Reducing Size

system · August 2, 2011, 5:07am

I am making a timer that is programmed with the sunrise/sunset times for my city and I am making Arduino use a relay to control some mains lighting. I am using a chronodot to keep time. I have it working, the only problem is that it is too large. My programming skills are basic and I’m sure there is a better way to do this. Below is my code. The current size is 41000 bytes and I need to put it on a Duemilanove so down to 32000 bytes (I think).

#include <Wire.h>
#include "Chronodot.h"
Chronodot RTC;

int LightOff[367] = {0, 930, 930, 930, 929, 929, 929, 928, 928, 927, 927, 926, 925, 925, 924, 923, 922, 921, 20, 919, 918, 917, 916, 915, 913, 912, 911, 909, 908, 906, 905, 903, 902, 900, 859, 857, 855, 854, 852, 850, 848, 846, 845, 843, 841, 839, 837, 835, 833, 831, 829, 827, 825, 823, 820, 818, 816, 814, 812, 810, 809, 808, 805, 803, 801, 759, 756, 754, 752, 750, 747, 745, 743, 741, 738, 736, 734, 731, 729, 727, 724, 722, 720, 717, 715, 713, 710, 708, 706, 703, 701, 659, 656, 654, 652, 650, 647, 645, 643, 640, 638, 636, 634, 631, 629, 627, 625, 623, 620, 618, 616, 614, 612, 610, 608, 607, 606, 601, 559, 557, 555, 553, 552, 550, 548, 546, 544, 542, 540, 539, 537, 535, 534, 532, 530, 529, 527, 526, 524, 523, 521, 520, 519, 517, 516, 515, 514, 513, 512, 510, 509, 509, 508, 507, 506, 505, 505, 504, 503, 503, 502, 502, 501, 501, 501, 500, 500, 500, 500, 500, 500, 500, 500, 500, 501, 501, 501, 502, 502, 503, 503, 504, 504, 505, 506, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 519, 520, 521, 522, 524, 525, 526, 528, 529, 530, 532, 533, 535, 536, 538, 539, 541, 542, 544, 546, 547, 549, 550, 552, 553, 555, 557, 558, 600, 602, 603, 605, 606, 608, 610, 611, 613, 615, 616, 618, 619, 621, 623, 624, 626, 628, 629, 631, 633, 634, 636, 638, 639, 641, 642, 644, 646, 647, 649, 651, 652, 654, 656, 657, 659, 700, 702, 704, 705, 707, 709, 710, 712, 714, 715, 717, 719, 720, 722, 724, 725, 727, 729, 730, 732, 734, 736, 737, 739, 741, 742, 744, 746, 748, 749, 751, 753, 755, 757, 758, 800, 802, 804, 805, 807, 809, 811, 813, 815, 816, 818, 820, 822, 824, 825, 827, 829, 831, 833, 834, 836, 838, 840, 841, 843, 845, 847, 848, 850, 852, 853, 855, 857, 858, 900, 901, 903, 904, 906, 907, 909, 910, 912, 913, 914, 915, 916, 918, 919, 920, 921, 922, 923, 924, 924, 925, 926, 927, 927, 928, 928, 929, 929, 929, 930, 930, 930, 930, 930, 930};
int LightOn[367] ={0, 1650, 1651, 1652, 1653, 1654, 1656, 1657, 1658, 1700, 1701, 1703, 1704, 1706, 1707, 1709, 1710, 1712, 1714, 1715, 1717, 1719, 1721, 1722, 1724, 1726, 1728, 1729, 1731, 1733, 1735, 1737, 1739, 1740, 1742, 1744, 1746, 1748, 1750, 1752, 1754, 1755, 1757, 1759, 1801, 1803, 1805, 1807, 1809, 1810, 1812, 1814, 1816, 1818, 1820, 1822, 1823, 1825, 1827, 1829, 1830, 1831, 1832, 1834, 1836, 1838, 1840, 1841, 1843, 1845, 1847, 1849, 1850, 1852, 1854, 1856, 1857, 1859, 1901, 1903, 1904, 1906, 1908, 1910, 1911, 1913, 1915, 1916, 1918, 1920, 1922, 1923, 1925, 1927, 1929, 1930, 1932, 1934, 1935, 1937, 1939, 1941, 1942, 1944, 1946, 1947, 1949, 1951, 1953, 1954, 1956, 1958, 1959, 2001, 2003, 2005, 2006, 2008, 2010, 2011, 2013, 2015, 2016, 2018, 2020, 2021, 2023, 2025, 2026, 2028, 2030, 2031, 2033, 2035, 2036, 2038, 2039, 2041, 2042, 2044, 2045, 2047, 2048, 2050, 2051, 2052, 2054, 2055, 2056, 2057, 2059, 2100, 2101, 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2109, 2110, 2111, 2111, 2112, 2113, 2113, 2114, 2114, 2115, 2115, 2115, 2116, 2116, 2116, 2116, 2116, 2116, 2116, 2116, 2116, 2116, 2115, 2115, 2115, 2114, 2114, 2113, 2113, 2112, 2111, 2111, 2110, 2109, 2108, 2107, 2106, 2105, 2104, 2103, 2102, 2101, 2100, 2058, 2057, 2056, 2054, 2053, 2051, 2050, 2048, 2047, 2045, 2044, 2042, 2040, 2038, 2037, 2035, 2033, 2031, 2029, 2028, 2026, 2024, 2022, 2020, 2018, 2016, 2014, 2012, 2010, 2007, 2005, 2003, 2001, 1959, 1957, 1955, 1952, 1950, 1948, 1946, 1943, 1941, 1939, 1937, 1934, 1932, 1930, 1927, 1925, 1923, 1921, 1918, 1916, 1914, 1911, 1909, 1906, 1904, 1902, 1859, 1857, 1855, 1852, 1850, 1847, 1845, 1843, 1841, 1838, 1836, 1834, 1831, 1829, 1827, 1824, 1822, 1820, 1818, 1815, 1813, 1811, 1808, 1806, 1804, 1802, 1800, 1758, 1755, 1753, 1751, 1749, 1747, 1745, 1742, 1740, 1738, 1736, 1734, 1732, 1730, 1728, 1727, 1725, 1723, 1721, 1719, 1717, 1716, 1714, 1712, 1711, 1709, 1707, 1706, 1704, 1703, 1701, 1700, 1658, 1657, 1656, 1654, 1653, 1652, 1651, 1650, 1649, 1648, 1647, 1646, 1645, 1644, 1644, 1643, 1642, 1642, 1641, 1641, 1640, 1640, 1640, 1639, 1639, 1639, 1639, 1639, 1639, 1639, 1639, 1640, 1640, 1640, 1641, 1641, 1642, 1642, 1643, 1643, 1644, 1645, 1646, 1647, 1648, 1649};

