i will test that. i'm also thinking that a standard refrigerator magnet is not strong enough with this setup. i will take a flux meter to measure the gauss with a rare earth magnet. to my knowledge, there is no specific magnetic sensor to sense a magnet through a magnetic material. do you know of any? thanks again!
the specifics of what I'm making:
A 10" by 6" perforated steel plate. Behind the plate, 5 leds, a little over 1" apart are arranged in a column. Each led represents a certain target point. The magnet that the user is able to move is on the other side of the perforated steel plate (it is important that there is an attraction b/t the magnet and the surface it's traveling on). I want the sensor, whether a reed switch, a unipolar or omnipolar hall effect sensor (or other that I don't know of ) to be able to read whether the magnet is located over led 1 or led 2 or led 3, etc. all reliably.