#include <FastLED.h>

#define NUM_STRIPS 2
#define NUM_LEDS_PER_STRIP 15
#define NUM_LEDS NUM_LEDS_PER_STRIP * NUM_STRIPS

CRGB leds[NUM_STRIPS * NUM_LEDS_PER_STRIP];
const unsigned long delayTime = 500;

// For mirroring strips, all the "special" stuff happens just in setup.  We
// just addLeds multiple times, once for each strip
void setup() {
  Serial.begin(115200);
  Serial.println("Setup-Start");

  // tell FastLED there's 15 NEOPIXEL leds on pin A0, starting at index 0 in the led array
  FastLED.addLeds<NEOPIXEL, A0>(leds, 0, NUM_LEDS_PER_STRIP);

  // tell FastLED there's 15 NEOPIXEL leds on pin A1, starting at index 15 in the led array
  FastLED.addLeds<NEOPIXEL, A1>(leds, NUM_LEDS_PER_STRIP, NUM_LEDS_PER_STRIP);

}

void printLEDNr(int IndexNr) {
  Serial.print("leds[");
  Serial.print(IndexNr);
  Serial.print("]= red");
  Serial.println();
}

void loop() {
  // count up from 0 to 14
  for (int i = 0; i < NUM_LEDS_PER_STRIP; i++) {
    leds[i] = CRGB::Red;
    printLEDNr(i);
    FastLED.show();
    leds[i] = CRGB::Black;
    delay(delayTime);
  }

  // count downwards from 29 to 15
  for (int i = NUM_LEDS - 1; i >= NUM_LEDS_PER_STRIP ; i--) {
    leds[i] = CRGB::Red;
    printLEDNr(i);
    FastLED.show();
    leds[i] = CRGB::Black;
    delay(delayTime);
  }

}