Merge pull request wled#3406 from Aircoookie/sunset_accuracy_fix

fix for wled#3400 - wrong sunset time 00:00

Author: softhack007

platformio.ini

@@ -352,6 +352,7 @@ platform_packages = ${common.platform_packages}
 board_build.ldscript = ${common.ldscript_1m128k}
 build_unflags = ${common.build_unflags}
 build_flags = ${common.build_flags_esp8266} -D WLED_RELEASE_NAME=ESP01 -D WLED_DISABLE_OTA
+  ; -D WLED_USE_UNREAL_MATH ;; may cause wrong sunset/sunrise times, but saves 7064 bytes FLASH and 975 bytes RAM
 lib_deps = ${esp8266.lib_deps}
 
 [env:esp07]
@@ -605,6 +606,7 @@ build_flags = ${common.build_flags} ${esp32s2.build_flags} -D WLED_RELEASE_NAME=
   -DARDUINO_USB_DFU_ON_BOOT=0
   -DLOLIN_WIFI_FIX ; seems to work much better with this
   -D WLED_USE_PSRAM
+  ; -D WLED_USE_UNREAL_MATH ;; may cause wrong sunset/sunrise times, but saves 6792 bytes FLASH
   -D WLED_WATCHDOG_TIMEOUT=0
   -D CONFIG_ASYNC_TCP_USE_WDT=0
   -D LEDPIN=16

wled00/ntp.cpp

@@ -2,6 +2,21 @@
 #include "wled.h"
 #include "fcn_declare.h"
 
+// on esp8266, building with `-D WLED_USE_UNREAL_MATH` saves around 7Kb flash and 1KB RAM
+//  warning: causes errors in sunset calculations, see #3400
+#if defined(WLED_USE_UNREAL_MATH)
+#define sinf sin_t
+#define asinf asin_t
+#define cosf cos_t
+#define acosf acos_t
+#define tanf tan_t
+#define atanf atan_t
+#define fmodf fmod_t
+#define floorf floor_t
+#else
+#include <math.h>
+#endif
+
 /*
  * Acquires time from NTP server
  */
@@ -412,8 +427,8 @@ int getSunriseUTC(int year, int month, int day, float lat, float lon, bool sunse
   //1. first calculate the day of the year
   float N1 = 275 * month / 9;
   float N2 = (month + 9) / 12;
-  float N3 = (1 + floor_t((year - 4 * floor_t(year / 4) + 2) / 3));
-  float N = N1 - (N2 * N3) + day - 30;
+  float N3 = (1.0f + floorf((year - 4 * floorf(year / 4) + 2.0f) / 3.0f));
+  float N = N1 - (N2 * N3) + day - 30.0f;
 
   //2. convert the longitude to hour value and calculate an approximate time
   float lngHour = lon / 15.0f;
@@ -423,37 +438,37 @@ int getSunriseUTC(int year, int month, int day, float lat, float lon, bool sunse
   float M = (0.9856f * t) - 3.289f;
 
   //4. calculate the Sun's true longitude
-  float L = fmod_t(M + (1.916f * sin_t(DEG_TO_RAD*M)) + (0.02f * sin_t(2*DEG_TO_RAD*M)) + 282.634f, 360.0f);
+  float L = fmodf(M + (1.916f * sinf(DEG_TO_RAD*M)) + (0.02f * sinf(2*DEG_TO_RAD*M)) + 282.634f, 360.0f);
 
   //5a. calculate the Sun's right ascension
-  float RA = fmod_t(RAD_TO_DEG*atan_t(0.91764f * tan_t(DEG_TO_RAD*L)), 360.0f);
+  float RA = fmodf(RAD_TO_DEG*atanf(0.91764f * tanf(DEG_TO_RAD*L)), 360.0f);
 
   //5b. right ascension value needs to be in the same quadrant as L
-  float Lquadrant  = floor_t( L/90) * 90;
-  float RAquadrant = floor_t(RA/90) * 90;
+  float Lquadrant  = floorf( L/90) * 90;
+  float RAquadrant = floorf(RA/90) * 90;
   RA = RA + (Lquadrant - RAquadrant);
 
   //5c. right ascension value needs to be converted into hours
   RA /= 15.0f;
 
   //6. calculate the Sun's declination
-  float sinDec = 0.39782f * sin_t(DEG_TO_RAD*L);
-  float cosDec = cos_t(asin_t(sinDec));
+  float sinDec = 0.39782f * sinf(DEG_TO_RAD*L);
+  float cosDec = cosf(asinf(sinDec));
 
   //7a. calculate the Sun's local hour angle
-  float cosH = (sin_t(DEG_TO_RAD*ZENITH) - (sinDec * sin_t(DEG_TO_RAD*lat))) / (cosDec * cos_t(DEG_TO_RAD*lat));
-  if (cosH > 1 && !sunset) return 0;  // the sun never rises on this location (on the specified date)
-  if (cosH < -1 && sunset) return 0;  // the sun never sets on this location (on the specified date)
+  float cosH = (sinf(DEG_TO_RAD*ZENITH) - (sinDec * sinf(DEG_TO_RAD*lat))) / (cosDec * cosf(DEG_TO_RAD*lat));
+  if ((cosH > 1.0f) && !sunset) return 0;  // the sun never rises on this location (on the specified date)
+  if ((cosH < -1.0f) && sunset) return 0;  // the sun never sets on this location (on the specified date)
 
   //7b. finish calculating H and convert into hours
-  float H = sunset ? RAD_TO_DEG*acos_t(cosH) : 360 - RAD_TO_DEG*acos_t(cosH);
+  float H = sunset ? RAD_TO_DEG*acosf(cosH) : 360 - RAD_TO_DEG*acosf(cosH);
   H /= 15.0f;
 
   //8. calculate local mean time of rising/setting
   float T = H + RA - (0.06571f * t) - 6.622f;
 
   //9. adjust back to UTC
-  float UT = fmod_t(T - lngHour, 24.0f);
+  float UT = fmodf(T - lngHour, 24.0f);
 
   // return in minutes from midnight
 	return UT*60;