int Relay = 7; // Relay on Pin 7
int DayCode = 0;
int Year = 0;
int Month = 0;
int Day = 0;
int Hour = 0;
int Minute = 0;
int Second = 0;
int Multiplier = 0;
int Time = 0;

// ------------------------------------------

void setup() {
  
  pinMode(Relay, OUTPUT);
  
  Serial.begin(9600);
  Wire.begin();
  RTC.begin();
  
}

// -------------------------------------------

void loop() {
  
  DateTime now = RTC.now();    // Retrieve all information from ChronoDot
  Year = now.year();
  Month = now.month();
  Day = now.day();
  Hour = now.hour();
  Minute = now.minute();
  Second = now.second();
  
  if (Month == 1)  {      //Create the multiplier which is added to the day to obtain the date code
    Multiplier = 0;  }
  if (Month == 2)  {
    Multiplier = 31;  }
  if (Month == 3)  {
    Multiplier = 60;  }
  if (Month == 4)  {
    Multiplier = 91;  }
  if (Month == 5)  {
    Multiplier = 121;  }
  if (Month == 6)  {
    Multiplier = 152;  }
  if (Month == 7)  {
    Multiplier = 182;  }
  if (Month == 8)  {
    Multiplier = 213;  }
  if (Month == 9)  {
    Multiplier = 244;  }
  if (Month == 10)  {
    Multiplier = 274;  }
  if (Month == 11)  {
    Multiplier = 305;  }
  if (Month == 12)  {
    Multiplier = 335;  }
  
  DayCode = Multiplier + Day;  // Determine what day it is
  Time = Hour*100 + Minute;
  
  // Perform Calculations to turn relay on/off
  if (DayCode == 1)  {
    if (Time == LightOff[DayCode])  {
      digitalWrite(Relay, LOW);  }
    if (Time == LightOn[DayCode])  {
      digitalWrite(Relay, HIGH);  }
  }
  if (DayCode == 2)  {
    if (Time == LightOff[DayCode])  {
      digitalWrite(Relay, LOW);  }
    if (Time == LightOn[DayCode])  {
      digitalWrite(Relay, HIGH);  }
  }
}
....
....
....
etc for the rest of the days

I know I need to parse down my hundreds of if statements but am unsure on what statement to use.

