sunTimes.h

#include <Arduino.h>
#include <ArduinoJson.h>
#include <utilities/globals.h>
#include <utilities/networkSystem.h>
#include <utilities/fileSystem.h>
#include <utilities/timeSystem.h>
#include <HTTPClient.h>

#include <stdio.h>
#include <math.h>

#define SUN_TIMES_DEBUG true
#define GEO_RESP_SIZE 1500

/* A macro to compute the number of days elapsed since 2000 Jan 0.0 */
/* (which is equal to 1999 Dec 31, 0h UT)                           */

#define days_since_2000_Jan_0(y,m,d) \
    (367L*(y)-((7*((y)+(((m)+9)/12)))/4)+((275*(m))/9)+(d)-730530L)

/* Some conversion factors between radians and degrees */

#ifndef PI
 #define PI        3.1415926535897932384
#endif

#define RADEG     ( 180.0 / PI )
#define DEGRAD    ( PI / 180.0 )

/* The trigonometric functions in degrees */

#define sind(x)  sin((x)*DEGRAD)
#define cosd(x)  cos((x)*DEGRAD)
#define tand(x)  tan((x)*DEGRAD)

#define atand(x)    (RADEG*atan(x))
#define asind(x)    (RADEG*asin(x))
#define acosd(x)    (RADEG*acos(x))
#define atan2d(y,x) (RADEG*atan2(y,x))


/* Following are some macros around the "workhorse" function __daylen__ */
/* They mainly fill in the desired values for the reference altitude    */
/* below the horizon, and also selects whether this altitude should     */
/* refer to the Sun's center or its upper limb.                         */


/* This macro computes the length of the day, from sunrise to sunset. */
/* Sunrise/set is considered to occur when the Sun's upper limb is    */
/* 35 arc minutes below the horizon (this accounts for the refraction */
/* of the Earth's atmosphere).                                        */
#define day_length(year,month,day,lon,lat)  \
        __daylen__( year, month, day, lon, lat, -35.0/60.0, 1 )

/* This macro computes the length of the day, including civil twilight. */
/* Civil twilight starts/ends when the Sun's center is 6 degrees below  */
/* the horizon.                                                         */
#define day_civil_twilight_length(year,month,day,lon,lat)  \
        __daylen__( year, month, day, lon, lat, -6.0, 0 )

/* This macro computes the length of the day, incl. nautical twilight.  */
/* Nautical twilight starts/ends when the Sun's center is 12 degrees    */
/* below the horizon.                                                   */
#define day_nautical_twilight_length(year,month,day,lon,lat)  \
        __daylen__( year, month, day, lon, lat, -12.0, 0 )

/* This macro computes the length of the day, incl. astronomical twilight. */
/* Astronomical twilight starts/ends when the Sun's center is 18 degrees   */
/* below the horizon.                                                      */
#define day_astronomical_twilight_length(year,month,day,lon,lat)  \
        __daylen__( year, month, day, lon, lat, -18.0, 0 )


/* This macro computes times for sunrise/sunset.                      */
/* Sunrise/set is considered to occur when the Sun's upper limb is    */
/* 35 arc minutes below the horizon (this accounts for the refraction */
/* of the Earth's atmosphere).                                        */
#define sun_rise_set(year,month,day,lon,lat,rise,set)  \
        __sunriset__( year, month, day, lon, lat, -35.0/60.0, 1, rise, set )

/* This macro computes the start and end times of civil twilight.       */
/* Civil twilight starts/ends when the Sun's center is 6 degrees below  */
/* the horizon.                                                         */
#define civil_twilight(year,month,day,lon,lat,start,end)  \
        __sunriset__( year, month, day, lon, lat, -6.0, 0, start, end )

/* This macro computes the start and end times of nautical twilight.    */
/* Nautical twilight starts/ends when the Sun's center is 12 degrees    */
/* below the horizon.                                                   */
#define nautical_twilight(year,month,day,lon,lat,start,end)  \
        __sunriset__( year, month, day, lon, lat, -12.0, 0, start, end )

/* This macro computes the start and end times of astronomical twilight.   */
/* Astronomical twilight starts/ends when the Sun's center is 18 degrees   */
/* below the horizon.                                                      */
#define astronomical_twilight(year,month,day,lon,lat,start,end)  \
        __sunriset__( year, month, day, lon, lat, -18.0, 0, start, end )

class sunTimes {
    private:
        const char* ipStackURL = "http://api.ipstack.com/check?access_key=0f4ce7d93a2ed67e7435d4227cc0e931&fields=main";

        boolean gotGeoData = false;

        double degToRad(double angleDeg);
        double radToDeg(double angleRad);
        double calcMeanObliquityOfEcliptic(double t);
        double calcGeomMeanLongSun(double t);
        double calcObliquityCorrection(double t);
        double calcEccentricityEarthOrbit(double t);
        double calcGeomMeanAnomalySun(double t);
        double calcEquationOfTime(double t);
        double calcTimeJulianCent(double jd);
        double calcSunTrueLong(double t);
        double calcSunApparentLong(double t);
        double calcSunDeclination(double t);
        double calcHourAngleSunrise(double lat, double solarDec);
        double calcHourAngleSunset(double lat, double solarDec);
        double calcJD(int year, int month, int day);
        double calcJDFromJulianCent(double t);
        double calcSunEqOfCenter(double t);
        double calcSunriseUTC(double JD, double latitude, double longitude);
        double calcSunsetUTC(double JD, double latitude, double longitude);

        /* New Function prototypes */
        double __daylen__( int year, int month, int day, double lon, double lat,
                        double altit, int upper_limb );
        int __sunriset__( int year, int month, int day, double lon, double lat,
                        double altit, int upper_limb, double *rise, double *set );
        void sunpos( double d, double *lon, double *r );
        void sun_RA_dec( double d, double *RA, double *dec, double *r );
        double revolution( double x );
        double rev180( double x );
        double GMST0( double d );

    public:
        void getGeoData();
        void calcSunTimes();
        void calcNewSunTimes();
};