I recently came across an article published in Circuit Cellar last year that describes a automobile Fuel Consumption Gauge. The devices ties into the OBDII system and gathers data and then actuates the gauge to display fuel consumption.

www.circuitcellar.com/advertise/ cc-advertising/Lightner-183.pdf

After reading the article I thought it might be fun to do this with a pic and PICBasic. After a little searching I found the following website which nails down the hardware side but I'm a little lost on software. (I don't read C so I am unable to port the code to PICBasic)

http://home.pacific.net.au/~ijhope/pcm/vpw_to_rs232.htm

I would assume I could read the VPW strings with Pulsin, and write with Pulsout but I'm not certain about that.

NOTE: I know about the ELM Electronics ELM322. (I own one) I'm looking to directly interface with the buss.

Thoughts, help, suggestions.