Re: Custom CDC to SID text
Posted by
Karlis on
Aug 18, 2017; 4:49pm
URL: http://bluesaab-forum.90.s1.nabble.com/Custom-CDC-to-SID-text-tp90p1184.html
Timpa wrote
Thanks, if I understand it correct
You send a request from "SPA" to SID 0x357 (0x1F=request,0x02=row2, byte3 priority?)
Yes: 0x1F=requesting node ID (SPA), 0x02=row2, byte3=message type (0x03=driver action)
Timpa wrote
and get a okay from SID 0x368 (byte 0=0x02(row2) and byte 1=0x12(SPA)).
Correct...
Timpa wrote
Then you send 3 lines with Text to SID from "SPA" 0x337.
Yes. These three frames include message sequence, type (sent on an event or basetime), address of the SID and 5 x bytes of an actual text. Note that everything larger than 12 chars of the text will be zeroed out as that's all SID can display on a single line.
Timpa wrote
Hope I have get the principle right

Yes, you got the idea right.
Timpa wrote
Have you tried to use ACC instead of SPA ? ACC only uses SID when you make
some changes or calibrate.
This can be done on behalf of any node on the car. The trick is to find and pick one that's not installed. The thing is that when a node is not interested in writing on SID, it has to send out a specific frame telling so. Then, when node is interested in writing on the SID, it starts asking for a grant to write. The SID then decides who and when can write. So even if ACC is used, you could, theoretically, send a request to write, but then the "Actual" ACC will also push out a frame saying that it doesn't want to write. So SID will be confused receiving two frames, supposedly from the same node with confusing requests. This can lead to all sorts of problems. From flickering text to SID going dark and the need to pull the fuse...
On my and Seth's car there's no SPA, so we have all the necessary means to pretend to be one and everyone else on the bus are happy as our requests/text sending don't interfere with anything else.
Good luck!
2001 9-5 SE V6; 2006 9-5 Wagon; iOS; BlueSaab version = "latest and greatest" :)