Corvette CCM Reverse Engineering Anyone?

[spfautsch]

isn't this actually 64 microseconds per tick, thus making 28 ticks 1.792 milliseconds? Check my work.

System Clock: 16000000 Hz
TCCR3B = 16000000 / 1024 = 15625 Hz
1 tick / 15625 Hz = 64 microseconds/tick
64 microseconds * 28 ticks = 1.792 milliseconds

Your math is correct. The 62.5 us period comment was copied and pasted from an example I found somewhere, and I never bothered to verify even though I have a 1024 prescaler in the diy-ltcc code that is showing the correct time period.

The 1.792 ms / 28 ticks may need more fine-tuning. I found that when the controller was writing to a file without echoing a bunch of debugging noise to the console, this value had to be increased. In other words the time involved in sending to the console was creating a delay that has to be accounted for in order to get the fastest acquisition rate. Sd card write latency is another factor (though much smaller).

Something I have been waiting for a long time. Definitely will build a test rig and get the opportunity of blackbox logging.

Some help on the setup will be highly appreciated. I am in no hurry, a good winter project.

I'm sure it could be adapted to work with the PCM as bus master, but I don't see myself having the ambition to take this to that level. I have a date this winter with a d/a, a crap-ton of sandpaper, primer, paint, etc. I'll probably put a page up on my wordpress site for it and link to it from my .sig. but that might be as far as that goes.