DHT11 Temperature and Humidity Sensor Interfacing

 

DHT11 is a low cost Temperature and Humidity sensor which can be used for less precise application, but has a decent range of operation and sensing. Also no external calibration is required, as it has inbuilt calibration done in production laboratories, also it require minimal external components for interfacing.

 

Elementz_DHT11_bbThe above figure shows the Arduino interfacing with DHT11 library available from here. Arduino projects can be downloaded for testing and quick prototyping from our GitHub channel.

The greatest advantage of using this sensor is that it is capable of measuring accurately even if the host controller is 20 meters away from the sensor. The distance can be increased further by reducing the pull-up resistor value.

Features:

  • Chip: DHT11 temperature and humidity sensor
  • Ultra low cost
  • 3 to 5V power and I/O
  • 2.5mA max current use during conversion (while requesting data)
  • No more than 1 Hz sampling rate (once every second)

Parameter:

  • Humidity measuring range: 20-90% RH
  • Humidity accuracy: ± 5% RH
  • Temperature measuring range: 0-60°c
  • Temperature measurement accuracy: ± 2°c
  • Digital signal output
  • 4 pins with 0.1″ or 2.54mm spacing

 

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2 thoughts on “DHT11 Temperature and Humidity Sensor Interfacing

  1. Is there any documents related to calibration available? or how to calibrate if needed?
    I want to make a project for stability chamber in which I want to connect Sim900 module and DHT to arduino board. I want arduino to make a call/sms to me when the temperature and / or humidity goes out of range. The temperature and humidity is set and maintained using digital temperature and humidity controller for the stability chamber. It is 30 +/- 2C and 65% +/- 5%. Is it possible?

    • Dht11 is not an industrial grade sensor. It outputs digital value, so you need to calibrate in the software. You may find the sample code helpful for getting started. However, You can experiment with it in the real field.

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