DHTxx Sensors @ The Adafruit Learning System:
This tutorial covers the low cost DHT temperature & humidity sensors. These sensors are very basic and slow, but are great for hobbyists who want to do 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.
DHTxx Sensors Tutorial - [Link]
Stephanie @ planetstephanie.net writes:
The red circle ‘red alert light’ is wired to the XBee’s RSSI so when the XBee receives a wireless command, the red light comes on for a few seconds.
The white gridded rectangle is the DHT22 sensor (temperature and humidity). I felt it would ‘blend in’ enough that it should be mounted right up front for all to see. The little black hole to the right of the DHT22 is for the light sensor.
Why is there a light sensor? Why not? Also: because I had an extra one laying around.
The screen display is mostly self-evident. Time, day, date. Heat/Cool. Run/Hold/Override. Target temp (small) and actual temp (large). Fan status (on/auto) and humidity.
Thermostat Three - [Link]
Andyx writes – [via]
This is a work in progress project which uses a Solar charging MintyBoost to power an Arduino with a Proto Screw Shield on it. Attached is a 2X16 LCD using the I2C Backpack, a DHT22 Temperature and Humidity Sensor, a Waterproof DS18B20 Sensor and a 5V analog PH Probe/Adapter.
Solar Minty + DHT22 + Waterproof DS18B20 + PH Probe - [Link]
RasterWeb! Logging the temperature and humidity… [via]
Last November one of the Arduino-based projects I started working on was a temperature logger for the office. With winter coming up I wanted to see just how cold it got. (The office is in a converted attic, and the heating and cooling leaves much to be desired.)
I picked up a TMP36 – Analog Temperature sensor and got it wired up and wrote some hacky perl code to read the data and log it. I never really got it out of the experimentation stage, and ended up pulling the Arduino out for another project. (Isn’t that often the case!?)
So last month when Adafruit came out with the DHT22 temperature-humidity sensor I figured I should grab one, and maybe I’d get around to finishing the project.
My temperature (and humidity!) logger is still not done, but I did whip up something to run this week while Wisconsin is having a heat wave. The office has a window air conditioning unit, but it only runs when someone is in the office. When no one is there, it gets hot. How hot? Well, now we know….
Logging the temperature and humidity - [Link]
This tutorial covers the low cost DHT temperature & humidity sensors. These sensors are very basic and slow, but are great for hobbyists who want to do 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. [via]
Sensor tutorials – DHT11/DHT21/DHT22 low cost temperature/humidity sensors – [Link]
























