An Arduino can measure time, a coil and a resistor will create a delay proportional to the circuit values, and metal around the coil will change the coil’s inductance.

[Mircemk] has an example that bends both worlds, with a single transistor oscillator and an Arduino. This type of metal detector has a large search coil which forms part of the tuned circuit in an ...

Last Updated: 7/24/18 Teaching Standards: This is an Arduino project called Fruit Detector. The idea behind the project is pretty basic. Different fruits have different resistances. The fruits can be ...