Make your own Thermogun using arduino and mlx90614
arduino D.I.Y sensor

Make your own Thermogun using arduino and mlx90614

admin December 30, 2020

let’s start make our own thermogun. In this tutorial I will make thermogun using temperature sensor MLX90614 and arduino nano. Also OLED display to display the result.

Wiring Diagram

DIY thermogun, using arduino nano, OLED display and MLX90614

The Code

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_MLX90614.h>
#include <Fonts/FreeMonoBold18pt7b.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

void setup() {
  Serial.begin(9600);
  mlx.begin();

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
}

void loop() {
  printText();
  delay(500);
  display.clearDisplay();
}

void printText() {
  display.setFont(&FreeMonoBold18pt7b);
  display.setTextColor(WHITE);        // Draw white text
  display.setCursor(0, 50);
  display.print(mlx.readObjectTempC(),1);
  display.drawCircle(92, 35, 3, WHITE);
  display.setCursor(100, 50);
  display.print("C");
  display.display();
}

Add Battery, Switch and Buzzer

DIY Thermogun with battery and buzzer as alarm

The Code with alarm

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_MLX90614.h>
#include <Fonts/FreeMonoBold18pt7b.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

float temperature;

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

void setup() {
  Serial.begin(9600);
  mlx.begin();
  pinMode(4, OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
}

void loop() {
  temperature = mlx.readObjectTempC();
  if (temperature > 37) {
    digitalWrite(4, HIGH);
  } else {
    digitalWrite(4, LOW);
  }
  printText();
  delay(500);
  display.clearDisplay();
}

void printText() {
  display.setFont(&FreeMonoBold18pt7b);
  display.setTextColor(WHITE);        // Draw white text
  display.setCursor(0, 50);
  display.print(temperature, 1);
  display.drawCircle(92, 35, 3, WHITE);
  display.setCursor(100, 50);
  display.print("C");
  display.display();
}

Add Button to Operate thermogun

And if you want thermogun only measure the temperature when button is pressed. Then you need to add button and add more lines to the sketch of arduino.

Schematic

DIY thermodun with button

The Code

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_MLX90614.h>
#include <Fonts/FreeMonoBold18pt7b.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

float temperature;

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

void setup() {
  Serial.begin(9600);
  mlx.begin();
  pinMode(4, OUTPUT);
  pinMode(7, INPUT_PULLUP);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
}

void loop() {
  if (digitalRead(7) == LOW) {
    temperature = mlx.readObjectTempC();
    if (temperature > 37) {
      digitalWrite(4, HIGH);
    } else {
      digitalWrite(4, LOW);
    }
    printText();
    delay(500);
  }
  display.clearDisplay();
}

void printText() {
  display.setFont(&FreeMonoBold18pt7b);
  display.setTextColor(WHITE);        // Draw white text
  display.setCursor(0, 50);
  display.print(temperature, 1);
  display.drawCircle(92, 35, 3, WHITE);
  display.setCursor(100, 50);
  display.print("C");
  display.display();
}

3D Printed Case

If you want case using 3D printer. I have designed also for you.

casing termogunDownload