CMake added *.c* wildcard to compile extern c files; Added calculation for absoluteHumidity

This commit is contained in:
2017-09-15 22:45:32 +02:00
parent 7a4d08ea3c
commit 4ef189b9dd
4 changed files with 98 additions and 3 deletions

View File

@@ -0,0 +1,80 @@
#include <stdio.h>
#include <stdlib.h>
#include <math.h> /* link against math lib */
#include "calculate.h"
#define R 8314.3 //J/(kmol*K) (universelle Gaskonstante)
#define mw 18.016 //kg/kmol (Molekulargewicht des Wasserdampfes)
/*
Bezeichnungen:
r = relative Luftfeuchte
T = Temperatur in °C
TK = Temperatur in Kelvin (TK = T + 273.15)
TD = Taupunkttemperatur in °C
DD = Dampfdruck in hPa
SDD = Sättigungsdampfdruck in hPa
Parameter:
a = 7.5, b = 237.3 für T >= 0
a = 7.6, b = 240.7 für T < 0 über Wasser (Taupunkt)
a = 9.5, b = 265.5 für T < 0 über Eis (Frostpunkt)
R* = 8314.3 J/(kmol*K) (universelle Gaskonstante)
mw = 18.016 kg/kmol (Molekulargewicht des Wasserdampfes)
AF = absolute Feuchte in g Wasserdampf pro m3 Luft
Formeln:
SDD(T) = 6.1078 * 10^((a*T)/(b+T))
DD(r,T) = r/100 * SDD(T)
r(T,TD) = 100 * SDD(TD) / SDD(T)
TD(r,T) = b*v/(a-v) mit v(r,T) = log10(DD(r,T)/6.1078)
AF(r,TK) = 10^5 * mw/R* * DD(r,T)/TK; AF(TD,TK) = 10^5 * mw/R* * SDD(TD)/TK
*/
static float sdd(float temperature) {
//select constant based on input temperature
float a = 7.5, b = 237.3;
if (temperature >= 0) {
a = 7.6;
b = 240.7;
}
return 6.1078 * pow(10, (a * temperature) / (b + temperature));
}
static float dd(float relativeHumidity, float temperature) {
return relativeHumidity / 100 * sdd(temperature);
}
/* CURRENTLY UNUSED
static float r(float temperature, float dewTemperature) {
// This is optional. Necessary with dew point measurements.
return 100 * sdd(dewTemperature) / sdd(temperature);
}
static float v(float relativeHumidity, float temperature) {
log10(dd(relativeHumidity, temperature)/6.1078);
}
static float td(float relativeHumidity, float temperature) {
//select constant based on input temperature
float a = 7.5, b = 237.3;
if (temperature >= 0) {
a = 7.6;
b = 240.7;
}
return b * v(relativeHumidity, temperature) / (a - v(relativeHumidity, temperature));
}
*/
static float af(float relativeHumidity, float temperature) {
float tk = temperature + 273.15;
return pow(10, 5) * mw/R * dd(relativeHumidity, temperature) / tk;
}
float absoluteHumidityFloat(float temperature, float humidity) {
return af(humidity, temperature);
}

View File

@@ -0,0 +1,15 @@
#ifndef calculate_H
#define calculate_H
#ifdef __cplusplus
extern "C"
{
#endif
float absoluteHumidityFloat(float temperature, float humidity);
#ifdef __cplusplus
}
#endif
#endif

View File

@@ -2,7 +2,7 @@
// For more information, please visit: https://github.com/loentar/ngrest
#include "humidityserver.h"
#include "calculate.h"
/*std::string humidityserver::echo(const std::string& text)
{
return "Hi, " + text;
@@ -10,5 +10,5 @@
float humidityserver::absolutehumidity(float temperature, float humidity) {
return temperature + humidity;
return absoluteHumidityFloat(temperature, humidity);
}