Thanks for helping a first time Arduino user,
Spencer

ManicDee · August 2, 2011, 5:55am

You have set up a (huge) array with the times for turning things on and off.

Then you have a long series of if-statements to check what day it is, then retrieve that day's values from the array.

One simple thing you can do is remove the if-statements, since you're needlessly repeating that piece of code:

  // Perform Calculations to turn relay on/off
  if (DayCode == 1)  {
    if (Time == LightOff[DayCode])  {
      digitalWrite(Relay, LOW);  }
    if (Time == LightOn[DayCode])  {
      digitalWrite(Relay, HIGH);  }
  }
  if (DayCode == 2)  {
    if (Time == LightOff[DayCode])  {
      digitalWrite(Relay, LOW);  }
    if (Time == LightOn[DayCode])  {
      digitalWrite(Relay, HIGH);  }
  }

You can replace all of those with just the two if statements on their own:

    if (Time == LightOff[DayCode])  {
      digitalWrite(Relay, LOW);  }
    if (Time == LightOn[DayCode])  {
      digitalWrite(Relay, HIGH);  }

You could also replace the "multiplier" (which is really an "offset") with an array:

int multiplier [12] = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 }
…
DayCode = Day + multiplier[ Month - 1 ]; // Array indexes start at 0, so multiplier is 0…11

And then, there's the issue of what are those times representing? If they are sunrise/sunset times you'll find that there are discussions on the old forums about calculating the times. Search for arduino chicken-coop

nickgammon · August 2, 2011, 7:52am

I adapted some code I found some years ago to run on the Arduino. With some minor modifications it should suit you:

#define HOME_LATITUDE -37.12345   
#define HOME_LONGITUDE 145.6789   
#define UTC_OFFSET 10               // 10 hours east of UTC

/*****************************************************
 *This is an implementation of the Sunrise/Sunset Algorithm
 *found at 
 * http://williams.best.vwh.net/sunrise_sunset_algorithm.htm
 *from the Almanac for Computers, 1990
 *Published by Nautical Almanac Office
 *Washington, DC 20392
 *Implemented by Chris Snyder
 *****************************************************/

#define OFFICIAL_ZENITH 90.83333
#define CIVIL_ZENITH 96
#define NAUTICAL_ZENITH 102
#define ASTRONOMICAL_ZENITH 108

/*****************************************************
 *Function name:calcSunset
 *Params: $date(The day to calculate sunset or sunrise for)
 *	$lat(The latitude for the location to calculate sunrise or sunset for)
 *	$lon(The longitude for the location to calculate sunrise or sunset for west is negative)
 *	$sunset(if set to 1 calculates sunset if set to 0 sunrise)
 *	$GMToffset(difference in hours from GMT)
 * 
 * 	$zenith:                Sun's zenith for sunrise/sunset
 * 	  offical      = 90 degrees 50'  (90.8333)
 * 	  civil        = 96 degrees
 * 	  nautical     = 102 degrees
 * 	  astronomical = 108 degrees
 * 	
 * 	NOTE: longitude is positive for East and negative for West
 * 	      latitude is positive for North and negative for south
 * 	
 *****************************************************/

#define pi 3.14159265358979323

float AdjustTo360 (float i)
{
  if (i > 360.0)
    i -= 360.0;
  else if (i < 0.0)
    i += 360.0;  
  return i;
} // end of AdjustTo360

float AdjustTo24 (float i)
{
  if (i > 24.0)
    i -= 24.0;
  else if (i < 0.0)
    i += 24.0;  
  return i;
} // end of AdjustTo24

float deg2rad (float degrees)
{
  return degrees * pi / 180;
}  // end of deg2rad


float rad2deg (float radians)
{
  return radians / ( pi / 180 );
}  // end of rad2deg

void calcSunset(int n, float lat, float lon, bool sunset, float GMToffset, float zenith, 
                byte & hour, byte & minutes)
{

  hour = minutes = 0;

  //Convert the longitude to hour value and calculate and
  //Approximate time.
  float lonhour = (lon/15);
  float t, m;

  if(sunset)
    t=n+((18 - lonhour)/24);
  else
    t=n+((6 - lonhour)/24);

  //Calculate the Sun's mean anomaly
  m = (0.9856*t) - 3.289;

