Did you know that you can use Arduino to turn on an LED when you press a button? Well, it is true, you can do this! Leaving the joke aside, let me show how you can achieve this. You will need the ...

so tinkercad has circuit designand arduno now, a real arduino is $20, IDE is free, fritzing is free and does all the exact same layout stuff locally, you save your files and keep them forever.

When the Arduino code sees the button getting pressed, it brings the corresponding LED pin high and starts a fade out timer using the SoftPWM library by [Brett Hagman].