Allow 3-byte headers in Library

Please allow adding 3-byte OBD-II headers in the Library (these are necessary at least for old GM-specific PIDs for trucks from the late 1990s). Right now, the UI only accepts three nibbles (12 bits), but the backend does support 3-byte headers, and in order to use them, one needs to create custom workers in obd_manager.

(I have feeling I might have requested this already in the past, but couldn’t find the request; I remembered this when I noticed the June release had support for enhanced PIDs but still didn’t support this when I tried.)

Hi @topeju,

Excellent suggestion. I believe this is already on our roadmap. I’ll check if we can make it before the next release, which is due next week.

best
Peter

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Hi @topeju,

We need to have a few more features implemented before that functionality is available through the front-end library PIDs. We have communicated those internally and we will have them implemented as soon as possible.

In the meantime, what I can suggest, is what you’re already doing - implement them as custom obd_manager workers.

For information on how you can setup service workers, you can take a look at our guide here.

Best,
Nikola

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Just to double check: I just checked the front-end, and it now allows entering 6 hex digits for the headers, so I assume what you are referring to is that that three-byte value isn’t being passed on to the actual logger?

(I have those custom service workers set up, but would love to be able to just use the regular ones for simplicity.)

I didn’t have a chance to test this until a couple of days ago, and just to note to anyone else that might need this: this works. I can enter 6 hex digits for the headers (and 4+4 for mode & PID), and I can thus read the GM-specific Mode 22 PIDs using the front-end library PIDs rather than having to use the custom service workers.

For example, to read the Boost Pressure in my 1996 Chevy Suburban (6.5TD), I can enter 6C10F1 as the header, 2211 as the Mode, and 6D01 as the PID. Actually the 11 is the first byte of the PID itself, but that final 01 needs to be sent too (I forget what its meaning is), and the UI doesn’t allow entering 6-hex digit PIDs but Mode is immediately followed by the PID so the correct data is sent regardless.

(Which reminds me, I’ll need to mark the PIDs as shared in the Library so others can use them too.)

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