Grove Temperature & Humidity Sensor

This temperature & humidity sensor provides a pre-calibrated digital output

Hello World

Import programSeeed_Grove_Temp_Humidity_Example

Temp and Humidity sensor example. DHT11

Last commit 10 Mar 2015 by Seeed

Library

Import libraryDHT

Temp and Humidity sensor device driver.

Last commit 28 May 2016 by Components

Datasheet

http://www.seeedstudio.com/wiki/Grove-_Temperature_and_Humidity_Sensor

Notes

Features

  • Relative Humidity and temperature measurement
  • Full range temperature compensation Calibrated
  • Digital signal Long term stability
  • Long transmission distance
  • Low power consumption

Repository: Seeed_Grove_Temp_Humidity_Example

Introduction

This page covers the low cost DHT temperature & humidity sensors. These sensors are very basic and slow, but are great for some basic data logging. The DHT sensors are made of two parts, a capacitive humidity sensor and a thermistor. There is also a very basic chip inside that does some analog to digital conversion and spits out a digital signal with the temperature and humidity. The digital signal is fairly easy to read using any microcontroller.

Product Specifications

There are different versions of the DHT sensor, they look a bit similar and have the same pinout, but have different characteristics.

DHT11

  • Power Supply: 3 to 5V DC, 2.5mA max current use during conversion (while requesting data)
  • Operating range: 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)
  • Body size: 15.5mm x 12mm x 5.5mm

DHT22

  • 3 to 5V power and I/O 2.5mA max current use during conversion (while requesting data)
  • Good for 0-100% humidity readings with 2-5% accuracy
  • Good for -40 to 125°C temperature readings ±0.5°C accuracy
  • No more than 0.5 Hz sampling rate (once every 2 seconds)
  • Body size: 15.1mm x 25mm x 7.7mm

The DHT22 is a little more accurate. All sensors have a low sampling rate.

Different names

They come in different packages, breakoutboards:

Wiring / Connectivity

Connection of the SEN11301P or SEN51035P:

/media/uploads/Wimpie/_scaled_wiring.jpg

  • black - GND (Ground)
  • red - VCC (3 to 5V power)
  • white - NC (not connected)
  • yellow - SIG (Signal or data)

Connection of the DHT11 or DHT22:

Don't forget to place a 5K or 4k7 resistor between VCC and the data pin, to act as a medium-strength pull up on the data line.

/media/uploads/Wimpie/dht11_pinout.jpg

  • pin 1 - VCC (3 to 5V power)
  • pin 2 - Data
  • pin 3 - NC (not connected)
  • pin 4 - GND

Example