Published August 29, 2020 © GPL3+

Touchless Thermometer

This project can measure human body temperature without contact, and it also can send an alarm when it has detected an unnormal temperature.

IntermediateFull instructions provided8,745

Things used in this project

Hardware components

Arduino Nano R3

5 mm LED: Red

5 mm LED: Yellow

5 mm LED: Green

Ultrasonic Sensor - HC-SR04 (Generic)

Buzzer

Rotary Encoder with Push-Button

Resistor 10k ohm

Resistor 1k ohm

Jumper wires (generic)

Custom PCB

MLX90641

Adafruit Standard LCD - 16x2 White on Blue

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Story

How does the machine work?

INTRODUCTION:

I decided to build a low-cost thermometer that can measure human body temperature without contact when I knew that people should avoid unnecessary connection and remain at a social distance with others to prevent the infection of coronavirus.

SOFTWARE:

Arduino IDE

MAIN HARDWARE:

LED:

LED lights will glow red, when the machine has measured a temperature that is higher than or equal to the value of the alarming temperature.

LED lights will glow green, when the machine has measured a temperature that is lower than the alarming temperature.

Buttons:

Adjust the value of the alarming temperature.

LCD screen:

Display the measured temperature and the alarming temperature respectively.

Arduino Nano:

Instruct sensors, LED and button.

Thermal sensor MLX90641:

Measure temperature.

Ultrasonic distance measurement sensor:

The ultrasonic sensor locates at the front of the machine and the sensor can measure the distance between the device and the person. And this machine only starts measuring the body temperature when the distance between the person and the machine is within a certain fixed value.

WORKING PROCESS:

The CPU instructs the thermal sensor and the ultrasonic sensor to work together to measure the temperature of a object.
When the machine has measured a temperature that is higher than or equal to the value of the alarming temperature, the Arduino Nano would instruct the LED lights to glow red and the buzzer to beep urgently. And when the machine has measured a temperature that is lower than the alarming temperature, the LED lights glow green, the buzzer beeps once.
The LCD screen locates at the back of the machine, thus users can read the measured body temperature via the LCD screen easily, in addition, the LCD can display both the alarming temperature and the measured temperature at the same time.
Users can adjust the value of the alarming temperature by pressing the buttons of the machine.

The LED glows red when the measured temperature is higher than the alarming temperature.

The LED glows green when the measured temperature is lower than the alarming temperature.

Code

MLX90641_Buzzer Code

/*  Written by HuiQiao  
 */
 
 
 #include <EEPROM.h>
#include <Wire.h>
#include <LiquidCrystal.h>
#include <Adafruit_MLX90614.h>
#include "Adafruit_NeoPixel.h"
#ifdef __AVR__
#include <avr/power.h>
#endif




LiquidCrystal lcd(6, 10, 9, 14, 15, 16);




#define RGBPIN            4
#define NUMPIXELS         4
#define btnRIGHT  0
#define btnUP     1
#define btnDOWN   2
#define btnLEFT   3
#define btnSELECT 4
#define btnSELECT1 6
#define btnNONE   5
#define BellStart 5
#define CLOSEDIS  40
Adafruit_MLX90614 mlx = Adafruit_MLX90614();




int musicpin=5;
int bellFlag=0;
int soundFlag=1;
int startFlag=0;
int TrigPin = 1; 
int EchoPin = 0; 




Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, RGBPIN, NEO_GRB + NEO_KHZ800);
byte bell[8] =
{
 B00010,
 B00111,
 B00111,
 B00110,
 B00111,
 B10110,
 B11110,
 B01010
};
byte bell1[8] =
{
 B00001,
 B00011,
 B00100,
 B01000,
 B01000,
 B01000,
 B11111,
 B00001
};

byte bell2[8] =
{
 B10000,
 B11000,
 B00100,
 B00010,
 B00010,
 B00010,
 B11111,
 B10000
};
byte bell3[8] =
{
 B00001,
 B00010,
 B00100,
 B01000,
 B10000,
 B11000,
 B00111,
 B00000
};
byte bell4[8] =
{
 B00001,
 B00010,
 B00100,
 B01000,
 B10000,
 B11000,
 B00111,
 B00000
};
byte bell5[8] =
{
 B00000,
 B00011,
 B00111,
 B11101,
 B11101,
 B00111,
 B00011,
 B00000
};
byte bell6[8] =
{
 B00001,
 B00010,
 B00100,
 B01000,
 B10000,
 B11000,
 B00111,
 B00000
};
byte freep[8] =
{
 B00000,
 B00000,
 B00000,
 B00000,
 B00000,
 B00000,
 B00000,
 B00000
};




int mat1=0;
int mat2=0;
/////////////////////////////////////////
struct bellTime{
    int thour;
    int tmin;
    int tsec;
};
bellTime _bTime;
bellTime _obTime;

int wb_H=0;
int wb_L=30;
/////////////////////////////////////////
void setup() {
  
  int i;
  
  float wTemp;
  
