Try to never try resistive sensors. It is reaaly wrong way. I try to bult few resistive. No way.
I try to buld some inductive. Yes, it's possible, but lot of analog parts, difficult to calibrate. No way too.
Capacitive senors is most reliable and has a simple digital schematics.
Good luck you on your way)
PS: here is my own sensor http://vegimatics.com/products/current/
want do discuss - wellcome)