====== Leds ======
  * [[https://youtu.be/Lr8P-FQSVrU|Intro about leds]]
  * [[https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/|Ledstrip examples]]
  * [[https://www.norwegiancreations.com/2018/01/programming-digital-rgb-led-strips-with-arduino-and-the-fastled-library/|Programming Digital RGB LED Strips with Arduino and the FastLED Library]]