This seems like a stupid question, but I can’t figure it out. Say I have a potentiometer with a 3 pin connector on it (VCC, GND, and the variable output which will go to an ADC pin on the Arduino), is there any way to detect whether it’s connected or not, with just those 3 pins?
Attached is a diagram to clarify, as well as how I would do it using a 4 pin connector and a digital I/O pin with its internal pullup resistor turned on. But it seems like it should be doable with just the 3.
To be clear, I don’t mind using another Arduino pin. It’s the connector that I’m trying to keep minimal. Also, the fixed resistor could be moved to the Arduino side if that makes any difference.