DHT-sensor-library
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Adding a simple Dew Point function to Adafruit DHT library
Hi. I am an astronomer/astrophotographer. I am currently building a control board for my Celestron telescope and one of the metrics I want to collect is the Dew Point. I will use this in deciding the power level I will supply to my Dew Heater on the telescope. I have found a simple Dew Point calculation, which would be great to be able to reference from a DHT sensor. The calculation can be found at https://iridl.ldeo.columbia.edu/dochelp/QA/Basic/dewpoint.html.
Would this be something that you would consider adding to the current library? I have provided my code below for your reference. This was tested on the following:
- Arduino board: *ARDUINO/UNO R3
- Arduino IDE version (found in Arduino -> About Arduino menu): 1.8.19
- Adafruit DHT11 and DHT22 sensors
DHT.h float computeDewPointSimple(float temperature, float percentHumidity, bool isFahrenheit = true);
DHT.cpp /*!
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@brief Compute Dew Point - Simple Method
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Using formula was proposed in a 2005 article by Mark G. Lawrence in the Bulletin of the American Meteorological Society:
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(https://iridl.ldeo.columbia.edu/dochelp/QA/Basic/dewpoint.html)
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@param temperature
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temperature in selected scale
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@param percentHumidity
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humidity in percent
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@param isFahrenheit
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true if fahrenheit, false if celcius
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@return float dew point */ float DHT::computeDewPointSimple(float temperature, float percentHumidity, bool isFahrenheit) {
float hi;
if (!isFahrenheit) temperature = convertCtoF(temperature);
hi = temperature-((100 - percentHumidity) / 5);
return isFahrenheit ? hi : convertFtoC(hi);
}
There is a more complex function that gives greater accuracy, which is detailed on the web page provided above, but I have yet compiled that function.
Kind regards Teddy