All of my available free time has gone into fixing the timing issue with my ECU connection code. USB latency and 1ms precision communication timing is a tricky combination. I never would have thought there was a problem with my ECU connection code, because I have used it myself for over a year. But it turns out that the 2002 S4 ECU is much pickier about the timing precision than the 2001 S4 ECU.

Hopefully a few more days of pulling my hair out while staring at the logic analyzer, and the software will be released. Too bad I can’t just use some embedded device to handle all of my communication timing issues that the USB protocol is causing me…

And that brings me to my next update. I have been thinking a lot about making my own OBD cable, and my own hand held flashing/data logging device. For the first release of my flashing software, I want to support basic dumb cables, and so I can’t rely on any fancy hardware inside the cables. But for future releases of my software I am hoping to release my own cable with additional functionality. I am hoping to do more than just use an ELM chip with some hardware support for OBD protocols. I would like to allow for additional analog inputs on the cable for data logging external sensors like wide bands, as well as support stand alone flashing and data logging without needing a PC.

I’m not sure when any of this will materialize, but I wanted to let all of you know it is something I am sorting out as a side project at the moment.