the traffic on the can bus not just the ones with the header 7E*. Becuse data like this won't help:
[47763] 00 00 07 E9 08 06 41 00 98 18 00 01
[55263] 00 00 07 E9 08 06 41 00 98 18 00 01
[59762] 00 00 07 E8 08 06 41 00 98 1B A0 13
[64262] 00 00 07 E8 08 06 41 00 98 1B A0 13
[67263] 00 00 07 E9 08 06 41 00 98 18 00 01
[70262] 00 00 07 E8 08 06 41 00 98 1B A0 13
[71763] 00 00 07 E9 08 06 41 00 98 18 00 01
[74762] 00 00 07 E8 08 06 41 00 98 1B A0 13
[79262] 00 00 07 E8 08 06 41 00 98 1B A0 13
[82263] 00 00 07 E8 08 06 41 00 98 1B A0 13
[86763] 00 00 07 E8 08 06 41 00 98 1B A0 13

Maybe I should I add a few steps I tried to remove the filter:
remove the obd.setHeaderFilter() and obd.setHeaderMask() functions.
Changed the filter functions to the following:
obd.setHeaderFilter(0x000);
obd.setHeaderMask(0x7FF);
also removed the code in the library in case it gets called by a different function with a default value of some sort.

None of this removed the filter.
Thank you in advance.
ulnaoperating
Posts: 1
Joined: Wed Apr 10, 2024 11:31 am

Re: Remove filter from sniff-mode

Post by ulnaoperating »

You are on the right track! It appears that you've located the filter routines (setHeaderFilter and setHeaderMask) that restrict the CAN bus data you see to messages with a specific header (0x7E*).
sodacurve
Posts: 1
Joined: Wed Apr 17, 2024 8:09 pm

Re: Remove filter from sniff-mode

Post by sodacurve »

That's precisely where you're at! You seem to have found the setHeaderFilter and setHeaderMask filter functions, which limit the CAN bus data you view to messages with a certain header (0x7E*).
andreen
Posts: 1
Joined: Wed Aug 21, 2024 5:18 pm

Re: Remove filter from sniff-mode

Post by andreen »

Look into the library you're using to see how it implements filtering. Sometimes, filters might be hard-coded or applied automatically. If necessary, modify the library to remove or bypass these filters. fnf
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