Description
The DHT11 is a basic, ultra low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed). Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old.
Features
3 to 5V power and I/O
2.5mA max current use during conversion (while requesting data)
Good for 20-80% humidity readings with 5% accuracy
Good for 0-50°C temperature readings ±2°C accuracy
No more than 1 Hz sampling rate (once every second)
Getting started Digital Temperature and Humidity Sensor
Connections
- First left pin: Arduino 3-5V power
- Second left pin: Arduino digital data input pin
- First right most pin: Ground.
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Technical details:
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Step1: Hardware required
For this tutorial you will need:
Step2: Connecting the hardware
The Circuit
The connections are pretty easy, see the image above with breadboard circuit schematic.
Step3: Making the code and Upload it!
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. Follow the next steps to install those libraries.
Open your Arduino IDE and go to Sketch > Include Library > Manage Libraries. The Library Manager should open.
Search for “DHT” on the Search box and install all the DHT library from Adafruit.
Before to upload this code, Uncomment DHT11 type and comment DHT21 & DHT22 type and upload it. As shown below
Testing codes
Open the serial monitor
Package includes: 1×DHT11 Temperature and Humidity sensor
