Re: Custom CDC to SID text

Posted by Karlis on Aug 18, 2017; 6:40pm
URL: http://bluesaab-forum.90.s1.nabble.com/Custom-CDC-to-SID-text-tp90p1186.html

Thanks for the update, Petter!

Yes, from what I've seen this works fine(-ish) on IHU's with Navigation. The problem I've seen with this approach on my non-Navi IHU is that for every "driver action" (0x03), IHU briefly takes over SID no matter what gets displayed on it, because, of course, it has to show that there's been a switch to the next track/CD. So the flickering is more frequent. One way to suppress this is by using 0x01 (Engineering Test) as request type, but that prevents anything else (even ECU and "broken" light bulb messages) to get through when a need comes.

Also, even though SPA and ACC are nodes of "higher" priority (their frames always win CAN bus arbitration), that doesn't mean that they can push through when they need to. Meaning:

If SPA/ACC gets access to SID, IHU (even with lower possibility to win CAN arbitration), goes like "hey, I know I'm of lesser importance here at the moment, but I have this text I need to display because it came as a result of a driver action". So SID then gives grant to IHU.

Hope this is not too confusing...