Introduction
In this tutorial, we will learn about the KY-013 module, what is an NTC Thermistor and we will build a simple project to read ambient temperature using the KY-001 module and an Arduino.
Temperature Sensor Module KY-013
The KY-013 Module will be our main component for this tutorial. This module has an NTC Thermistor and mounted on a breakout board with a 10K-ohm resistor. Figure 1 shows the module as seen in fritzing.
Pinout
The KY-013 module has three pins.
| Component Pin | Arduino Uno board Pin |
|---|---|
| (-) | GND |
| middle | +5V |
| S | Signal |
What is an NTC Thermistor?
An NTC Thermistor is a Negative Temperature Coefficient resistor. This means that the resistance is inversely proportional to temperature. The resistance increases when temperature decreases and vice-versa.
Project - Arduino Analog Ambient Thermometer
After learning about the KY-013 module and the NTC Thermistor, it is now time to build a project using the module. Our project will read the resistance value from the KY-013 module. The value obtained will then be used to calculate the temperature and display it on the serial monitor.
Components
For this project, we need the following components:
- Arduino Uno board (1 pc.)
- KY-013 Temperature Sensor Module (1 pc.)
- Jumper wires
Wiring Diagram
Figure 2 shows the connection between the Arduino Uno and the KY-013 Temperature Sensor Module.
The KY-013 module pins are connected to the Arduino Uno board as follows:
| Component Pin | Arduino Uno board Pin |
|---|---|
| (-) | GND |
| middle | +5V |
| S | A0 |
The Code
Below is the Arduino sketch for our project. I have added comments to explain important parts of the code. Save the code as KY-013.ino and upload it to your Arduino board.
// Arduino and KY-013 tutorial
void setup() {
Serial.begin(9600); // initialize serial interface with baud 9600bps
}
void loop() {
// Read value from module connected at pin A0
int V_input = analogRead(A0);
// calculate thermometer resistance by comparing it to the modules onboard 10K-ohm resistor
float R_ohms = 10000 * (1023.0 / (float)V_input - 1.0);
// calculate temperature in Celsius
float temp_C = (1.0 / (0.001129148 + (0.000234125*log(R_ohms)) + 0.0000000876741*log(R_ohms)*log(R_ohms)*log(R_ohms)))-273.15;
// output result to serial
Serial.print("Temperature (degC): ");
Serial.println(temp_C);
}
Project Test
Apply power to your Arduino Uno board and open the Serial Monitor in the Arduino IDE. Arduino calculates the temperature based on the reading from the KY-013 module connected to pin A0 and displays the result on the serial monitor every second.
