How Does the Big Arduino Piano Work?

The video covers everything you need to know to make the keyboard and attach the pushbuttons, so I'll just stick to the technical details here. If you don't have enough pushbuttons, you can still follow along with just one pushbutton, some resistors, and a speaker.



If you've used an Arduino before, you've probably used a pushbutton and understand how important a pulldown resistor is. A pulldown resistor "holds the logic signal near zero volts when no other active device is connected", (Arduino Playground). This helps to ensure that we get reliable and accurate readings from our pushbuttons.



We have eight pushbuttons connected to pins 2-9. Each button requires 5V power, a 10k pulldown resistor, and a signal line to the input pins. Each of these buttons can be assigned a specific square-wave frequency to play whenever the button is pressed (logic HIGH) within our program. These are specific frequencies that help create musical scale.