Confused by oscilloscope - square wave signal to RPM

[6v6gt]

@dovvvvv

noInterrupts();
  if (millis() >= millisLeds + 50)
  {
    if (dimmer = LOW){
     leds(); }
    else {
     ledsDimmed(); }  
     millisLeds = millis();
  }
  interrupts();

You are doing quite a lot with interrupts being suspended. This cannot be correct.