Infrared Thermometer in Acrylic Box

Recently, I saw many Makers publishing their own DIY thermometers. I decided to follow suit, but the sensors are too hard to find! Out of stock everywhere. After some twists and turns, I still got MLX90614. Although I prefer 90615, it is better than nothing. For the convenience of wiring, the module is shown at the front.

(Notice: all the relevant pictures are shown in order at the front. Thanks Apogeeweb for providing me with inspiration and related materials. For more info about Infrared Thermometer click here.)

The main control board uses Arduino Nano so that the size of the temperature detector can be made smaller. After all, no one wants to take a big box to measure the temperature! It is also possible to use Arduino Pro Mini, but you have to prepare another USB to TTL. Well, I think Nano is convenient.

I hope that there is a screen that can display, and also a buzzer, to inform the user that the measurement is started and completed. Both the MLX90614 and the OLED display screen are I2C, so a breadboard of appropriate size is needed to assist the Nano connection. It happens that there is adhesive foam glue on the bottom of the breadboard, which is convenient for us to fix the Nano.

The last part is the power supply. I have referred to the power supply options used by many Makers. To meet the power supply requirements of Arduino 5V, it is nothing more than direct use of 9V batteries or two 18650 lithium batteries. Two 18650s take up too much space, and the 9V battery can only be used once, so I decided to use a booster board with a charging function, and the battery uses a sheet-shaped polymer lithium battery.

After deciding the main control board and the modules to be used, let's start wiring! The first is OLED. For wiring, please refer to the table and picture.

Next is MLX90614. For wiring, please refer to the table and picture.

Next is the buzzer, please refer to the table and picture for wiring.

The last is the power supply. We first connect the lithium battery to the booster board. The booster board will boost the voltage to 5V, and then connect the booster board to the Arduino Nano for power supply. For wiring, please refer to the table and pictures.

The wiring is completed as shown in the figure.

Both MLX90614 and OLED use Adafruit's library. The program flow is shown in the picture.

Program and library download