  //Calculate the Sun's true longitude
  float sinm = sin(deg2rad(m));
  float sin2m = sin(2*deg2rad(m));

  float l= AdjustTo360 (m +(1.916 * sinm) + (0.02 * sin2m) + 282.634);

  //Calculate the Sun's right ascension(RA)
  float tanl = 0.91764 * tan(deg2rad(l));
  float ra = AdjustTo360 (rad2deg(atan(tanl)));

  //Putting the RA value into the same quadrant as L
  float lq = (floor(l/90)) * 90;
  float raq = (floor(ra/90)) * 90;
  ra = ra + (lq - raq);

  //Convert RA values to hours
  ra /= 15;

  //calculate the Sun's declination
  float sindec = 0.39782 * sin(deg2rad(l));
  float cosdec = cos(asin(sindec));

  //calculate the Sun's local hour angle
  float cosh = (cos(deg2rad(zenith)) - (sindec * sin(deg2rad(lat)))) 
    / (cosdec * cos(deg2rad(lat)));

  //if cosH > 1 the sun never rises on this date at this location
  //if cosH < -1 the sun never sets on this date at this location

  if (cosh >  1)
    return; 
  else if (cosh < -1)
    return;

  float h;

  //finish calculating H and convert into hours
  if(sunset)
    h = rad2deg(acos(cosh));
  else
    h = 360 - rad2deg(acos(cosh));

  h /= 15;

  //Calculate local mean time of rising/setting
  t = h + ra - (0.06571 * t) - 6.622;

  //Adjust back to UTC
  float ut = AdjustTo24 (t - lonhour);
  //Adjust for current time zone
  ut= AdjustTo24 (ut+GMToffset);

  hour = floor(ut);
  minutes = round(60*(ut - hour));

}  // end of calcSunset

int days [] = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 };

int dayNumber (int year, int month, int day)
  {
  int extra = 0;
  
  if (floor (year % 4) == 0 && month > 2)
    extra = 1;
    
  return days [month - 1] + day + extra - 1;
        
  }  // end of dayNumber


void setup ()
{
  Serial.begin (115200);
  
  byte hour, minutes;
  
  int day = dayNumber (2011, 8, 2);   // year, month, day
  
  Serial.print ("day is ");
  Serial.println (day, DEC);
  
  calcSunset (day, HOME_LATITUDE, HOME_LONGITUDE, false, UTC_OFFSET, OFFICIAL_ZENITH,  hour, minutes);
  
  Serial.print ("Sunrise at: ");
  Serial.print (hour, DEC);
  Serial.print (":");
  Serial.print (minutes, DEC);
  Serial.println ();

  calcSunset (day, HOME_LATITUDE, HOME_LONGITUDE, true, UTC_OFFSET, OFFICIAL_ZENITH,  hour, minutes);

  Serial.print ("Sunset at: ");
  Serial.print (hour, DEC);
  Serial.print (":");
  Serial.print (minutes, DEC);
  Serial.println ();
  
}  // end of setup

void loop ()
{
}

You need to replace a couple of things:

The hard-coded date (2011/8/2) would be replaced by the output from the clock chip
Change the first three lines to reflect your latitude, longitude and UTC time offset
If you change OFFICIAL_ZENITH to CIVIL_ZENITH (where the function is called) you get Dawn and Dusk rather than Sunrise and Sunset.

Having done that the code should give you the sunrise/sunset times (as illustrated by the debugging prints) and you could use that to work out whether to turn your lights on or not.

Example output when I tested:

day is 214
Sunrise at: 7:16
Sunset at: 17:32

This is correct for where I am.

Code size:

Binary sketch size: 6414 bytes (of a 32256 byte maximum)

utopia · August 3, 2011, 1:13am

OK, so now I (and possibly others) are waiting to hear - did these changes fix your memory problem, or do you need still more tweaking? If so, please post your latest code and we can hack at it...

system · August 3, 2011, 5:04am

You can replace all of those with just the two if statements on their own:
    if (Time == LightOff[DayCode])  {

digitalWrite(Relay, LOW); }
if (Time == LightOn[DayCode]) {
digitalWrite(Relay, HIGH); }

This was the one. I definitely overlooked this one. I replaced 2200 lines of code with these 4. It saved 32kb. I feel a little stupid now.

I really appreciate the help and the eagerness to find out the results (I'm a busy man lol at least give me 24 hours to update it). Super duper forum. Thanks tons.

Spencer

system · May 5, 2021, 7:34pm