Note: There are several different versions of the "AstroAI AM33D" multimeter we're using, so yours may look slightly different than mine. Whichever one you have, they all work great for our purposes! But yours may have the settings or the connectors in slightly different places than the one I have in the videos. Don't worry, everything works the same.

Before you build anything, you should learn how to use a multimeter. The multimeter is, as its name implies, an electronics multi tool, sort of a Swiss army knife for measuring and testing many different aspects of your circuits.

Let's turn it on for the first time, and do the beep test:

Now measure your battery's voltage: