I want to take readings from various Auto sensors in a car and report on them via LCD or whatever, like Engine temp, Fuel level, Vacuum pressure, MAF sensor reading, MAP reading, RPM's, blah blah blah
most of these sensors have 3 wires, one is GND, the other is +12V( or whatever voltage V+ is at), and the last is an analog value between the two. I want that analog value, and give it a meaning.
You have 12-14.5 volts going into the ECU which regulates all of those sensors down to 5 volts max. I would pull some to check but all of the ones I have seen are like that.
I am building a similar set-up for Vacuum/boost, O2, coolant temp, intake air temp, voltage.
Jim
Holland, MI