Code Optimiztion

Using Arduino Project Guidance
#1

Hi guys I currently have a project for an automated high power led lighting system which has 4 channels controlled using pwm and an rtc clock.

My issue is that this is my first time using an arduino for such a major thing and rtc. I do have a basic code layout but i need to optimize it since it is using up 95% of the memory so i was wondering if someone could help me improve it.

#include <Wire.h>
#include "Sodaq_DS3231.h"
//declare times and corresponding led brightness
const char* ledTime[] = {"00:00", "00:15", "00:30", "00:45", "01:00", "01:15", "01:30", "01:45", "02:00", "02:15", "02:30", "02:45", "03:00", "03:15", "03:30", "03:45", "04:00", "04:15", "04:30", "04:45", "05:00", "05:15", "05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "08:15", "08:30", "08:45", "09:00", "09:15", "09:30", "09:45", "10:00", "10:15", "10:30", "10:45", "11:00", "11:15", "11:30", "11:45", "12:00", "12:15", "12:30", "12:45", "13:00", "13:15", "13:30", "13:45", "14:00", "14:15", "14:30", "14:45", "15:00", "15:15", "15:30", "15:45", "16:00", "16:15", "16:30", "16:45", "17:00", "17:15", "17:30", "17:45", "18:00", "18:15", "18:30", "18:45", "19:00", "19:15", "19:30", "19:45", "20:00", "20:15", "20:30", "20:45", "21:00", "21:15", "21:30", "21:45", "22:00", "22:15", "22:30", "22:45", "23:00", "23:15", "23:30", "23:45"};
int ch1[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,5,12,24,36,48,60,72,84,96,108,120,132,144,156,168,180,192,204,216,228,240,232,224,216,208,200,192,184,176,168,160,152,144,136,128,120,112,104,96,88,80,72,64,56,48,40,32,24,16,5,0,0,0,0,0,0,0,0,0,0};
int ch2[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,18,36,54,72,90,108,126,144,162,180,198,216,234,252,237,222,207,192,177,162,147,132,117,102,87,72,57,42,27,12,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int ch3[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,9,18,27,36,45,54,63,72,81,90,99,108,117,126,135,144,153,162,153,144,135,126,117,108,99,90,81,72,63,54,45,36,27,18,9,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int ch4[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,6,18,36,54,72,90,108,126,144,150,139,128,117,106,95,84,73,62,51,40,29,18,7,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int fan[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,25,50,75,100,125,150,175,200,255,255,200,175,150,125,100,75,50,25,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

void setup()   /*----( SETUP: RUNS ONCE )----*/
{
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(3, OUTPUT);

  // Start rtc stuff
  Wire.begin();
  rtc.begin();

}/*--(end setup )---*/


void loop()   /*----( LOOP: RUNS CONSTANTLY )----*/
{

  DateTime now = rtc.now(); //get the current date-time
  
  int HR = now.hour();
  int MIN = now.minute();
  String timeNow= String(HR)+":"+String(MIN);
  
  for (int x=0; x<sizeof(ledTime); x=x+1){
    if (String(ledTime[x]) == timeNow){
       analogWrite(5, ch4[x]);
       analogWrite(6, ch3[x]);
       analogWrite(9, ch2[x]);
       analogWrite(10, ch1[x]);
       analogWrite(3, fan[x]);
       x = sizeof(ledTime);
    }
  }

}/* --(end main loop )-- */

I’m guessing that the memory usage is cause of the arrays, is there a better way to set it up.

Also in the loop I go through to check if the current timematches any in the array using a for loop, does the arduino ide have something like python where you can get an index from a value.

#2

Where do the values come from originally? Was there some formula that computed them?

And ledTime isn't this just a incredibly wasteful way of saying we want something every 15 minutes? Or is it seconds?

-jim lee

#3

No values are just from an excel spreadsheet just randomly and adjusted to how i needed them.

When I originally started using the time to find the indexed seemed simple and like a great idea, but looking back at it yeah it does seem terrible.
Switched up a bit got rid of the ledTime and instead used every 15 mins. mem usage down to 58 :slight_smile:

void loop()   /*----( LOOP: RUNS CONSTANTLY )----*/
{

  DateTime now = rtc.now(); //get the current date-time

  int HR = now.hour();

  //  String timeNow = String(HR) + ":" + String(MIN);

  if (now.minute() == 00) {
    int quarter = 0;
  }
  if  (now.minute() == 15) {
    int quarter = 1;
  }
  if  (now.minute() == 30) {
    int quarter = 2;
  }
  if  (now.minute() == 45) {
    int quarter = 3;
  }

  int index = (HR * 4) + quarter;
  analogWrite(5, ch4[index]);
  analogWrite(6, ch3[index]);
  analogWrite(9, ch2[index]);
  analogWrite(10, ch1[index]);
  analogWrite(3, fan[index]);


}/* --(end main loop )-- */

Its funny how just talking to someone about something can open ways you might never think about lol.
Anything else i can improve on.

