Weird Analog Input Values When Nothing is Plugged in to the Board?

notFall

Question in title. My analog inputs (with nothing plugged into them and when I have a wire plugged into them connected to nothing) return unusual values. They start at close to zero, and gradually rise until they are almost one, with nothing plugged into them. When I do try to get actual input from them, I get a ton of noise and values that I am not expecting.

Any idea why this is happening?

giuliomoro

notFall with nothing plugged into them and when I have a wire plugged into them connected to nothing) return unusual values

That's expected. These are high -impedance inputs so they need a voltage applied to them in order to return a meaningful reading. Otherwise they'll return readings based on the proximity of conductor, electro magnetic interferences from various source, the instantaneous weather conditions on the other side of the world and the background radiaton of the universe..

notFall When I do try to get actual input from them, I get a ton of noise and values that I am not expecting.

Is this with any signals actually connected to the inputs?

giuliomoro

notFall with signals connected to the inputs,

but you said:

notFall My analog inputs (with nothing plugged into them and when I have a wire plugged into them connected to nothing) return unusual values.

So what is connected to them?

notFall

Yes, that is with signals connected to the inputs, though my signals should range between 0V and 3.3V. Do you think applying very little voltage could be part of the problem? ie the voltage is so little that the electrical noise of the universe is drowning out the stuff I want to pick up?