Using a Multimeter #
The multimeters in the hatchlab have multiple modes in which they can operate that allow a range of measurements and diagnostics on a circuit.
Continuity #
Continuity is when two locations in our circuit are electrically connected. Sometimes it is important there is continuity such as in the connection between an arduino and an LED. Sometimes it is important that there is not continuity, such as between 5V and GND which would represent a short circuit. Our Multimeter will allow us to quickly check our wiring is correct and that the components that should be connected are, and those that should not be connected aren’t.
To access this mode, turn the dial on the multimeter straight up pointing to the 
symbol. Now when you touch the metal tips of the probes together, the multimeter will make a sound.
You can now touch any metal parts od your circuit. If the two metal parts you touch are connected, you will hear a beep, otherwise you won’t hear anything.
Electricity Explainer #
For the rest of the readings to make sense we need to understand a bit about electricity. We used ChatGPT to generate the following explainer on Electricity, in the context of multimeters.
Think of the water in the hose as electricity again, and squeezing the handle as voltage — the push that makes the water move. Now, current is like how much water is coming out of the hose. More water means more current; it’s like having a bigger flow of electricity.
Resistance is like anything that makes it harder for the water to flow through the hose. Imagine if there were kinks or bends in the hose, or if the hose was very narrow in some parts. These kinks or narrow parts are like resistance in an electrical wire; they make it harder for the electricity (or water) to flow through.
When you use a multimeter to measure an electrical circuit, you’re checking three things:
Voltage - seeing how hard the electricity is being pushed through the wires.
Current - measuring how much electricity is flowing.
Resistance - figuring out what might be blocking or slowing down the electricity.
Just like when you’re using a hose, you need to know how much water is coming out, how hard you’re squeezing, and what might be stopping the water from flowing smoothly. Using a multimeter helps you understand all these things about electricity when you’re checking circuits!
Voltage #
To measure Voltage we set the dial to the V 
(Voltage DC) setting, connect the probes to either side of the component we want to test, or to each side of a battery or power supply.
Be careful not to use the V 
(Voltage AC) setting, this is for alternating current which we don’t use.
Current #
To measure Current we can must connect the multimeter in series with the rest of the components in the circuit. I find it easier to use a Power Supply to measure current as it can also provide power at the same time and measure.