KY-028 Thermistor Temperature Sensor Module

Description

KY-028 Thermistor Temperature Sensor Module

The KY-028 uses an NTC thermistor to respond to temperature changes. Its LM393 comparator compares the thermistor signal with an adjustable reference set by the onboard 3296W potentiometer and provides a digital output for microcontrollers such as Arduino.

Specifications

• Temperature range: −55 °C to +125 °C (as stated in the source listing)
• Accuracy: ±0.5 °C (as stated in the source listing)
• Operating voltage: 3.3–5.5 V
• Output: digital D0
• Dimensions: 36 × 15 mm
• Main components: NTC thermistor, LM393 comparator and 3296W potentiometer

How it works

The NTC thermistor’s resistance decreases as temperature rises. The LM393 compares the sensor level with the potentiometer-adjusted reference and switches the digital output HIGH or LOW. The potentiometer sets the switching threshold; this module’s digital output indicates a threshold crossing rather than providing a calibrated temperature reading.

Applications

• Temperature-threshold indicators
• Climate-control projects
• Educational electronics
• Home-automation projects

Pinout

• VCC: 3.3–5 V supply
• GND: ground
• D0: digital output

Using it with Arduino Uno

Basic Arduino example

const int ledPin = 13; // LED sur la carte Arduino
const int digitalPin = 2; // Sortie numérique du capteur KY-028
int digitalVal; // valeurs numériques


void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(digitalPin, INPUT);
  Serial.begin(9600);
}


void loop() {
  digitalVal = digitalRead(digitalPin); 


  if(digitalVal == HIGH) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }


  Serial.println(digitalVal);
  delay(100);
}

The basic example reads D0, turns the Arduino’s built-in LED on when the module’s digital threshold is triggered, and reports the reading in the serial monitor.

Advanced example with I2C LCD

#include <Wire.h>
#include <LiquidCrystal_I2C.h>


const int ledPin = 13;
const int digitalPin = 2;


LiquidCrystal_I2C lcd(0x27, 16, 2);


void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(digitalPin, INPUT);
  Serial.begin(9600);
  lcd.begin();
  lcd.backlight();
}


void loop() {
  int digitalVal = digitalRead(digitalPin);


  if(digitalVal == HIGH) {
    digitalWrite(ledPin, HIGH);
    lcd.setCursor(0, 0);
    lcd.print("Temperature High");
  } else {
    digitalWrite(ledPin, LOW);
    lcd.setCursor(0, 0);
    lcd.print("Temperature Low ");
  }


  Serial.println(digitalVal);
  delay(1000);
}

Advanced-example wiring

• KY-028 VCC: Arduino 5 V
• KY-028 GND: Arduino GND
• KY-028 D0: Arduino digital pin 2
• LCD VCC/GND: Arduino 5 V/GND
• LCD SCL/SDA: Arduino A5/A4

Library installation

1. In the Arduino IDE, open Sketch → Include Library → Manage Libraries.
2. Search for and install LiquidCrystal_I2C for the LCD example.

Keywords: KY-028 thermistor module, NTC temperature sensor, LM393 temperature switch, Arduino temperature threshold sensor.