Arduino Starter Kit - Project 7 - Keyboard Instrument

Resistor ladder

This is a way to read a number of switches using the analog input. It’s a helpful
technique if you find yourself short on digital inputs. You’ll hook up a number of
switches that are connected in parallel to analog in 0. Most of these will connect
to power through a resistor. When you press each button, a different voltage level
will pass to the input pin.

• Arduino resistor ladder video
• Instructables tutorial

Building

I had a lot of trouble relating the breadboard layout to the schematic, evidence of my being a novice. I spent a lot of time trying to understand it.