Cricklewood Electronics

What is the KY-015 DHT11 Module?

The KY015 is a temperature and humidity module for Arduino and other microcontroller projects

 

KY-015 module has a DHT-11 digital temperature and humidity sensor and a resistor. The DHT11 uses a thermistor for the temperature sensing and a capacitive humidity sensor along with an internal IC to give a digital output for both temperature and humidity.

 

Voltage : 3.3 to 5VDC

Humidity range : 20% to 90% @ 5% RH accuracy

Temperature range : 0C to 50C at 2C accuracy

Size 30x15mm

 

How Can I use the KY-015 Module to monitor temperature and humidity?

Here is an example project to measure temperature and humidity using the KY015 module and an Arduino Uno

 

Temperature and Humidity Sensor

In this project, we will be building a weather station that can measure both temperature and humidity.

This is what you will need:

Tools

Jumper Leads (male to female)

 

Components

Arduino Uno x 1 or Arduino Nano x 1

KY-15 sensor module

 

Libraries

DHT Sensor Library

Adafruit Unified Sensor Library

 

Step 1

First you will need to assemble the project. Connect everything together using the wiring diagram bellow for reference.

 

Connect the KY-015 sensor module to the Arduino

KY-015                        Arduino   

Ground - - - - - - - - - -  Ground
Vcc - - - - - - - - - - - - - - 3v3
Data - - - - - - - - - - - - -  A0

A 10KΩ pull-up resistor is built in to the KY-015

 

Step 2

Connect your Arduino to the PC and install the above Libraries. If you don’t know how to do this, CLICK HERE and follow the “Installing Arduino Libraries” section.

 

Step 3

We can now create the code to get this all working

First, delete the code in the IDE window, then include the aforementioned libraries:  

 
<code class="language-css">#include "DHT.h"</code>

This bit of code imports the DHT library and links it to the sketch.

 
<code class="language-css">#define DHTPIN A0 
#define DHTTYPE DHT11</code>

This bit of code defines which pin is KY015 connected to and sets the type of sensor (KY015 uses DHT11)

 
<code class="language-css">DHT dht(DHTPIN, DHTTYPE);</code>

This bit of code initialises the sensor

 
<code class="language-css">void setup() { 
  Serial.begin(115200); 
  Serial.println(F("DHT11 test!")); 
  dht.begin(); 
}</code>

The setup bit of code initialises serial output with baud rate of 115200 and prints DHT11 test! In the console

 
<code class="language-css">void loop() { 
      delay(2000);</code>

This bit makes the Arduino wait 2 seconds between measurements

 
<code class="language-css">  float h = dht.readHumidity();</code>

Read humidity from the sensor

 
<code class="language-css">  float t = dht.readTemperature();</code>

Read temperature from the sensor

 
<code class="language-css">  Serial.print(F("Humidity: ")); 
  Serial.print(h); 
  Serial.print(F("%  Temperature: ")); 
  Serial.print(t); 
  Serial.println(F("°C ")); 
}</code>

Print the latest reading in serial monitor

 

 
<code class="language-css">#include "DHT.h" 
 
#define DHTPIN A0     // Digital pin connected to the DHT sensor 
#define DHTTYPE DHT11   // DHT 11 
DHT dht(DHTPIN, DHTTYPE); 
 
void setup() { 
  Serial.begin(115200); 
  Serial.println(F("DHT11 test!")); 
 
  dht.begin(); 
} 
 
void loop() { 
  delay(2000); 
 
  float h = dht.readHumidity(); 
  float t = dht.readTemperature(); 
 
  Serial.print(F("Humidity: ")); 
  Serial.print(h); 
  Serial.print(F("%  Temperature: ")); 
  Serial.print(t); 
  Serial.println(F("°C ")); 
}</code>