This is a very popular, ultra low cost DHT11 digital temperature and humidity sensor. It uses a capacitive humidity sensor, and a thermistor to measure the surrounding air temperature. The result is available via a digital signal on the data pin (no analog input pins needed).
The Digital Temperature Humidity Sensor Module sensor makes it really easy to add humidity and temperature data to your DIY electronics projects. It’s perfect for remote weather stations, home environmental control systems, and farm or garden monitoring systems.
- Can detect surrounding environment of the humidity and temperature
- DHT11 sensor adopts
- Humidity measurement range: 20% ~90%
- Humidity measurement error: ±5%
- Temperature measurement range: 0 Degrees Celsius~60 Degrees Celsius
- Temperature measurement error: ±2 Degrees Celsius
- Operating voltage:DC5 V
- Output form:digital
- Has fixed bolt hole and easy installation
- PCB Dimension: 28 mm * 12 mm*10mm
Getting started with the Digital Temperature Humidity Sensor Module
In this tutorial, I’ll first go into a little background about humidity, then I’ll explain how the DHT11 measures humidity. After that, I’ll show you how to connect the DHT11 to an Arduino and give you some example code so you can use the DHT11 in your own projects.
Here are the ranges and accuracy of the DHT11:
- Humidity Range: 20-90% RH
- Humidity Accuracy: ±5% RH
- Temperature Range: 0-50 °C
- Temperature Accuracy: ±2% °C
- Operating Voltage: 3V to 5.5V
HOW THE DHT11 MEASURES HUMIDITY AND TEMPERATURE
The DHT11 detects water vapor by measuring the electrical resistance between two electrodes. The humidity sensing component is a moisture holding substrate with electrodes applied to the surface. When water vapor is absorbed by the substrate, ions are released by the substrate which increases the conductivity between the electrodes. The change in resistance between the two electrodes is proportional to the relative humidity. Higher relative humidity decreases the resistance between the electrodes, while lower relative humidity increases the resistance between the electrodes.
Connecting the Hardware
Connect the Digital Temperature Humidity Sensor to the arduino UNO as shown below.
Setting up the library
To read from the DHT sensor, we’ll use the DHT library from Adafruit. To use this library you also need to install the Adafruit Unified Sensor library.
Making the code and Upload it!
open the sample sketch that is located in file>examples>DHT sensor library>DHTtester. as shown below
Before to upload this code, Uncomment DHT11 type and comment DHT21 $ DHT22 type and upload it. As shown below
Open the serial monitor:
You should see the humidity and temperature readings displayed
Package includes: 1×DHT11 Temperature and Humidity sensor module