Playing with multiple buttons
We can extrapolate our previously designed logic with more than one switch.
There are many ways to use multiple switches, and, in general, multiple inputs on the Arduino. We're going to see a cheap and easy first way right now. This way doesn't involve multiplexing a lot of inputs on only a couple of Arduino inputs but a basic one to one wiring where each switch is wired to one input. We'll learn multiplexing a bit later (in the next chapter).
The circuit
Following is the circuit diagram required to work with multiple switches:
The schematic is an extrapolation of the previous one that showed only one switch. We can see the three switches between the +5 V and the three pull-down resistors. Then we can also see the three wires going to digital inputs 2 to 4 again.
Here is a small memory refresh: Why didn't I use the digital pins 0 or 1?
Because I'm using serial communication from the Arduino, we cannot use the digital...