J1939 Digital Annex to DBC about canmatrix

[ebroecker]

Hi @mattie47 ,

I am quite sure, canmatrix cannot do the conversion.
I never ha a DA in my hands, so I'd wounder if this works...

But maybe it's not to hard to implement, if I could get some basic information about this xlsx.
things like column-headers would help a lot

[mattie47]

Thanks Eduard.

Slide 76, and slide 77 have a couple screenshots of the historic xls 2020 version:
https://www.cybertruckchallenge.org/wp-content/uploads/2022/06/Introduction-to-SAE-J1939-CyberTruck-2022.pdf

I'm not too sure how much can be shared, but I will see if I can provide a sanitised file with just the headers etc.

Worthy of note for https://github.com/nmfta-repo/pretty_j1939 is the author had always intended on trying to make it work with canmatrix (see last section of the readme).

https://github.com/andrewdodd/decoda is another tool which also built on pretty_j1939:
However, if you own a copy of the SAE Digital Annex (link), then this library provides a number of bundled scripts to convert the XLS file to a suitable JSON spec file. The code for these scripts borrows heavliy from the pretty_j1939 library, but it has been adjusted to work in a slightly different way.

[MatinF]

We convert the J1939 Digital Annex to DBC format for every new revision, in a legal collaboration with SAE. You can purchase the DBC file here: https://www.csselectronics.com/products/j1939-dbc-file

In my opinion canmatrix is not well suited to handle this as the J1939 DA is filled with various syntax inconsistencies and issues. It's a lot of manual work to ensure the output is right.

[mattie47]

Yeah it's quite a pain unfortunately. I wish I'd reached out here first to confirm what exact support there currently was, rather than just buying the spreadsheet. Things seem to be a lot simpler when they're in a DBC file for consumption in other tools, rather than the XLS/XLXS directly from SAE.

We had some shifting priorities internally so I haven't had a look at this much further.

A colleague did make a couple minor changes to pretty_j1939 to make it work with the latest DA though, however this was a pretty minimal change, and still requires converting the XLXS to XLS first:

https://github.com/SherifRiad/pretty_j1939