Serial communication with a car’s onboard OBD-II port
(Search for “talking to the vehicle” to get the serial commands…)
http://elmelectronics.com/DSheets/ELM327DS.pdf
- OBD codes to get current data: http://en.wikipedia.org/wiki/OBD-II_PIDs
- How to get a list of serial devices in Mac OS: http://stackoverflow.com/questions/3815211/mac-command-line-list-available-serial-ports