I'm working on a project and I want to control a whole bunch of LEDs, but I don't have enough GPIO pins on my microcontroller. If you’ve been tinkering with electronics for any amount of time, you’ve probably run into this situation before. Maybe it wasn’t LEDs, but some other output like relays. Or maybe you were trying to read a ton of button inputs and you were short on GPIO pins. I'm going to show you how to solve this problem and potentially save your project by using a technique called multiplexing.

Bill of materials:
10mm RGB LED https://www.digikey.com/short/3vj2wjvv
Arduino Board https://www.digikey.com/short/70bf53w8
Breadboard https://www.digikey.com/short/nbh4q298
Resistor Kit https://www.digikey.com/short/q4w7wj75
Jumper Wire Kit https://www.digikey.com/short/8n0p92pn
Keypad 12 keys https://www.digikey.com/short/f51mmwwv
Keypad 16 keys https://www.digikey.com/short/zp50wmz3


7 segment LED board Github project
https://github.com/bytesizedengineeri...

Learn More:
Arduino page explaining direct port manipulation: https://docs.arduino.cc/hacking/softw...

DigiKey blog post diving further into the topic of direct port manipulation: https://www.digikey.com/en/blog/thec...