Using Digital and Speed Inputs for Var Resistance Sensors

[Herrubermensch]

I have a CDL3 dash with the 12 I/O and logging options enabled. I currently am using two digital inputs and two speed inputs for switches: next line, previous line, mode and alarm cancel. But I am about to hookup a CAN-based keypad to control these switches, which will free up the related digital and speed inputs. I would like to use those digital and speed inputs either for two-wire variable resistance sensors (AIT and fuel level) or three-wire analogue voltage sensors (fuel pressure), as I already have used up the two analogue temp sensors inputs and all four variable voltage inputs for other sensors. Is this possible with some combination of pull-up and pull down resistors or do I need a more complex conversion circuit? Is this game worth the candle? Any assistance would be appreciated.

--Peter

[Herrubermensch]

For the benefit of other readers, I have learned that this would require a micro controller and programming and is not, as I suspected, a worthwhile endeavor. It has been suggested that instead I should use a 0-5 volt to CAN converter for expanding the inputs on a CDL3. I am currently exploring that option and will report back if it works.

--Peter