  Serial.begin(9600);
  
  pinMode (musicpin, OUTPUT);
  
  pinMode (A0, INPUT);
  
  pinMode (A1, INPUT);
  
  pinMode (A2, INPUT);
  
  pinMode (A3, INPUT);
  
  pinMode (7, INPUT);
  
  pinMode (8, INPUT);
  
  pinMode(TrigPin, OUTPUT);
  
  pinMode(EchoPin, INPUT); 
  
  mlx.begin();
  
  delay(100);
  
  for(i=0;i<8;i++)
  
  {
    
    bell3[i] = ~bell1[i];
    
    bell4[i] = ~bell2[i];
    
    bell6[i] = ~bell5[i];
    
    }  
    
  lcd.createChar(0, bell);
  
  lcd.createChar(1, bell1);
  
  lcd.createChar(2, bell2);
  
  lcd.createChar(3, bell3);
  
  lcd.createChar(4, bell4);
  
  lcd.createChar(5, bell5); 
  
  lcd.createChar(6, bell6);
  
  lcd.begin(16, 2);
  
  ////////////////////////////////////
  
  wb_H = ReadCfg(0); 
  
  wb_L = ReadCfg(1);
  
  wTemp = ((wb_H<<8)+wb_L)/10.0;  
  
  ////////////////////////////////////
  
  char tmbuff[16];
  
  mat1 = 1;
  
  lcd.setCursor(BellStart-3,1);
  
  lcd.write(mat1);
  
  mat2 = 2;
  
  lcd.setCursor(BellStart-2,1);
  
  lcd.write(mat2);
  
  mat1 = 6;
  
  lcd.setCursor(12,1);
  
  lcd.write(mat1);

  dtostrf(wTemp,2,1,tmbuff);
  
  String s = String(tmbuff)+"*C";
  
   lcd.setCursor(BellStart,1);
   
   lcd.print(s);
   
  pixels.begin(); 

}

int frmCnt=0;
int crosPos=0;


void loop() {
  
    int frameDelay=25;
    
    float boTemp;
    
    float sum;
    
    char tmbuff[2];
    
    char disbuff[16];
    
    String s;   
    
    char sHour[4];
    
    char sMin[4];
    
    char sSec[4]; 
    
    int i;
    
    float distance;
    
    
    
    
    // 10usTrigPin 
    
        digitalWrite(TrigPin, LOW); 
        
        delayMicroseconds(2); 
        
        digitalWrite(TrigPin, HIGH); 
        
        delayMicroseconds(10);
        
        digitalWrite(TrigPin, LOW); 
        
    // 
    
    
        distance = pulseIn(EchoPin, HIGH) / 58.00;
        
        Serial.print(distance); 
        
        Serial.print("cm"); 
        
        Serial.println(); 
        
        if(distance<10||distance>CLOSEDIS)
        
        {
          
          for( i=0;i<NUMPIXELS;i++){ 
            
            pixels.setPixelColor(i, pixels.Color(0,0,0));
            
            pixels.show(); 
            
            }
            
            startFlag=0;
            
          delay(1000);
          
          return;
          
          }else if(distance<CLOSEDIS)
          
          {
            
            for( i=0;i<NUMPIXELS;i++){ 
              
            pixels.setPixelColor(i, pixels.Color(200,255,0));
            
            pixels.show(); 
            
            }
            
            startFlag = 1;
            
            }
    
      if(getKey()==btnSELECT)
      
      {
        SetClock();
        
        }else if(getKey()==btnLEFT)
        
        {
          soundFlag = 1;
          
          mat1 = 5;
          
          lcd.setCursor(12,1);
          
          lcd.write(mat1);
          
          }else if(getKey()==btnRIGHT)
          
        {
          soundFlag = 0;
          
          mat1 = 6;
          
          lcd.setCursor(12,1);
          
          lcd.write(mat1);
          
          }
             
      if(startFlag)
      
      {
        sum=0.0;
        
        if(startFlag==1)
        
        {
          s = "|";
          
          for(i=0;i<5;i++)
          
          {
            s+="-";
            
            sum+=mlx.readObjectTempC();
            
            delay(200);
            
            lcd.setCursor(5,0);
            
            lcd.print(s);
            
            }

            sum = sum/5.0;
            
            dtostrf(sum,2,1,disbuff);
            
    s = String(disbuff)+"*C;
    
    lcd.setCursor(5,0);
    
    lcd.print(s);
    
    if((sum*10)>((wb_H<<8)+wb_L))
    
    {
      for( i=0;i<NUMPIXELS;i++){ 
        
            pixels.setPixelColor(i, pixels.Color(255,0,0));
            
            pixels.show(); 
            
            }
      Warnning(18);
      
      }else{
        
        for( i=0;i<NUMPIXELS;i++){ 
          
            pixels.setPixelColor(i, pixels.Color(0,255,0));
            
            pixels.show();
            
            }
            
        Warnning(2);
        
