Introduction:
In this tutorial, we will learn about the KY-028 module, what is an NTC Thermistor and we will build a simple project using the KY-028 module and an Arduino.
Digital Temperature Sensor Module KY-028:
The KY-028 Module will be our main component for this tutorial. This module has an NTC Thermistor, and an LM393 differential comparator mounted on a breakout board with a potentiometer and several resistors. Figure 1 shows the module as seen in fritzing.
Pin Out:
The KY-028 module has four pins.
| Pin | Description |
|---|---|
| A0 | Analog Output |
| G | Ground |
| (+) | +5V |
| D0 | Digital Output |
What is a NTC Thermistor?
An NTC Thermistor is a kind of resistor with a Negative Temperature Coefficient. Having a negative temperature coefficient means its resistance decreases with increasing temperature and vice-versa.
Project:
Arduino Digital Thermometer:
After learning about the KY-028 module and the NTC Thermistor, it is now time to build a project using the module. Our project will get the analog and digital signals from the KY-028 module, display it on the serial monitor, and control the Arduino’s built-in LED.
Components:
For this project, we need the following components:
- Arduino Uno board (1 pc.)
- KY-028 Digital Temperature Sensor Module (1 pc.)
- Jumper wires
Wiring Diagram:
Figure 2 shows the connection between the Arduino Uno and the KY-028 Digital Temperature Sensor Module.
The KY-028 module pins are connected to the Arduino Uno board as follows:
| Component Pin | UNO Board Pin |
|---|---|
| A0 | A0 |
| G | Ground |
| (+) | +5V |
| D0 | 8 |
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-028.ino and upload it to your Arduino board.
// Arduino and KY-028 module
void setup ()
{
pinMode (13, OUTPUT); // built-in LED pin set to output
pinMode (8, INPUT); // module digital output connected to Arduino pin 8
Serial.begin(9600); // initialize serial
}
void loop ()
{
Serial.print("Analog pin: "); // display analog and digital values to serial
Serial.print(analogRead(A0));
Serial.print(" | Digital pin: ");
if (digitalRead(8) == HIGH) {
Serial.println("High");
digitalWrite (13, HIGH); // if analog value is higher than threshold,
// switch-On built-in LED
}
else {
Serial.println("Low");
digitalWrite (13, LOW);
}
delay(100); // wait 100 milliSeconds
}
Project Test:
Apply power to your Arduino Uno board and open the Serial Monitor in the Arduino IDE. Arduino will output the analog value sent by the module to the serial monitor. If the value reaches the threshold setpoint set by VR1, the built-in LED of the Arduino will also light-up. Adjust the threshold by turning VR1.
