I want to build a sensor using arduino (or any other esp) measuring the release of a leg on a floor panel. I've build a prototype using copper plates and a BBC Micro:bit, which works fairly well. But I want to use magnetic sensors, determining release of the leg.
My education on magnetic is - simple. I know it exists. I know it's one of four basic forces in nature (ha!). But I don't know how to measure it using electronic circuits (I'm new to this topic).
Imagine one person stands on a plate, wearing magnets on his foot (say "magnetic socks"). I want to immediately detect when the person raises his leg. What kind of sensors do I need?