Hey ACCLR8N! So I'm trying to do something similar to what you have achieved here but adapt it to work in Android. Your work is the most documented conversion I could find thus far but is still a little confusing to a newbie like me. So far I've looked at Fusion Brain, Phidgets, and the Arduino for potential boards but I'm not sure which is best.
I've got a 1993 Jurassic Park Ford Explorer replica and all I need to read is oil, fuel, temp, voltage, and speedo since I'll just get rid of the tach and relocate all my dummy lights. Once I find the resistor values for all the gauges (working on that!) is it simply a matter of adding the correct resistors to each wire before tapping into the microcontroller? Could I take a look at your wiring notes?
Any help would be greatly appreciated. Thank you!