Help with a script

Using Arduino LEDs and Multiplexing
6 
void FAST() {
for(int a =150;a>=10; a--){
FastLED.clear();                                                       
  set5leds2(index1);
  index1 = (index1 + 1) % (NUM_LEDS + 4);
  if (millis() - initialtime > 1000) {
   
  }

Count your { and } that bit of code makes no sense. It says if millis() - initialtime > 1000 then do nothing, otherwise do nothing.

then always do:-

set5leds2(index2);
    index2 = (index2 + 1) % (NUM_LEDS + 4);

and clear all the the LEDs each time round the for loop. So you end up with just that last operation at the end of the loop.

Place the cursor to the right of a { and click, the matching closing brace will be in a box so you can see your groups.

void Fastled ......... void Fast

They are called the Fastled function and the Fast function. Void is not part of the function's name, it just tells you what sort of variable it returns. Never speak of it again. :slight_smile: