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ESP8266 Home Automation Projects by Catalin Batrinu

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Temperature sensor

There are a lot of temperature sensors that can be used, but for this project we will use a very common one, the DTH22. It can measure temperature and humidity.

The following are the DHT22 characteristics:

  • Low cost
  • 3 to 5V power and I/O
  • 5mA max current used 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 two seconds)
  • Body size 15.1mm x 25mm x 7.7mm
  • 4 pins with 0.1" spacing

DHT22 can be found as a separate sensor or as a breakout. It is preferrable to buy the breakout version since it has also the pull-up 4k7 resistor and a capacitor. If you prefer the sensor alone this ...

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