Arduino MLX90614: Read Non-Contact Temperature Values | ShillehTek

May 14, 2026

Project

Build an Arduino MLX90614 non-contact IR thermometer that reads ambient and object temperature over I2C, perfect for safe touch-free measurements with ShillehTek.

10 min Beginner3 parts

Project Overview

Arduino + MLX90614: In this tutorial, you will wire an MLX90614 non-contact IR thermometer to an Arduino and read both ambient and object temperature over I2C in the Serial Monitor.

The MLX90614 is a non-contact infrared thermometer that reads object temperature from up to a few centimetres away. It is the same sensor used in many forehead thermometers, food-safety tools, and monitoring setups.

Time: ~10 minutes
Skill level: Beginner
What you will build: An Arduino reading both ambient and object temperature over I2C.

Arduino MLX90614 (GY-906) infrared temperature sensor module used for non-contact ambient and object temperature readings — The MLX90614 (GY-906) has 4 pins and outputs both ambient and object temperature.

Parts List

From ShillehTek

MLX90614 Pre-Soldered IR Temperature Sensor - the non-contact IR thermometer module (I2C).
Arduino Nano V3.0 Pre-Soldered - reads the sensor over I2C and prints temperatures to Serial.
120 PCS Dupont Jumper Wires - for quick VCC, GND, SDA, and SCL connections.

External

USB cable - to power and program the Arduino
Arduino IDE - to upload the sketch

Note: The MLX90614 itself is a 3 V device, but the GY-906 breakout includes an on-board regulator so it can accept 3 to 5 V on VCC.

Step-by-Step Guide

Step 1 - Inspect the module

Goal: Identify the MLX90614 breakout parts and confirm the pin labels before wiring.

What to do: Check the front for the IR sensor can and make sure the sensor window is clean. Then locate the 4-pin header labels (VCC, GND, SDA, SCL) on the board or silkscreen.

MLX90614 GY-906 breakout front view showing the IR sensor can used for non-contact temperature sensing — The metal can is the IR sensor. Keep its window clean.

Back of the MLX90614 GY-906 breakout showing regulator, pull-up resistors, and capacitors for I2C operation — Pull-ups, regulator, and bypass capacitors are on the back.

MLX90614 pinout diagram labeling VCC, GND, SDA, and SCL for Arduino I2C wiring — 4 pins: VCC, GND, SDA, SCL.

Expected result: You know which pins are power and which pins are I2C (SDA and SCL).

Step 2 - Wire it to the Arduino (I2C)

Goal: Connect power and I2C so the Arduino can communicate with the MLX90614.

What to do: Wire VCC and GND to the Arduino power pins, and connect SDA and SCL to the Arduino I2C pins for your board. Use the wiring diagram below as a reference.

MLX90614 GY-906 wired to an Arduino using four jumper wires for VCC, GND, SDA, and SCL (I2C) — I2C wiring: VCC, GND, SDA, and SCL.

Expected result: The sensor is powered and the I2C lines are connected, ready for code upload.

Step 3 - Install the library and upload the sketch

Goal: Load a working example that prints ambient and object temperature readings.

What to do: In the Arduino IDE, install Adafruit MLX90614 using the Library Manager. Then paste and upload the sketch below.

Code:

#include <Wire.h>
#include <Adafruit_MLX90614.h>

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

void setup() {
  Serial.begin(9600);
  if (!mlx.begin()) { Serial.println("MLX not found"); while (1); }
}

void loop() {
  Serial.print("Ambient="); Serial.print(mlx.readAmbientTempC(), 1);
  Serial.print(" C  Object="); Serial.print(mlx.readObjectTempC(), 1);
  Serial.println(" C");
  delay(500);
}

Expected result: The sketch uploads successfully and the Arduino begins streaming temperature values over Serial.

Step 4 - Read temperatures in the Serial Monitor

Goal: Verify the sensor is measuring and reporting different object temperatures.

What to do: Open the Serial Monitor (9600 baud). Aim the sensor at different targets (for example, a hot drink, your skin, or a radiator) and watch the object temperature change.

Arduino Serial Monitor output showing MLX90614 ambient and object temperature values updating in real time — Different targets produce different object temperatures.

Expected result: You see both Ambient and Object temperatures updating about twice per second.

Step 5 - Expand the project

Goal: Use the same sensor readings in a real project idea.

What to do: Choose one direction below and build from the same wiring and sketch (for example, add a display, logging, or alarm logic).

Build a fingertip thermometer with an OLED readout
Monitor a 3D printer hot-end externally for thermal-runaway protection
Cook food by tracking surface temperature of a steak in real time
Detect overheating components on a busy PCB

Expected result: You have a clear next step for turning MLX90614 readings into a complete build.

Conclusion

You built an Arduino MLX90614 non-contact thermometer that reads ambient and object temperature over I2C and prints the results to the Serial Monitor. This gives you touch-free temperature measurement using only four wires and a simple library.

Want the exact parts used in this build? Grab them from ShillehTek.com. If you want help customizing this project or building a thermal-monitoring feature into your product, check out our IoT consulting services.

Attribution: The MLX90614 photos and wiring diagrams in this tutorial are credited to Instructables.