This sample code is for Contact-Less Hand Washing LED Ring Timer Using Maker UNO tutorial.

LED_timer.ino

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h>
#endif

#define LED_RING    5
#define SENSOR      6
#define PIEZO       8
#define NUMPIXELS   12 // NeoPixel ring size

Adafruit_NeoPixel pixels(NUMPIXELS, LED_RING, NEO_GRB + NEO_KHZ800);

#define NOTE_B5  988
int startNoteDurations[] = {8,4,4};

int stopMelody[] = {NOTE_B5};
int stopNoteDurations[] = {8};

#define playstopMelody() playMelody(stopMelody, stopNoteDurations, 2)

char inChar;
String inString;

void setup() {

#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif

  pinMode(SENSOR, INPUT);
  pinMode(PIEZO, OUTPUT);
  pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)
  Serial.begin(9600);
}

void loop() {
  pixels.clear(); // Set all pixel colors to 'off'
  pixels.show();   // Send the updated pixel colors to the hardware.

  if (digitalRead(SENSOR) == HIGH) {

    for (int i = NUMPIXELS; i >= 0; i--) {
      pixels.setPixelColor(i, pixels.Color(100, 5, 5));
      pixels.show();
      delay(250); // Pause before next pass through loop
    }

    for (int i = 0; i < NUMPIXELS; i++) {
      Serial.print("i = ");
      Serial.println(i);
      pixels.setPixelColor(i, pixels.Color(10, 100, 10));
      pixels.show();
      delay(1700);
    }
    blinking(3);
  }
  else {
    pixels.clear();
    pixels.show();
  }
}

void blinking(int times)
{
  for (int i = 0; i < times; i++) {
    pixels.clear();
    pixels.show();
    delay(200);
    for (int i = 0; i < 12; i++) {
      pixels.setPixelColor(i, pixels.Color(5, 100, 5));
      pixels.show();
    }
    delay(200);
    playstopMelody();
  }
  
}

void playMelody(int *melody, int *noteDurations, int notesLength)
{
  for (int thisNote = 0; thisNote < notesLength; thisNote++) {
    int noteDuration = 1000 / noteDurations[thisNote];
    tone(PIEZO, melody[thisNote], noteDuration);
    int pauseBetweenNotes = noteDuration * 1.30;
    delay(pauseBetweenNotes);
    noTone(PIEZO);
  }
}