#include <Adafruit_NeoPixel.h>

#define LED_PIN 4
#define RING_SIZE 16

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(RING_SIZE, LED_PIN, NEO_GRB + NEO_KHZ800);

void run_ring(uint8_t red, uint8_t green, uint8_t blue, uint16_t interval);

void setup() {
  pixels.begin();
  Serial.begin(115200);
  Serial.println("Starting semaphore v3");
}

void loop() {
  run_ring(255, 0, 0, 1000);
  run_ring(0, 255, 0, 500);
  run_ring(255, 255, 0, 250);
}

void run_ring(uint8_t red, uint8_t green, uint8_t blue, uint16_t interval) {
  for (uint8_t i = 0; i < RING_SIZE; i++) {
    pixels.setPixelColor(i, red, green, blue);
  }
  pixels.show();
  delay(interval);
  for (uint8_t i = 0; i < RING_SIZE - 1; i++) {
    pixels.setPixelColor(i, 0, 0, 0);
    pixels.show();
    delay(interval);
  }
  pixels.clear();
  pixels.show();
}