The hardware in the project mainly consists of a preprogrammed microcontroller, ELM323, from Elm Electronics of Canada.

That one is suited for the majority of cars made in Europe and Asia (using the 10.4kHz ISO 9141 protocol). Most US manufactured cars use the VPW or PWM protocols. Elm has chips for those protocols also.

The software is opensource (though only 1.04 is available for download, while the binary downloads are 1.06) and available at www.scantool.net. They also have full kits as well as bits and pieces.

/Michael