Sensors

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 DHT11digital 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 nedd 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:  

 
#include "DHT.h"

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

 
#define DHTPIN A0 
#define DHTTYPE DHT11

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

 
DHT dht(DHTPIN, DHTTYPE);

This bit of code initialises the sensor

 
void setup() { 
  Serial.begin(115200); 
  Serial.println(F("DHT11 test!")); 
  dht.begin(); 
}

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

 
void loop() { 
	  delay(2000);

This bit makes the Arduino wait 2 seconds between measurements

 
  float h = dht.readHumidity();

Read humidity from the sensor

 
  float t = dht.readTemperature();

 
  Serial.print(F("Humidity: ")); 
  Serial.print(h); 
  Serial.print(F("%  Temperature: ")); 
  Serial.print(t); 
  Serial.println(F("°C ")); 
}

Print the latest reading in serial monitor

Example project: 

Step 1

First, you will need to connect the HCSR04 sensor to the Arduino. Simply use the male to female jumper leads to connect the two together as described below and in fig.1:

HCSR04                                      Arduino

VCC-----------------------------------------5V

Trig------------------------------------------D3

Echo----------------------------------------D2

GND---------------------------------------GND

 

Step 2

Solder the KY1602 module onto the 1602 LCD screen. Pin 1 on the KY1602 module is the one closest to the 4 data and power pins. Once soldered, you can now connect the LCD display to the Arduino as shown in fig. 1.


                                                                               fig. 1

 

Step 3

Connect the Arduino to a computer and install the libraries mentioned above. If you need help installing the libraries, CLICK HERE for a quick tutorial.

 

Step 4
You can now start writing the code to get this all working:

First, clear the IDE window. Then, include the aforementioned libraries:
 

 
    
#include <HCSR04.h> 
#include <LCD_I2C.h> 
    

DS18B20 High Accuracy Digital Thermometer.

DS18B20 Temperature Probe x 1

Arduino Uno x 1 or Arduino Nano x 1

LCD1602B LCD Screen x 1

KY1602 Parallel to Serial Converter x 1

Libraries

DS18B20 V1.0.0 Arduino Library

OneWire

LiquidCrystal I2C

Step 1

First, you will need to connect the probe to the breadboard. This should be easy to do since the probe comes with pre-tinned leads. Simply push the ends of the leads into the breadboard sockets and use a 4.6kΩ pull-up resistor on the data pin as shown in fig.1. Now, you will need to connect the Arduino to the breadboard. Use the jumper leads to connect the male to male jumper leads to connect the power, ground and digital pin to the breadboard. 

 

Step 2

Solder the KY1602 module onto the 1602 LCD screen. Pin 1 on the KY1602 module is the one closest to the 4 data and power pins. Once soldered, you can now connect the LCD display to the Arduino as shown in fig.1:

 

Fig. 1

Step 3

Connect the Arduino to your computer and install the libraries mentioned above. If you need help installing the libraries, CLICK HERE for a quick tutorial.
 

Step 4

You can now start writing the code to get this all working: 


First, clear the IDE window. Then, include the aforementioned libraries:

 
 
#include <DS18B20.h> 
#include <LCD_I2C.h> 
 

Initialize the KY1602 I2C LCD driver (address 0x27 in this example) and specify the LCD display (in this case 16 characters, 2 rows):

 
    
DS18B20 ds(12); 
LCD_I2C lcd(0x27, 16, 2); 
    

Initialize the LCD display and turn on the LCD backlight. This is done inside the void setup function:

 
    
void setup() { 
lcd.begin(); 
lcd.backlight(); 
} 
    

Start a while loop. This is done inside the void loop function:

 
    
void loop() { 
while (ds.selectNext()) { 
    

Set the cursor to the first character and display the temperature in ºF and ºC:

 
    
lcd.setCursor(0,0); 
  lcd.print(ds.getTempC()); 
  lcd.print((char)223); 
  lcd.print("C"); 
  lcd.setCursor(0,1); 
  lcd.print(ds.getTempF()); 
  lcd.print((char)223); 
  lcd.print("F"); 
  } 
    

Choose how often to update the screen (in this case, 800ms):

 
    
  delay(800); 
} 
    

The completed code should look like this:

 
    
#include <DS18B20.h> 
#include <LCD_I2C.h> 
 
DS18B20 ds(12); 
LCD_I2C lcd(0x27, 16, 2); 
 
void setup() { 
  lcd.begin(); 
  lcd.backlight(); 
} 
 
void loop() { 
  while (ds.selectNext()) { 
  lcd.setCursor(0,0); 
  lcd.print(ds.getTempC()); 
  lcd.print((char)223); 
  lcd.print("C"); 
  lcd.setCursor(0,1); 
  lcd.print(ds.getTempF()); 
  lcd.print((char)223); 
  lcd.print("F"); 
  } 
  delay(800); 
}