Updated: May 10, 2022
Relative Humidity and temperature are very important for a comfortable living environment. Both the parameters change with the climatic condition. To predict the climatic condition many costly instruments are used by the meteorological centers to measure the temperature and humidity. The instruments used in the meteorological centers are very costly to afford.
In this article, let us learn to implement a simple project to measure the temperature and humidity of the room by using a low-cost DHT11 sensor interfacing with an Arduino board.
Let us first start with the requirements for the implementation of the project.
A breadboard is an essential component that is in a rectangular shape with small holes in it that are used to insert the components to test the circuits. The connections are not fixed and can be varied. In a breadboard, the holes in one horizontal line are in series connection with each other. Breadboards are made from plastic or wood and come in all shapes, sizes, and even different colors, the most commonly used sizes for designing the circuits are "full-size," "half-size," and "mini" breadboards.
Buy Breadboard from here.
2. Arduino UNO
#Arduino board is a microcontroller that is used to accept inputs from sensors connected and provide an output action on the desired device connected to it. The sensor inputs can be from light-detecting sensors, motion sensors (Ultrasonic or IR), temperature sensors, etc. The output from this device can be received through other output devices such as LED, Buzzer, Serial monitor, etc.
Buy Arduino UNO from here.
3. DHT11 Sensor Module
The DHT11 #sensor is a low-cost digital sensor used to measure temperature and humidity levels. The sensor contains a capacitive humidity sensor for detecting the humidity level. For measuring the temperature this sensor employs a thermistor that has a negative temperature coefficient. It is small-sized and has an operating voltage from 3 to 5 volts.
The sensor has four pins namely - supply pin (Vcc), Output pin (Data), No connection (NC), and Ground pin (Gnd). The DHT11 has a module consists of three pins. They are the supply pin (Vcc), the output pin (Data), and the Ground pin (Gnd).
Buy DHT11 Sensor Module from here
4. Jumper Wires
These are the main components that are used to establish the connections between different devices of the circuit.
Buy Jumper Wires from here.
5. USB Cable
This cable is used to connect the Arduino board to the power supply. It also helps in the transmission of data.
Buy USB Cable from here.
1. Arduino IDE
The connection between the Arduino board and the DHT11 sensor by using jumper wires involves simple steps:
The sensor has four pins in which only three pins are used. They are the supply pin (Vcc), the output pin (Data), and the Ground pin (Gnd). Insert the sensor in the holes of the breadboard
The Supply pin (Vcc) is connected to the 5V of the Arduino board using a Red jumper wire.
The output pin (Data) is connected to the digital pin 2 of the Arduino board using a blue jumper wire.
Finally, the ground pin (GND) is connected to the ground terminal of the Arduino board.
Note: Please change the file extension to .ino(Arduino IDE) file format before you upload the code to the Arduino board.
The Working of the #DHT11 Sensor to measure the temperature and humidity in the room involves simple steps. The below image shows the picture of the circuit when the code is not applied.
After uploading the code based on the parameter to be measured, the sensor is ready to fetch the data which is indicated with the glowing of the #LED light.
If the coding to measure temperature is uploaded to the board it displays the temperature of the room in both Celsius and Fahrenheit scale. When the coding for Humidity is uploaded it displays the real-time Humidity of the room. For further understanding, Video explanations with the practical implementation, are given in these two videos to measure temperature and humidity using the DHT11 sensor.
Video By - Abhishek Goud
Take the initial step to design the circuit, learn to interface the DHT11 sensor with Arduino, and develop your own coding with creative combinations. With this basic tutorial, we can also develop several advanced projects in numerous applications include #IoT weather stations, condition monitoring, etc.