by tones111 » Tue Mar 22, 2005 3:49 pm
cboles,
I'm just getting up to speed on the openecu project, but am excited about the concept and looking for to helping out as much as possible. I don't currently have any OBD-II interface hardware, and am looking forward to hearing about the progress you're making with your interface. The picture of the cable is great, and it looks like it's going to turn out to be a very nice product. I think going the USB route is definately the right choice when looking at the current state of PC periferal interfaces.
As I'm just getting up to speed with the SSM protocol I was wondering if the FTDI chips create any sort of bandwidth limitations. It looks like the SSM interface runs at 4800 baud, so I'm assuming the FTDI drivers don't have any problems maxing that out. Using the FTDI setup is great as there is no need for driver development, and they come in a small form factor. Another option that could be beneficial down the road could be to use a PIC microcontroller (ex: 18F4550) to handle the USB transactions and reap the benefits of using a USB interface on the PC side instead of simple RS-232. Another benefit is that the Pics come in a DIP package and could provide a cheaper (aka: homebuilt) solution. The downside to all of this is that instead of a slick cable, we'd need a box to house the board. It would provide a lot more flexibility and could simplify the PC side of the software though. (just thinking out loud).
Again, I want to reiterate that I think you've come up with an awesome solution and can't wait until they become available. My thoughts were more focused at defining the long term goals of the project and where everyone wants this to go. I think we have an opportunity to really do something special for the subaru comunity and set a precedent for other auto enthusiasts to follow. I'd love to help out in any way possible and will keep my eye on things to see where I can be of use.