KY-013 Analog Temperature Sensor Module – NTC Thermistor for Arduino & ESP32

The KY-013 Analog Temperature Sensor Module is a compact temperature-sensing module designed to measure ambient temperature using an NTC (Negative Temperature Coefficient) thermistor.

As temperature increases, the thermistor's resistance decreases, producing a corresponding change in analog output voltage. This signal can be read by a microcontroller's analog-to-digital converter (ADC) to estimate temperature.

The KY-013 is ideal for Arduino, ESP32, Raspberry Pi projects with an external ADC, environmental monitoring, robotics, and educational electronics applications.

Key Features

• Model: KY-013
• Sensor Type: NTC Thermistor
• Temperature Measurement: Analog
• Typical Thermistor Resistance: 10kΩ at 25°C
• Typical Temperature Range: -55°C to +125°C (Thermistor Dependent)
• Operating Voltage: 3.3V–5V DC
• Output Type: Analog Voltage
• Interface: 3 Pins (S, +, -)
• Compact and Lightweight Design
• Suitable for Temperature Monitoring and Microcontroller Projects

Technical Specifications

Pin Configuration

Arduino Connection Example

The Arduino reads the analog voltage generated by the thermistor circuit and converts it into an estimated temperature using the thermistor's resistance-temperature characteristics.

Arduino Example Code

The following example assumes a 10kΩ NTC thermistor with a B-value of 3950K, connected in a voltage divider with a 10kΩ fixed resistor between VCC and the analog output.

#include <math.h>

const int sensorPin = A0;
const float seriesResistor = 10000.0;
const float nominalResistance = 10000.0;
const float nominalTemperature = 25.0;
const float beta = 3950.0;

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

void loop() {
  int adcValue = analogRead(sensorPin);

  if (adcValue <= 0 || adcValue >= 1023) {
    Serial.println("Reading out of range");
    delay(1000);
    return;
  }

  float resistance = seriesResistor *
                     adcValue / (1023.0 - adcValue);

  float temperatureK = 1.0 /
    ((1.0 / (nominalTemperature + 273.15)) +
     (log(resistance / nominalResistance) / beta));

  float temperatureC = temperatureK - 273.15;

  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" C");

  delay(1000);
}

Note: The calculation depends on the module's actual voltage-divider arrangement and thermistor specifications. Some KY-013 versions use the opposite resistor arrangement and require a different resistance formula.

Applications

• Ambient Temperature Monitoring
• Arduino and ESP32 Projects
• Environmental Monitoring Systems
• Robotics and Automation
• Electronic Temperature Indicators
• DIY Weather Stations
• Temperature-Controlled Fans
• Educational STEM Projects
• Electronic Prototyping
• Home Automation

Important Notes

• The KY-013 is an analog temperature sensor, not a digital temperature sensor.
• It requires an ADC input to measure temperature.
• Raspberry Pi boards do not have built-in general-purpose analog inputs; an external ADC such as the MCP3008 or ADS1115 is required.
• Temperature accuracy depends on thermistor tolerance, calibration, ADC resolution, and the correct resistance-conversion formula.
• The stated temperature range refers to typical thermistor characteristics and does not guarantee the same operating range for every assembled module.
• The KY-013 is not waterproof and should not be used directly in liquids.
• For ESP32, power the module at 3.3V to keep its analog output within the ADC's allowable voltage range.
• Verify the thermistor's B-value and voltage-divider configuration for accurate measurements.

Package Includes

1 × KY-013 Analog Temperature Sensor Module