GY-906 | GUILCOR SENSORS

GY-906
Temperature sensors

Ready-to-use infrared temperature sensor module based on MLX90614, ideal for rapid prototyping and electronics projects.

Maximum precision
+/- 0,2°K

Minimum temperature
-70°C

Maximum temperature
+380°C

Resolution
0,02°C

Power supply voltage

3,0→5,5V

Response time

0,1 à 1 s

Typical current
1,5 mA

Price
Medium

What is a GY-906 sensor ?

The GY-906 is a ready-to-use digital infrared module based on the MLX90614 sensor from Melexis.

It allows for the remote measurement of an object's surface temperature using an integrated IR thermopile.

The module includes:

the MLX90614ESF (main sensor),
a 3.3 V regulator,
I²C pull-up resistors,
and sometimes a PWM output pin.

💡 In simple terms: it only requires 4 wires to use: VCC, GND, SDA, SCL.

Operating principle

Same principle as the MLX90614: the sensor measures the infrared radiation emitted by objects and converts the thermopile voltage into temperature.

The values (ambient temperature + object temperature) are digitized and corrected by the internal DSP.

Standard formula:

T(°C) = (Brut value x 0,02) - 273,15

Example of digital conversion (Arduino / ESP32)

GY-906
│
├─ VCC → 3.3V / 5V
├─ GND → GND
├─ SDA → A4 (ou GPIO21)
└─ SCL → A5 (ou GPIO22)

💡 No external resistance needed: the module is already equipped.

Example of I2C reading (Arduino)

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

Adafruit_MLX90614 mlx = Adafruit_MLX90614();

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

void loop() {
  Serial.print("Ambiante: "); 
  Serial.print(mlx.readAmbientTempC());
  Serial.print(" °C | Objet: "); 
  Serial.print(mlx.readObjectTempC());
  Serial.println(" °C");
  delay(500);
}

✅ Typical result:

Ambient: 24.8 °C | Object: 36.5 °C

Application areas

🧠 Connected objects (IoT) and home automation

🏥 Medical and portable thermometers

⚙️ Monitoring of motors, bearings, electronic boards

🧪 Experimental measurements and test stations

🤖 Robotics and thermal obstacle detection

Should I choose an GY-906 sensor?

Strengths points

🔌 Ready to use
→ Integrated regulator, resistors, and connectors — plug & play on Arduino.
🎯 Very precise and stable
→ Based on the MLX90614ESF, factory calibrated (±0.2 K over 0–100 °C).
🌡️ Contactless measurement
→ Ideal for detecting objects, humans, or hot surfaces from a distance.
💰 Excellent value for money
→ Same accuracy as the bare MLX90614, at a lower cost.

Weaknesses points

📏 Fixed field of vision (~35°)
→ No narrow version integrated on the standard module.
🧹 Sensitive to dust and airflow
→ Exposed lens, requires protection if used in an open environment.
📦 Limited calibration
→ Emissivity set to 1.0, requires software correction for reflective materials.

Useful information

Here is some useful information regarding the GY-906 sensors.

Module clamping

Brooch	Name	Description
1	VCC	Power supply 3.3 → 5.5 V
2	GND	Mass
3	SCL	I²C Clock
4	SDA	I²C Data

💡 Some boards include a "PWM" pin for analog signal output.

Connection example (Arduino UNO)

Arduino UNO ─── GY-906 5V ──────────── VCC GND ─────────── GND A4 (SDA) ───── SDA A5 (SCL) ───── SCL

✅ No external power supply or resistance needed.

Useful registers (identical to the MLX90614)

Address (hex)	Name	Description
0x03	Tambient	Internal temperature
0x07	Tobject	Measured temperature
0x2E	Adresse I²C	Programmable
0x04	Emissivity	Material adjustment