#4

Not a good coder, but can you change this

int ch1… // all values are 8-bit

to this

byte ch1… // byte datatype halves the used memory

Leo…

#5

Note the number of leading zeros in each array, then clip them out of the arrays. Then when accessing an array value. For example:

for (int i=0;i<=maxi;i++) {

   if (i<ch1StartIndex) {
      use(0);
   } else {
      use(ch1[i-ch1StartIndex]);
   }
   ...
   ...

-jim lee

#6

Just look it up howto place the big fixed arrays in prom NOT ram.

Mark

#7

Thanks for all the tips guys, changed all the arrays from int to bytes, got rid of all the zeroes and called a function to write it using the start index as jimlee suggested.

I know my coding is terrible but practise makes perfect i guess.

Heres my final code for now

#include <Wire.h>
#include "Sodaq_DS3231.h"

byte ch1[] = {1, 5, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240, 232, 224, 216, 208, 200, 192, 184, 176, 168, 160, 152, 144, 136, 128, 120, 112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 5};
byte ch2[] = {8, 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198, 216, 234, 252, 237, 222, 207, 192, 177, 162, 147, 132, 117, 102, 87, 72, 57, 42, 27, 12, 5};
char ch3[] = {1, 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 153, 144, 135, 126, 117, 108, 99, 90, 81, 72, 63, 54, 45, 36, 27, 18, 9, 3};
byte ch4[] = {6, 18, 36, 54, 72, 90, 108, 126, 144, 150, 139, 128, 117, 106, 95, 84, 73, 62, 51, 40, 29, 18, 7, 2};
//temp until temp sensor comes in
byte fan[] = {25, 50, 75, 100, 125, 150, 175, 200, 255, 255, 200, 175, 150, 125, 100, 75, 50, 25};
int quarter = 0, oldQuarter = 9;
void setup()   /*----( SETUP: RUNS ONCE )----*/
{
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(3, OUTPUT);

  // Start rtc stuff
  Wire.begin();
  rtc.begin();

}/*--(end setup )---*/


void loop()   /*----( LOOP: RUNS CONSTANTLY )----*/
{

  DateTime now = rtc.now(); //get the current date-time
  int HR = now.hour();

  if (now.minute() == 00) {
    quarter = 0;
  }
  if  (now.minute() == 15) {
    quarter = 1;
  }
  if  (now.minute() == 30) {
    quarter = 2;
  }
  if  (now.minute() == 45) {
    quarter = 3;
  }
  // only run if time has changed +15 mins
  if (oldQuarter != quarter) {
    int index = (HR * 4) + quarter;
    indexCalc(index);
    oldQuarter = quarter;
  }


}/* --(end main loop )-- */

void indexCalc(int x ) {
  int index = x, ch1Start = 35, ch2Start = 42, ch3Start = 39, ch4Start = 48, fanStart = 48;
  // CH1 write
  if (index < ch1Start || index > sizeof(ch1) + ch1Start) {
    analogWrite(5, 0);
  } else {
    analogWrite(5, ch1[index - ch1Start]);
  }
  // CH2 write
  if (index < ch2Start || index > sizeof(ch2) + ch2Start) {
    analogWrite(6, 0);
  } else {
    analogWrite(6, ch2[index - ch2Start]);
  }
  // CH3 write
  if (index < ch3Start || index > sizeof(ch3) + ch3Start) {
    analogWrite(9, 0);
  } else {
    analogWrite(9, ch3[index - ch3Start]);
  }
  // CH4 write
  if (index < ch4Start || index > sizeof(ch4) + ch4Start) {
    analogWrite(10, 0);
  } else {
    analogWrite(10, ch4[index - ch4Start]);
  }
  // Fan write
  if (index < fanStart || index > sizeof(fan) + fanStart) {
    analogWrite(3, 0);
  } else {
    analogWrite(3, fan[index - fanStart]);
  }
}
#8