Use an IR LED connected to an Arduino as a remote controller for LED light strip, to behave as a DIY wake-up light alarm clock. Useful when your country is way up north (or south) and the sun doesn't come up until late in winter. Goes through a preset sequence of colors simulating sunset and sunrise.
I use an Intertronic RGB LED Strip, but I suspect the underlying protocol is the same for many other similar IR remote-controlled LEDs.
connect LED strip to power, connect IR LED (with appropriate resistor) to pin 3.
https://www.instructables.com/BruteForce-Codefinding-for-Infrared-RGB-LEDstrip/
Then Arduino said.... "let there be light!"