Great stuff, Colby. Now just a couple of more questions, if I may.
Serial comms talk about marks and spaces, whereas the KWP2000 spec deals with high (idle) and low voltages. How do the two correlate? Is mark the low voltage spec? Or is space?
Serial comms also mention a start bit (which is a space) and stop bit/s (designated by a mark). Does the actual hardware device on the vehicle end send the serial comms start bit? Is the device really just the output of the RS-232C signals brought down to the signal level of the K-line spec (12V or something)?
I do apologize for the questions. As I've mentioned, I'm pretty new to serial comms programming and I try to limit my questions to the non-generic ones (ie. cable-specific).
I would use SSM, but the only documentation available,
http://www.brendan-stewart.com/other/subaruecu.htm , on it only give a subset. I don't know where else to get more information on SSM short of disassembling the ECU ROM. I'd love to help on that end if you'd like to assign me some code blocks to go through. The only reason I turned my attention to OBDII now is that I hit a brick wall on the SSM front. I can pick up HC16 assembly and disassemble, but I still have to be supervised.