Arduino IR thermometer project

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Arduino IR thermometer project

Arduino IR thermometer using the MLX90614 IR temperature sensor from

In this video we learn how to build a very usefull project. An Arduino IR thermometer, using the MLX90614 Infrared temperature sensor and the a Nokia 5110 LCD display shield. We are also using an Arduino Uno but you can use any Arduino board you like.




A few weeks ago webstore contacted me and asked me if I wanted any items to build projects with them. After searching among the cool items they offer I discovered two gems. The Nokia 5110 LCD shield for Arduino and the MLX90614 IR temperature sensor. Since the Nokia 5110 is my favorite display to use with Arduino, this shield became my favorite at once since it makes things so much easier. We don’t need to connect wires any more in order to use it which makes prototyping a lot faster. It also has a small joystick embedded. And the price of it is less than 4$, which is great!

I combined these two items that was kind enough to send me in order to build this Arduino IR thermometer! You can find links for the parts in a link in the description of the video.
The project is capable of measuring the temperature of an object without touching it, from a small distance. It can measure temperatures from -70 degrees Celsius to 380 degrees. The accuracy is about 0.5 degree in room temperature which is great! Let’s see the project in action. If I point the sensor at the cutting mat, the temperature it measures is

Now, if I point the sensor at my palm, the temperature rises to 32 . You may wonder why it does not measure 36.6 degrees Celsius. That’s because the skin temperature of a human, is different of the body temperature which is 36.6. The normal skin temperature of a person is between 32 and 35 degrees Celsius. Let’s measure the temperature of more objects…. Cool isn’t it?

Let’s now see how to build this project. All we need is an Arduino Uno, the Nokia 5110 LCD shield and the MLX90614 IR sensor module. The sensor uses the I2C protocol so, it is extremely easy to make it work with Arduino.

Vcc goes to Arduino 5V. Ground goes to Arduino GND. SCL goes to analog pin 5 of the Arduino Uno. Lastly, SDA goes to analog pin 4 of the Arduino. As you can see the shield has all the pins of the Arduino Uno exposed so it is very easy to work with it. Now we are ready to power up the project. As you can see, after displaying a splash screen for a few seconds, the project starts measuring the temperature. Now let’s see the software side of the project.
The code of the project is very easy as well. We use the Adafruit MLX90614 library for the sensor, and the Nokia 5110 Graph library for the display. At first we define if we want the temperature to be displayed in degrees Celsius or Fahrenheit. Next, the code, all it does is to read the object temperature from the sensor and display it on the screen. The sensor can also measure ambient temperature but we are not using this feature today. If you don’t have the LCD shield but you have a Nokia 5110 LCD display you can use the code with a small change. Just change the pin number in this line of code here to match your connection. You can watch my previous tutorial on how to use the Nokia 5110 display in order to find out how to connect your display. As always you can find the code of the project in the description of the video.








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One Comment

  1. Alex January 23, 2017 at 8:33 am - Reply

    Hi dear. Thank you for your description. But.
    I am try to use this provided code, but in time of compilation we receive mistake:

    fatal error: Wire.h: No such file or directory
    #include “Wire.h”

    Tell me please, how to solve it?

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