I made a mask for Halloween. This mask has LED's eye and its mouth flashes red. This mask drops children there in fear.

Parts

Horror Mask
Tape LED Neopixel
Arduino Pro Mini 5V 16MHz
Electret Microphone Board
Red LED

Step 1: Step1: Paint the Mask Black

I bought a mask and painted black with a spray.

Step 2: Step2: LED Tape Processing

In order to paint the LED tape black, attach a masking tape to the light emitting part. I paint the LED black with a spray.

Attach the LED tape to the mask and wire it.

There are 68 LED cells. It is connected by one signal line.

Step 3: Step3: Microphone Attachment

Attach the Electret Microphone Board and two red LEDs to the mouth of the back of the mask.

The red LEDs glow in response to the voice.

Step 4: Step4: Overall Structure

Microcontroller (Arduino Pro Mini 5V 16MHz) controls LED tape, Electret Microphone Board, red LED.

Step 5: Step5: Code

LED Eye moves to the right or left and blinks randomly. The Electret Microphone Board detects the voice and lights the red LED.

#include <Adafruit_Neopixel.h>

const int analogInPin = A0;
const int ledPin = 12;

int sensorValue = 0;
int sensorTh = 700;
int avTime = 10;

#define PIN A3
Adafruit_NeoPixel led = Adafruit_NeoPixel(68, PIN, NEO_GRBW + NEO_KHZ800);

int blackNum = 24;
int pupilNum = 12;

uint32_t color;
int brightness = 20;
byte eyeColor;

int LR =7;

//Black eye L&R animation
int blackLED[15][24] = {{12,32,35,55,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        {12,13,31,36,54,55,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        {11,13,14,30,37,53,54,56,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        {10,11,14,15,29,38,52,53,56,57,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        { 9,10,11,12,15,16,28,33,34,39,51,52,55,56,57,58,68,68,68,68,68,68,68,68},
                        { 0, 8, 9,10,11,12,13,16,17,27,32,35,40,50,51,54,55,56,57,58,59,67,68,68},
                        { 0, 1, 7, 8, 9,10,13,14,17,18,26,31,36,41,49,50,53,54,57,58,59,60,66,67},
                        { 1, 2, 6, 7, 8, 9,14,15,18,19,25,30,37,42,48,49,52,53,58,59,60,61,65,66},
                        { 2, 3, 5, 6, 7, 8,15,16,19,20,24,29,38,43,47,48,51,52,59,60,61,62,64,65},
                        { 3, 4, 5, 6, 7,16,17,20,21,23,28,39,44,46,47,50,51,60,61,62,63,64,68,68},
                        { 4, 5, 6,17,18,21,22,27,40,45,46,49,50,61,62,63,68,68,68,68,68,68,68,68},
                       { 4, 5,18,19,26,41,48,49,62,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        { 4,19,20,25,42,47,48,63,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        {20,21,24,43,46,47,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68},
                        {21,23,44,46,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68,68}};

//pupil L&R animation
int pupilLED[15][12] = {{33,34,68,68,68,68,68,68,68,68,68,68},
                        {32,33,34,35,68,68,68,68,68,68,68,68},
                        {12,31,32,33,34,35,36,55,68,68,68,68},
                        {12,13,30,31,32,33,34,35,36,37,54,55},
                        {13,14,29,30,31,32,35,36,37,38,53,54},
                        {14,15,28,29,30,31,36,37,38,39,52,53},
                        {15,16,27,28,29,30,37,38,39,40,51,52},
                        {16,17,26,27,28,29,38,39,40,41,50,51},
                        {17,18,25,26,27,28,39,40,41,42,49,50},
                        {18,19,24,25,26,27,40,41,42,43,48,49},
                        {19,20,23,24,25,26,41,42,43,44,47,48},
                        {20,21,22,23,24,25,42,43,44,45,46,47},
                        {21,22,23,24,43,44,45,46,68,68,68,68},
                        {22,23,44,45,68,68,68,68,68,68,68,68},
                        {22,45,68,68,68,68,68,68,68,68,68,68}};

//Blink animation
int eyelid = 0;
int eyelidNum[8] = {0,4,8,16,24,34,44,56};
int eyelidLED[56] = {64,65,66,67,58,59,60,61,56,57,62,63,49,50,51,52,47,48,53,54,38,39,40,41,46,55,36,37,42,43,26,27,28,29,35,44,24,25,30,31,15,16,17,18,34,45,23,32,13,14,19,20,6,7,8,9};

void blink(int eyelid, int LR) {
  if (eyelid != 8){
    //White eye
    for(uint16_t i=0; i<led.numpixels(); i++) {
      led.setPixelColor(i, led.Color(0, 0, 0, 46));
      led.setPixelColor(11, led.Color(26, 26, 26));
    }

    //Black eye
    for(uint16_t i=0; i<blacknum; i++){
      led.setPixelColor(blackLED[LR][i], color);
    }

    //pupil
    for(uint16_t i=0; i<pupilnum; i++){
      led.setPixelColor(pupilLED[LR][i], led.Color(0, 0, 66));
    }

    //eyelid
    for(int i=0; i < eyelidNum[eyelid]; i++) {
      led.setPixelColor(eyelidLED[i], 0);
    }
  } else if (eyelid == 8){
    led.clear();
  }
  led.show();
}

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

  pinMode(ledPin, OUTPUT);

  led.begin();
  led.setBrightness(brightness); // Initial Brightness 40
  led.show(); // Initialize all pixels to 'off'

  color = led.Color(0, 177, 55); //pupil color

  blink(eyelid, LR);
}

void loop() {
  //mic input　LED
  for(int i = 0; i < avTime; i++){
    sensorValue += analogRead(analogInPin);
  }

  sensorValue = sensorValue / avTime;
  Serial.println(sensorValue);

  if(sensorValue > sensorTh){
    digitalWrite(ledPin, HIGH);
  }else{
    digitalWrite(ledPin, LOW);
  }

  int eyeMotion = random(0, 1200);

  switch (eyeMotion) {
    //Right
    case 10: 
      for(int i = LR; i < 12; i++){
        if(sensorValue > sensorTh) break;
        blink(0, i);
        delay(random(10, 100));
        LR = i;
      }

      if(sensorValue > sensorTh) break;
      delay(random(100, 700));

      for(int i=LR; i>=7; i--){
        if(sensorValue > sensorTh) break;
        blink(0, i);
        delay(random(10, 100));
        LR = i;
      }
      break;

    //Left
    case 123: 
      for(int i=LR; i>2; i--){
        if(sensorValue > sensorTh) break;
        blink(0, i);
        delay(random(10, 100));
        LR = i;
      }

      if(sensorValue > sensorTh) break;
      delay(random(100, 700));

      for(int i=LR; i<=7; i++){
        if(sensorValue > sensorTh) break;
        blink(0, i);
        delay(random(10, 100));
        LR = i;
      }
      break;

    //Blink
    case 32: 
    case 300:
      for(int i = 1; i < 9; i++){
        if(sensorValue > sensorTh) break;
        blink(i, LR);
        delay(random(10, 30));
      }

      if(sensorValue > sensorTh) break;
      delay(random(10, 300));

      for(int i = 8; i > 0; i--){
        if(sensorValue > sensorTh) break;
        blink(i, LR);
        delay(random(10, 30));
      }
      break;

    default:
      blink(0, 7);
  }

  sensorValue = 0;
}