Up until now you've learned how circuits work and explored Makey Makey. But now let's go further by exploring switches. Switches are a simple type of sensor. Sensors and microcontrollers power our world. But what is a sensor? And what is a microcontroller? And how do they work together? Let's get started!
|Sensors, Switches, and Makey Makey, oh my!
Welcome to the Maker Class! This is a class for students who've finished our Beginner Level Makey Makey class or makers who already have basic knowledge about Makey Makey.
In the beginner classes, you learned how circuits work, explored Makey Makey, and made drawings as the signal to play piano apps. But did you know that you can create complex sensors with Makey Makey?
Let's start by making a few simple switches.
A switch is a simple type of sensor.
Vocabulary: A sensor is an input device that senses something (water, light, motion, sound) and then signals that information to an output device.
Example: Your drawing from this lesson was an input device, when Makey Makey sensed you touching each drawing, it sent a signal to your computer where Scratch or the piano app received the signal and played a piano note!
When you start designing your own sensors, it is good to think of the process as a conditional statement “If This> Then That.” A light sensor might sense, “if there is light, then turn off the night lamp.” It could also sense, “If there is darkness, then turn on the night lamp.”
Sensors combined with Makey Makey
When you connect a sensor to a Makey Makey, you can detect specific types of information and adjust what you want the output to be with the code that you create.
The Makey Makey board has 6 “inputs” on the front that function as your computer keys. When an Earth input detects a key press input, you complete a circuit.
This information travels through the red USB cable to tell your computer, “Hey! The space key was pressed!” Since Makey Makey allows you to tell your computer that everyday stuff is now your computer keyboard, you can “make” any conductive thing (like a banana) one of your computer “keys.” That’s why it’s called a MaKey MaKey!
People use sensors with Makey Makey and other microcontrollers like Raspberry Pi, Arduino, and micro:bit, but you can actually create your own sensors out of simple materials to use with any of these boards.
When you play the drawing piano you are the EARTH connection that closes the circuit as you press on each drawing to make each piano key sound.
Now let's learn how to create your own switch that doesn't require bare skin to complete the circuit.
Vocabulary: A switch is a component that requires a physical action to close a circuit. Just like the keys on your keyboard! A Switch can be momentary or maintained.
Let’s make a momentary switch first. This means the switch will only be “on” as long as the switch is actuated. Normally a switch is an open circuit until it is actuated. Meaning the circuit is open until you push the switch to activate it. Just like a keyboard button, or a calculator button. Did you know that you can draw a momentary switch?
You can also easily make a maintained switch with office supplies. A maintained switch remains on once you turn it on or off once you turn it off. Just like a light switch in your house.
The best way to learn about switches to make a few different types.
This craft along video will show you four different ways to craft your switches!
Create a Momentary Switch with a Pencil Drawing!
You can draw a switch very easily! You just need two separate drawings that will only touch when you close your paper together. Attach one drawing to EARTH and the other drawing to SPACE. When the two drawing touch, the SPACE light on your Makey Makey should light up!
Make sure your drawings uses a lot of graphite (that's the pencil lead)! Fill in your drawings completely with graphite as the drawing is actually the circuit! The graphite is the conductor that allows electrons to flow in your Makey Makey powered circuit.
When the two drawings touch, you create a closed, conducting loop that allows the electrons to flow! This make your circuit a closed or complete circuit. When the drawings are apart, your circuit is open and no longer allowing electrons to flow through the loop.
Create a Maintained Switch with Binder Clips!
You can make a simple maintained switch by clipping EARTH to one binder clip and SPACE to another. When the two binder clips touch, the circuit is closed and complete! When you separate the binder clips, the circuit is open once again.
Get more cool ideas like this from Scrappy Circuits! You can use these same switches to light up LEDS. Plus, the folks at Scrappy Circuits have even more cool ideas for building switches out of scrappy everyday stuff!
|Create a Push Button Switch with a Paperclip!
A paper clip switch is similar to the drawn switch you made above, but acts more like a keyboard key. Put two brass fasteners through a small piece of cardboard. Place a paper clip on one fastener, and bend it so it doesn't touch the other fastener. Clip SPACE to paper clip fastener and EARTH to the other. When you press the paper clip to the second fastener, you close the loop and complete the circuit. This switch most resembles a keyboard key or a morse code machine!
|Create a Stomping Switch with Foil and Cardboard!
You can even make a pressure sensitive switch with cardboard and foil. You can use multiple rubber bands as the insulator between the two conductive pads and this will allow you to adjust the pressure needed to close the circuit. If you want an even sturdier stomping switch, see this guide.
What kind of games and projects will you design to accompany these switch inventions?
Check out this project example from Sam Yancey!