This tutorial will cover those wonderful blinky things, LEDs. We're going to cover how to calculate the current going through an LED and in the mean time introduce two important laws of electronics, Kirchhoff's Voltage Law and Ohm's Law. We'll begin by performing experiments that will demonstrate how voltage and resistance affects current and then prove those results with a little math.

There's no coding involved in this exercise, and although we use an Arduino in the images, you don't need one to follow along. We do suggest some other kind of power supply so you can try out the experiments, but you can use even batteries in a battery holder!