LinkIT ONE Capacitance Meter

Capacitors can be tricky. Sometimes the labeling on the side of them can rub or melt off and now you're stuck with a capacitor that you don't know the capacitance of. In this guide, we'll go through how to set up a circuit that can measure the capacitance of your unknown capacitor and help you get your lab nice and organized.

We'll be using the LinkIT ONE, which is a like a super charged arduino. One of the biggest benefits is built-in grove sensor support, which will come in handy for easily printing out the capacitance .

• LinkIT ONE
• 220 ohm Resistor
• 10k ohm Resistor
• Grove RGB LCD
• Capacitor of unknown value

You'll also need some jumper wires and a breadboard for speedy prototyping.

Now, let's wire together our circuit. The basic principle of this project is measuring how long it takes the LinkIT ONE to charge the capacitor to 63.2% of its total charge. We then use some great physics equations to calculate the capacitance of our mystery capacitor.

Follow the diagram above to hook up your mystery capacitor like the circuit shown. Then, make sure to plug in your Grove RGB LCD into the Grove slot directly on the LinkIT ONE board.

IMPORTANT NOTES FOR BIPOLAR CAPACITOR

- On the capacitor, there is a side with a silver stripe. Make sure that end is connect to the Ground.

Now that you've created the circuit, download the attached code file and deploy it to your LinkIT ONE.

The code will calculate the capacitance of the capacitor using the principle of an RC Charging Circuit. If you would like to read up more about how exactly it does this, I would read over the code and then check this resource.

Now that we've deploy everything, it's time to measure the actual capacitance. Once your code has deployed, your RGB LCD should print out what the capacitance of the capacitor is on the screen. Feel free to swap out different capacitors and see which are which! Make sure to let each capacitor sit for about 10 seconds to give the circuit time to properly settle in on an answer.

Hopefully this tutorial has provided you with both a useful science experiment and a handy way to organize your lab with the LinkIT ONE. This application could could go to great lengths to give us more insight on electronic theory. If you add capacitors in parallel and in series, what kind of things to do you observe in our RC Circuit? Keep all your notes together in a journal and compare them with textbooks to see if you understanding is correct!

References used:

RC Charging Circuit

Arduino Capacitance Guide

HyperPhysics: Charging a Capacitor

RC Time constant - Wikipedia