KY-015 Combi-Sensor (temperature & humidity)

The DHT11 sensor is a combination of temperature and humidity sensor in a compact design. It measures temperatures from 0°C to 50°C with an accuracy of ±2°C and relative humidity from 20% to 90% with an accuracy of ±5%. Due to its low sampling rate, the sensor only provides new readings every two seconds, making it ideal for long-term measurements. The DHT11 is easy to integrate into microcontroller platforms such as Arduino and Raspberry Pi and requires no additional calibration thanks to factory calibration. Its robust design and reliability make it the optimal choice for continuous monitoring projects such as greenhouses, climate control systems and warehouse monitoring.

Pin assignment

Code Example

To load the following code example onto your Arduino, we recommend using the Arduino IDE. In the IDE, you can select the appropriate port and the correct board for your device.

The following libraries are also used for the code example:

DHT-sensor-library by Adafruit | published under the MIT License.

Adafruit Unified Sensor by Adafruit | published under the Apache License 2.0

You can easily add these libraries via the library manager of the Arduino IDE. Then copy the code below into your IDE. To upload the code to the Arduino, simply click on the upload button.

This sensor does not output its measurement result as an analog signal to an output pin, but communicates it digitally encoded.

// Adafruit_DHT Library is inserted
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>
 
// The respective input pin can be declared here
#define DHTPIN 2     
 
// The sensor is initialized
#define DHTTYPE DHT11   // DHT 11
DHT dht(DHTPIN, DHTTYPE);
 
void setup() {
  Serial.begin(9600);
  Serial.println("KY-015 Test - Temperature and humidity test:");
  // Measurement is started
  dht.begin();
}
 
// Main program loop
// The program starts the measurement and reads out the measured values
// A pause of 2 seconds is inserted between the measurements,
// so that a new measurement can be recorded during the next run.
void loop() {
  // Two seconds pause between measurements
  delay(2000);
  // Humidity is measured
  float h = dht.readHumidity();
  // Temperature is measured
  float t = dht.readTemperature();
  // Checks whether the measurements have run through without errors
  // If an error is detected, an error message is output here
  if (isnan(h) || isnan(t)) {
    Serial.println("Error when reading out the sensor");
    return;
  }
  // Output to the serial console
  Serial.println("-----------------------------------------------------------");
  Serial.print(" Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print(" Temperature: ");
  Serial.print(t);
  Serial.println(" °C ");
  Serial.println("-----------------------------------------------------------");
  Serial.println(" ");
}

Please note that the sensor provides a new measurement result only about every 2 seconds.