What is the MF52A Sensor?

The MF52A is a thermistor - a type of resistor whose resistance changes with temperature.

• NTC Type: Negative Temperature Coefficient - resistance decreases as temperature increases
• Resistance at 25°C: Typically 10kΩ (10,000 ohms)
• Temperature Range: -55°C to +125°C
• Applications: Room temperature monitoring, weather stations, HVAC systems

How Does a Thermistor Work?

A thermistor's resistance changes predictably with temperature:

• Cold Environment: High resistance (more opposition to current flow)
• Hot Environment: Low resistance (less opposition to current flow)

By measuring the resistance, we can calculate the temperature using the Steinhart-Hart equation or a simplified B-parameter equation.

Key Point: Arduino can't measure resistance directly - it measures voltage. We'll use a voltage divider circuit!

Wiring the MF52A to Arduino

We'll create a voltage divider circuit with two resistors:

• Component 1: MF52A thermistor (variable resistance)
• Component 2: 10kΩ fixed resistor

Connections:

• 5V → Thermistor → A0 (analog pin) → 10kΩ resistor → GND
• The middle connection (between thermistor and fixed resistor) goes to analog pin A0

This circuit converts changing resistance into changing voltage that Arduino can read!