5. Install FastLED. You’ll need this program for your code to run—it’s, a library that takes some of the nitty-gritty work out of coding each LED to light up manually.

When you read “Arduino wristwatch”, you fall into the trap of envisioning an Arduino UNO clumsily strapped to someone’s wrist. [Marijo Blažević’s] creation is much more poli… ...