It is likely that many of us will at some time have experimented with motion detectors. Our Arduinos, Raspberry Pis, Beaglebones or whatever will have been hooked up to ultrasonic or PIR boards whi… ...

YouTube channel How To Mechatronics has created a great tutorial with full instructions on how to create your very own Arduino powered 3D wire bending machine.

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.