Re: 3C8

Posted by Karlis on Sep 07, 2016; 10:55pm
URL: http://bluesaab-forum.90.s1.nabble.com/3C8-tp9p664.html

I got a hold of an actual CD changer and did some sniffing.

We currently send this: 0xE0,0xFF,0x3F,0x41,0xFF,0xFF,0xFF,0xD0 every 1000ms (+/- 10%). I believe 0xE0 is somehow wrong in this frame as it has bits 5-7 set. From what I saw from the stock CD changer, that byte is 0x20 (bit 5 is set). This leads me to assume that:

byte 0, bit 7: 0 - sent on basetime, 1 - sent on event
byte 0, bit 6: 0 - status change due to internal operation, 1 - status change due to CDC_CONTROL frame
byte 0, bit 5: 0 - disc presence signal is not valid, 1 - disc presence signal is valid

Now this is untested and it also should include handling of a case when there's an incoming CDC_CONTROL frame. I'll do some more digging.