Connected Visor

#include <Wire.h>
#include <Adafruit_MLX90614.h> // adafruit library
#include <SoftwareSerial.h>

SoftwareSerial serieBT(10, 11); //RX TX define
Adafruit_MLX90614 mlx = Adafruit_MLX90614();

const int trigPin = 4;
const int echoPin = 3;
long duration;
int distance;
int a=0;

bool Handwash = true;
bool Sound = true;

char junk;
String inputString="";
char c;
String Data;
int i=0;

unsigned long intervall2 = millis(); 


void setup() 
{
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT); 
  pinMode(5, OUTPUT); 
  pinMode(6, OUTPUT); 
  Serial.begin(9600);
  mlx.begin();  
  serieBT.begin(9600); 
  }

void loop() {
  // the bluetooth is used to configure the visor throuth the mobile application
  if(serieBT.available()){
    while(serieBT.available())
    {
      char inChar = (char)serieBT.read(); //read the input 
      inputString += inChar;        //make a string of the characters coming on serial
      }
    while (serieBT.available() > 0)  
    {
      junk = serieBT.read();
      }

    // if message is 1a the visor desactive handwash function
    if(inputString == "1a\r\n"){
      Handwash = false;
      }
    // if message is 1b the visor active handwash function
    if(inputString == "1b\r\n"){
      Handwash = true;
      }
    // if message is a the visor active the piezo speaker in the social distance function
    if(inputString == "a\r\n"){
      Sound = true;
      }
    // if message is a the visor desactive the piezo speaker in the social distance function
    if(inputString == "b\r\n"){
      Sound = false;
      }
    inputString = "";
    }
 
   else{ 
    Serial.print("ok ");
    if(millis()>intervall2+10000){ 
        serieBT.print(mlx.readAmbientTempC()); //the temperature is send every 10 second to the application to displaying
        intervall2 = millis();
        }
    fdistance();
    delay(200);
    //the function who active handwash funtion if you placed 
    if(i >8){
        if (Handwash) hand();
        else i = 0; 
        }
       }
  }

// function distanciation social 1 meter
void fdistance(){
  digitalWrite(trigPin, LOW);delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance= duration/58.2;
  Serial.println(distance);
  delay(100);
  if(distance<=100){
    digitalWrite(5, HIGH);
    if(Sound){
      digitalWrite(6, HIGH);
      }
    if (distance <10){
      i++;
      }
    }
  else if(distance> 100){
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    }
}

//handwashing timer function (20 sec)
void hand (){
  unsigned long currentMillis = millis();
  unsigned long intervall = currentMillis + 20000; 
  i = 0;

  //the piezo speaker sound three time to warn user that he can start washing hand

  digitalWrite(6, LOW);
  delay(200);
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);
  delay(200);
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);
  delay(200);
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);

  //20 second timer
  while(millis()<intervall)
  {
    Serial.print("hand");
    digitalWrite(5, HIGH);
    }
    
   //the piezo speaker sound three time to warn user that he can stop washing hand
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);
  delay(200);
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);
  delay(200);
  digitalWrite(6, HIGH);
  delay(200);
  digitalWrite(6, LOW);
  }