Temperature-Humidity sensor : Tutorial Leave a comment

DHT22 (or AM2302) is a low cost high precision humidity and temperature sensor with a single wire digital interface.It utilizes exclusive digital signal collecting technique and humidity sensing technology and can ouptut calibrated digital signal. Small size & low consumption & long transmission distance (20 meters) enable AM2303 to be suited in all kinds of harsh applications.

Power voltage shoud be between 3.3V and 6V DC. When power is supplied to sensor don’t send any instruction to it withing one second to pass unstable status. One 100nF capacitor can be added between VDD and GND for wave filtering.

Features :

  • 3.3 – 6 V Input
  • 1-1.5 mA measuring current
  • 40-50 uA standby current
  • Humidity from 0 – 100 % RH
  • -40 – 80 degrees C temperature range
  • +- 2 % RH accuracy
  • +- 0.5 degrees C
  • 20 m max wire length

How to use :

You can use the DHT22 humidity/temperature sensor and the Arduino UNO board to read data and print it out to the serial monitor or to display it on an LCD. The videos below shows how to realize this application.


PART 1: Read air Temperature and Humidity from DHT22 sensor using Arduino board


PART 2: Display air Temperature and Humidity from DHT22 sensor using LCD display


In order to realize this project you will need the following components :

 

Development board

 OR 

 

DHT11 / DHT22 Sensors

 OR 

 

1 kohm pull-up Resistor

 

I2C Liquid Crystal Display

 

Mini Breadboard

 

Jumper wires


Resources :

Arduino sketch

DHT Arduino Library

LCD I2C Arduino Library

DHT22 datasheet

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