Using Melexis None-Contact MLX90614 Infrared Thermometer wiht ESP32 over Bluetooth

Project Video
Project Details

In this tutorial you will learn how to display temperature on mobile phone over Bluetooth using ESP32 Arduino board with MLX90614
infrared none-contact temperature sensor.

Chapters of this video

  • 00:45 Introduction
  • 04:20 Wiring Explained
  • 05:37 Code is explained
  • 06:49 Demonstration

Project Code


//*
 * 
 * 
 * This is Arduino code to Measure Temperature over Bluetooth using
 MLX90614 with ESP32
 
 * Watch video instruction for this code: https://youtu.be/HpsvNIAtjm4
   
 * Written/updated by Ahmad Shamshiri for Robojax Video channel www.Robojax.com
 * Date: July 01, 2020, in Ajax, Ontario, Canada

 Related Videos:
 Related videos: 
Introduction to MLX90614 Non-Contact https://youtu.be/cFDSqiEIunw
Display Temperature on LCD from MLX90614: https://youtu.be/_iO2L4P_irw
Measure temperature using MLX90614 Over WiFi:
 
 * this code has been downloaded from http://robojax.com/learn/arduino/
 
 * Get this code and other Arduino codes from Robojax.com
Learn Arduino step by step in structured course with all material, wiring diagram and library
all in once place. Purchase My course on Udemy.com http://robojax.com/L/?id=62

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videos I publish on YouTube here: http://robojax.com/L/?id=63 (watch until end of this video to list of my Patrons)
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or make donation using PayPal http://robojax.com/L/?id=64

 *  * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see .
 */

#include 
#include 
char *typeName[]={"Object: ","Ambient: "};
float tempC, tempF, tempK, tempCA, tempFA, tempKA;
int type=1;// 1=C, 2=F, 3=K,
int showAmbient =1;//1=yes, 0=no

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

#include "BluetoothSerial.h"
#if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BLUEDROID_ENABLED)
#error Bluetooth is not enabled! Please run `make menuconfig` to and enable it
#endif

BluetoothSerial SerialBT;
int inData;

char receivedChar;// received value will be stored as CHAR in this variable

void setup() {
  Serial.begin(115200);
  SerialBT.begin("ESP32_Robojax"); //Bluetooth device name
  Serial.println("The device started, now you can pair it with bluetooth!");
  Serial.println("Search for ESP32_Robojax device and Pair your phone to ESP32_Robojax");  
  
     mlx.begin();  
	  //Robojax.com MLX90614 with ESP32 Bluetooth

}

void loop() {
   getTemp();
  //Robojax.com MLX90614 with ESP32 Bluetooth
  if (Serial.available()) {
   // SerialBT.write(Serial.read());
  
  }
  while (SerialBT.available() ) {
    receivedChar =(char)SerialBT.read();
    inData += receivedChar;    
        if (receivedChar == '\n')
        {    
   // SerialBT.print("Received:");// write on BT app
    //SerialBT.println(inData);// write on BT app   

    //Serial.print("Received:");//print on Serial Monitor
   // Serial.println(inData); //print on Serial Monitor     
    
    type = inData;
    sendTemp();
   
           inData = 0; // Clear recieved buffer                    
                  
        }//if (receivedChar


  }// while

        //Serial.println(servo1Angle);
        delay(20);
//Robojax.com MLX90614 with ESP32 Bluetooth
}//loop ends here

void sendTemp()
{

//Robojax.com MLX90614 with ESP32 Bluetooth
    if(type ==24)
    {
      SerialBT.print(typeName[0]);
      SerialBT.print(tempC);//object Temperature 
      SerialBT.println("°C");
      Serial.print("Temperature:"); //print on Serial Monitor    
      Serial.println(tempC); //print on Serial Monitor      
      if(showAmbient)
      {
        SerialBT.print(typeName[1]);
        SerialBT.print(tempCA);//ambient temperature 
        SerialBT.println("°C");        
      }
    }
    if(type ==25)
    {
      SerialBT.print(typeName[0]);
      SerialBT.print(tempF);//object Temperature 
      SerialBT.println("°F");
      if(showAmbient)
      {
        SerialBT.print(typeName[1]);
        SerialBT.print(tempFA);//ambient temperature 
        SerialBT.println("°F");        
      }
    }
    if(type ==26)
    {
      SerialBT.print(typeName[0]);
      SerialBT.print(tempC);//object Temperature 
      SerialBT.println("°K");
      if(showAmbient)
      {
        SerialBT.print(typeName[1]);
        SerialBT.print(tempKA);//ambient temperature 
        SerialBT.println("°K");        
      }
    } 
//Robojax.com MLX90614 with ESP32 Bluetooth	
}//sendTemp ends here



/*
 * @brief returns temperature or relative humidity

 * @return returns one of the values above
 * Usage: to get Fahrenheit type: getTemp('F')
 * to print it on serial monitor Serial.println(getTemp('F'));
 * Written by Ahmad Shamshiri on Mar 30, 2020. 
 * in Ajax, Ontario, Canada
 * www.Robojax.com 
 */
void getTemp()
{
   // Robojax.com MLX90614 Code

    tempC = mlx.readObjectTempC();//in C object
    tempCA = mlx.readAmbientTempC();

    tempF = mlx.readObjectTempF(); //Fah. Object
    tempFA = mlx.readAmbientTempF();//Fah Ambient

    tempK = tempC + 273.15;// Object Kelvin
    tempKA =  tempCA + 273.15;//Ambient Kelvin

    // Robojax.com MLX90614 Code
}//getTemp