I realize the arduino does not provide an “INPUT_PULLDOWN” function but it would be handy.
I curently measure a 14 V max source with an analog input (A2) via a 3 resistor (all equal 10k) resistor volatge divider.
This setup works just fine until I need to measure an “open circuit” . When an open circuit occurs , the voltage measured goes to Vmax (12 volts) which is wrong … the voltage should be “0” . How can I combine this resistor network to accomodater a pull down resistor? I have included a diagram (see attached jpg resistor.jpg) which shows my idea how to solve this problem . Would the circuit labled “With Pull Down” bring the input to zero when a circuit break happens ? Or would tthe 10 Meg Ohm resistor just get ignored.