Button multiplexing
Using a multiplexer, it is possible to make the Arduino read over a hundred buttons easily. A multiplexer/demultiplexer is an integrated circuit that selects one of several inputs and forwards them to the output. It requires a few control pins to determine which input to forward to the output.
Getting ready
Following are the ingredients required for this recipe:
An Arduino board connected to a computer via USB
A breadboard and jumper wires
Four buttons
A 4051 multiplexer or similar, which we can find at any electronics store and online at Digikey, Sparkfun, Adafruit, and so on
How to do it…
We implement a simple configuration using only four buttons. Here are the steps:
Connect the Arduino GND to a long strip on the breadboard. Also connect the Arduino 5V to a long strip.
Mount the four buttons and connect one of their terminals to the long GND strip.
Connect the other terminal of each button to an individual input/output pin on the 4051—in this case, pins y0, y1, y2, and y3.
Connect...
