arduino LED + RFID

#include <Adafruit_NeoPixel.h>
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <NfcAdapter.h>

#define LED_RING_PIN D2
#define NUMPIXELS 16

Adafruit_NeoPixel pixels(NUMPIXELS, LED_RING_PIN, NEO_GRB + NEO_KHZ800);
PN532_I2C pn532i2c(Wire);
PN532 nfc(pn532i2c);

uint32_t greenColor = pixels.Color(0, 255, 0);
uint32_t color1 = pixels.Color(255, 69, 0);
uint32_t color2 = pixels.Color(75, 0, 130);
uint32_t color3 = pixels.Color(0, 255, 255);

const int MIN_BRIGHTNESS = 5;
const float MAX_BRIGHTNESS_SCALE = 0.8;
const int pixelMapping[NUMPIXELS] = {0, 1, 2, 3, 4, 5, 6, 7, 15, 14, 13, 12, 11, 10, 9, 8};

int flashCount = 3;
int ledPin = 13;
unsigned long lastAnimationTime = 0;
const int animationInterval = 20;

bool cardDetected = false;
unsigned long cardCheckTime = 0;
unsigned long cardDetectedTime = 0;
const int blinkDuration = 500;
int blinkCount = 0;
bool blinkState = false;

void setup() {
  Serial.begin(115200);
  pixels.begin();

  nfc.begin();
  if (!nfc.getFirmwareVersion()) {
    Serial.println("Didn't find PN53x board");
    while (1);
  }

  Serial.println("Waiting for an ISO14443A card");
  nfc.SAMConfig();

  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
}

void loop() {
  unsigned long currentTime = millis();

  if (!cardDetected && currentTime - cardCheckTime > (800 - random(100, 400))) {
    // Serial.println("Checking .......");
    checkRFID();
    cardCheckTime = currentTime;
  }

  if (cardDetected) {
    // Serial.println("handle");
    handleCardDetected(currentTime);
  }

  // Serial.println("done...");

  if (!cardDetected && currentTime - lastAnimationTime >= animationInterval) {
    // Serial.print("x");
    runGradientAnimation();
    lastAnimationTime = currentTime;
  }
}

void checkRFID() {
  uint8_t uid[7];
  uint8_t uidLength;

  if (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength, 1)) {
    Serial.println("Found a card!");
    Serial.print("UID Length: "); Serial.print(uidLength, DEC); Serial.println(" bytes");
    Serial.print("UID Value: ");
    for (uint8_t i = 0; i < uidLength; i++) {
      Serial.print(" 0x"); Serial.print(uid[i], HEX);
    }
    Serial.println("");

    cardDetected = true;
    cardDetectedTime = millis();
    blinkCount = 0;
    blinkState = true;
    setRingColor(greenColor);
  }
}

void handleCardDetected(unsigned long currentTime) {
  if (currentTime - cardDetectedTime >= blinkDuration) {
    cardDetectedTime = currentTime;
    blinkState = !blinkState;
    if (blinkState) {
      setRingColor(greenColor);
    } else {
      setRingColor(0);
      blinkCount++;
    }

    if (blinkCount >= flashCount) {
      Serial.println("reset");
      cardDetected = false;
      delay(500);
    }
  }
}

void setRingColor(uint32_t color) {
  for (int i = 0; i < NUMPIXELS; i++) {
    pixels.setPixelColor(i, color);
  }
  pixels.show();
}

void runGradientAnimation() {
  const int cycleTime = 3000;
  unsigned long currentTime = millis();
  float wavePosition = (currentTime % cycleTime) / (float)cycleTime;

  for (int i = 0; i < NUMPIXELS; i++) {
    float pixelFraction = (float)pixelMapping[i] / (NUMPIXELS - 1);
    uint32_t color;

    if (pixelFraction < 0.5) {
      color = interpolateColor(color1, color2, pixelFraction * 2);
    } else {
      color = interpolateColor(color2, color3, (pixelFraction - 0.5) * 2);
    }

    float angle = 2.0 * PI * (wavePosition + (float)i / NUMPIXELS);
    float brightnessFraction = (sin(angle) + 1) / 2;
    brightnessFraction = pow(brightnessFraction, 2.5);
    float brightness = brightnessFraction * MAX_BRIGHTNESS_SCALE;
    brightness = MIN_BRIGHTNESS / 255.0 + brightness * (1.0 - MIN_BRIGHTNESS / 255.0);

    uint32_t adjustedColor = adjustBrightness(color, brightness);
    pixels.setPixelColor(i, adjustedColor);
  }
  pixels.show();
}

uint32_t interpolateColor(uint32_t color1, uint32_t color2, float fraction) {
  uint8_t r = ((color1 >> 16) & 0xFF) + fraction * (((color2 >> 16) & 0xFF) - ((color1 >> 16) & 0xFF));
  uint8_t g = ((color1 >> 8) & 0xFF) + fraction * (((color2 >> 8) & 0xFF) - ((color1 >> 8) & 0xFF));
  uint8_t b = (color1 & 0xFF) + fraction * ((color2 & 0xFF) - (color1 & 0xFF));
  return pixels.Color(r, g, b);
}

uint32_t adjustBrightness(uint32_t color, float brightnessFactor) {
  uint8_t r = ((color >> 16) & 0xFF) * brightnessFactor;
  uint8_t g = ((color >> 8) & 0xFF) * brightnessFactor;
  uint8_t b = (color & 0xFF) * brightnessFactor;
  return pixels.Color(r, g, b);
}