I am building a hard drive POV clock. (google it, they are pretty cool) I am working on the code for it, right now all i want to do is get the hang of making it do simple patterns with the RGB leds. I am wondering if anyone has any ideas on how to do something simple like make a red line rotate around the platter. right now what i have is an interrupt that triggers a function. int gLED = 8; // pins for RGB led strip int rLED = 9; int bLED = 10; attachInterrupt(0, ledPattern, FALLING); void ledPattern(){ digitalWrite(gLED, HIGH); // This will make a stable image of slice of the delayMicroseconds(500); // platter, but it does not move. digitalWrite(gLED, LOW); } That is the main part of the code (obviously I cut some stuff out that arduino requires) What I am trying to figure out is how can make that slice rotate around the platter. Eventually I will make the pattern more interesting by adding in other colors. Any Ideas?