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.

How It Works The LDR is connected to a voltage divider circuit to produce an analog signal proportional to the light intensity. The analog signal is read by the Arduino via pin A0. The program ...

[Lord Feistel] gives us a demo of how this could work with nothing more than poorly designed code, a resistor, and an oscilloscope. The hardware side is, as mentioned, really simple.

The LDR (Light Dependent Resistor) sensor changes resistance based on the light intensity. In this project, the LDR is connected to an Arduino Uno to automatically control lighting. When light ...