blinkfade.ino

#include<FastLED.h>

#define NUM_LEDS 178
CRGB leds[NUM_LEDS];

void setup() { 
  FastLED.addLeds<WS2811,7,GRB>(leds, NUM_LEDS);
  // do the initial setup of leds
  fill_solid(leds, NUM_LEDS, CRGB(32,0,32));
}

void loop() { 
  // fade any currently high leds
  for(int i = 0; i < NUM_LEDS; i++) { 
    if(leds[i].r > 32) { leds[i].r--; }
    if(leds[i].b > 32) { leds[i].b--; }
  }
  
  // pick a random led and make it high
  int nPicked = random16() % NUM_LEDS;
  leds[nPicked] = CRGB(64,0,64);
 
  // show the leds
  FastLED.show();

  // delay for a little bit - this means it'll take roughly 1 second for leds to fade from (64,0,64) back to (32,0,32)
  delay(30);
}