DHT11 (C version)ΒΆ

../../_images/dht11.jpg

The foglamp-south-dht plugin implements a temperature and humidity sensor using the DHT11 sensor module. Two versions of plugins for the DHT11 are available and are used as the example for plugin development. The other DHT11 plugin is foglamp-south-dht11 and is a Python version.

The DHT11 and the associated DHT22 sensors may be used, however they have slightly different characteristics;

  DHT11 DHT22
Voltage 3 to 5 Volts 3 to 5 Volts
Current 2.5mA 2.5mA
Humidity Range 0-50 % humidity 5% accuracy 0-100% humidity 2.5% accuracy
Temperature Range 0-50 +/- 2 degrees C -40 to 80 +/- 0.5 degrees C
Sampling Frequency 1Hz 0.5Hz

Note

Due to the requirement for attaching to GPIO pins this plugin is only available for the Raspberry Pi platform.

To create a south service with the DHT11 plugin

  • Click on South in the left hand menu bar
  • Select dht11_V2 from the plugin list
  • Name your service and click Next
dht11_1
  • Configure the plugin
    • Asset Name: The asset name which will be used for all data read.
    • Rpi Pin: The GPIO pin on the Raspberry Pi to which the DHT11 serial pin is connected.
  • Click Next
  • Enable the service and click on Done