Adding a simple Dew Point function to Adafruit DHT library #216
Description
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
/*!
-
@brief Compute Dew Point - Simple Method
-
Using formula was proposed in a 2005 article by Mark G. Lawrence in the Bulletin of the American Meteorological Society: -
(https://iridl.ldeo.columbia.edu/dochelp/QA/Basic/dewpoint.html) -
@param temperature
-
temperature in selected scale -
@param percentHumidity
-
humidity in percent -
@param isFahrenheit
-
true if fahrenheit, false if celcius -
@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