        }
    
          }
          
          startFlag++;
          
          if(startFlag==10)
          
              startFlag=0;
        }
        
   delay(500);
  
}
void Warnning(int b)
{
  int i;
  
  for(i=0;i<b;i++)
  
  {
    if((i%2)==0)
    {
      mat1 = 3;   
      
      mat2 = 4;  
      
      }else{
        
      mat1 = 1;   
      
      mat2 = 2;  
        }
        
       lcd.setCursor(BellStart-3,1);
       
       lcd.write(mat1); 
       
       lcd.setCursor(BellStart-2,1);
       
       lcd.write(mat2); 
       
       if(soundFlag) 
       
       {
         
        digitalWrite(musicpin,(i%2));    
        
          }
          
       delay(1000/b);
    }
    
    digitalWrite(musicpin,0); 
    
  }
//



void SetClock(){
  
  int setCnt=0;
  
  char tmbuff[16];
  
  String s;
  
  int noact=0;
  
  int aimDis = ((wb_H<<8)+wb_L);
  
  float setVal;
  
    crosPos = 1;
    
        setCnt = 0;
        
        lcd.setCursor(BellStart+crosPos+2,1);
        
        lcd.blink();
        
        for(;;)
        
        {             
             if(setCnt>3&&getKey()==btnSELECT1)
             
             {     
                 break;
              }   
              
             if(getKey()==btnUP)
             
              {
                noact=0;
                
                lcd.noBlink();
                
                      if(aimDis<400)
                      
                      aimDis++;
                      
                      else
                      
                      aimDis=0;
                      
                      setVal = aimDis/10.0;
                      
                      dtostrf(setVal,2,1,tmbuff);
                      
                      s = String(tmbuff)+"*C";
                      
                      lcd.setCursor(BellStart+crosPos-1,1); 
                      
                      lcd.print(s);  
                      
                      lcd.setCursor(BellStart+crosPos+2,1);    
                      
                      lcd.blink();
                      
                }else if(getKey()==btnDOWN)
                
              {
                noact=0;
                
                lcd.noBlink();
                
                      if(aimDis>0)
                      
                      aimDis--;
                      
                      else
                      
                      aimDis=400;
                      
                      setVal = aimDis/10.0;
                      
                      dtostrf(setVal,2,1,tmbuff);
                      
                      s = String(tmbuff)+"*C";
                      
                      lcd.setCursor(BellStart+crosPos-1,1);  
                      
                      lcd.print(s);
                      
                      lcd.setCursor(BellStart+crosPos+2,1);                      
                      lcd.blink();
                      
                }else if(getKey()==btnNONE)
                
                {
                  noact++;
                  
                  if(noact>50)
                  
                  break;
                  
                  }
                  
              delay(200);
              
              setCnt++;
              
          }
          
          //RTC.begin();
          
          crosPos = 0;
          
          lcd.noBlink();
          
          wb_H = aimDis>>8;
          
          wb_L = aimDis&0xff;
          
          WriteCfg(0,wb_H);
          
          WriteCfg(1,wb_L);
          
          Serial.println("set ok!");

}

int getKey() {
  
   if(!digitalRead(A0))
   
   {
    delay(10);
    
    if(!digitalRead(A0))
    
       return btnUP;
       
    }
   if(!digitalRead(A1))
   
   {
    delay(10);
    
    if(!digitalRead(A1))
    
    return btnRIGHT; 
    
    }
   if(!digitalRead(A3)){ 
     
    delay(10);
    
    if(!digitalRead(A3))
    
    return btnDOWN;
    
    }
   if(!digitalRead(A2)){
     
    delay(10);
    
    if(!digitalRead(A2))
    
     return btnLEFT;
     
     }
   if(!digitalRead(7)) {
     
    delay(10);
    
    if(!digitalRead(7))
    
    return btnSELECT;
    
    } 
    if(!digitalRead(8)) {
      
    delay(10);
    
    if(!digitalRead(8))
    
    return btnSELECT1; 
    
    } 
  return btnNONE;
  
}

unsigned char ReadCfg(unsigned char addr)

 {
      unsigned char val;
      
      val =  EEPROM.read(addr);  
      
      return val;
      
  }
  
  void WriteCfg(unsigned char addr,unsigned char val)
 {
      EEPROM.write(addr, val);
  }

Credits

WU_HuiQiao

1 project • 8 followers

I like building things.

Touchless Thermometer

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

INTRODUCTION:

SOFTWARE:

MAIN HARDWARE:

WORKING PROCESS:

Schematics

Schematic for the project

Code

MLX90641_Buzzer Code

Credits

WU_HuiQiao

Comments

Embed the widget on your own site

Touchless Thermometer

Touchless Thermometer

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

INTRODUCTION:

SOFTWARE:

MAIN HARDWARE:

WORKING PROCESS:

Schematics

Schematic for the project

Code

MLX90641_Buzzer Code

Credits

WU_HuiQiao

Comments

Related channels and tags