Using LED Strips for Day/Night Cycle

[Sugar]

Fantastic Andrew,
Have you had any advances since posting this?

[conrailandrew]

Yep, I've put a knob on it that lets me control the rate of the cycle. I have yet to do the tweaking of the exact colors, but that will come soon, then I'll post an updated code.

Thanks,
Andrew

[Claymore1977]

Looks fantastic sir. Excellent work!

Have you measured the total current draw for the system?

[Moose2013]

Moose like the design and effects. Thank you for the article.

Moose just getting interested in possibilities of electronic / computerized controls over layout, a step beyond DCC locomotives themselves, to the building interior & exterior lighting, street lamps, etc. What you have shown would add a new dimension I hadn't thought about controlling automatically.

Wow! Moose now must travel to Moose Jaw, Saskatchewan, and drop my jaw at your creativity ... Okay, that was funnier in my big moose head...

Again, thanks for article!

[conrailandrew]

Looks fantastic sir. Excellent work!

Have you measured the total current draw for the system?

I did measure it when I first did this, but I don't remember what it was now. It was way less than what I expected.

Andrew

[conrailandrew]

Quick update:

I updated the code tonight to add a randomized lightning storm. Right now, the day/night cycle pauses until the thunderstorm completes, then continues. I plan to fix this in the near future, and will keep this thread updated. There is a 1:50,000 chance of a thunderstorm happening at a point in the loop of the code, at this point only in evenings and nights.

Also, if anyone wants to use this, I can go go through and make it more user friendly for someone not familiar with writing code.

Future plans include:
Allow day time storms, darkening light ambiance to suit
Adding synchronized storm sounds
Changing the colors to look more realistic
Setting time cycle to more closely match real day light levels
(maybe...) adding a fast clock on a LCD display shield
Controls to jump to certain times of day

Video will be uploaded tomorrow.

Here's the code:

/*
* Code for cross-fading 3 LEDs, red, green and blue (RGB) 
* To create fades, you need to do two things: 
*  1. Describe the colors you want to be displayed
*  2. List the order you want them to fade in
*
* DESCRIBING A COLOR:
* A color is just an array of three percentages, 0-100, 
*  controlling the red, green and blue LEDs
*
* Red is the red LED at full, blue and green off
*   int red = { 100, 0, 0 }
* Dim white is all three LEDs at 30%
*   int dimWhite = {30, 30, 30}
* etc.
*
* Some common colors are provided below, or make your own
* 
* LISTING THE ORDER:
* In the main part of the program, you need to list the order 
*  you want to colors to appear in, e.g.
*  crossFade(red);
*  crossFade(green);
*  crossFade(blue);
*
* Those colors will appear in that order, fading out of 
*    one color and into the next  
*
* In addition, there are 5 optional settings you can adjust:
* 1. The initial color is set to black (so the first color fades in), but 
*    you can set the initial color to be any other color
* 2. The internal loop runs for 1020 interations; the 'wait' variable
*    sets the approximate duration of a single crossfade. In theory, 
*    a 'wait' of 10 ms should make a crossFade of ~10 seconds. In 
*    practice, the other functions the code is performing slow this 
*    down to ~11 seconds on my board. YMMV.
* 3. If 'repeat' is set to 0, the program will loop indefinitely.
*    if it is set to a number, it will loop that number of times,
*    then stop on the last color in the sequence. (Set 'return' to 1, 
*    and make the last color black if you want it to fade out at the end.)
* 4. There is an optional 'hold' variable, which pasues the 
*    program for 'hold' milliseconds when a color is complete, 
*    but before the next color starts.
* 5. Set the DEBUG flag to 1 if you want debugging output to be
*    sent to the serial monitor.
*
*    The internals of the program aren't complicated, but they
*    are a little fussy -- the inner workings are explained 
*    below the main loop.
*/ 




//Input
int sensorPin = A0;    // select the input pin for the potentiometer for cycle speed
int sensorValue = 20;  // variable to store the value coming from the sensor
int knob = 20;




// Output
int cwhPin = 3;   // Cool White LED, connected to digital pin 3
int wwhPin = 5;   // Warm White LED, connected to digital pin 5
//int auxPin = 6;   // For other LED (if any) connected to digital pin 6
int redPin = 9;   // Red LED,   connected to digital pin 9
int grnPin = 10;  // Green LED, connected to digital pin 10
int bluPin = 11;  // Blue LED,  connected to digital pin 11




// Color arrays
int white[5]  =     { 100, 100, 100, 100, 100 };
int red[5]    =     { 100, 0, 0, 0, 0 };
int green[5]  =     { 0, 100, 0, 0, 0 };
int blue[5]   =     { 0, 0, 100, 0, 0 };
int yellow[5] =     { 60, 50, 0, 0, 0 };
int dimWhite[5] =   { 30, 30, 30, 30, 30 };
int black[5]  =     { 0, 0, 0, 0, 0 };




int dawnone[5] =    { 98, 90, 70, 0, 0};
int dawntwo[5]  =   { 95, 20, 10, 0, 0 };
int dawnthree[5] =  { 100, 57, 30, 70, 50 };
int carbonarc[5]  = { 100, 97, 80 , 70, 100};
int sun[5] =        { 100, 100, 80, 100, 100 };
int noon[5] =       { 100, 100, 90, 100, 100 };
int duskone[5] =    { 97, 85, 56, 0, 0 };
int dusktwo[5] =    { 20, 40, 70, 0, 0 };
int blueone[5] =    { 0, 10, 30, 0, 0 };
int bluetwo[5] =    { 0, 0, 20, 0, 0 };
// etc.




// Set initial color
int redVal = black[0];
int grnVal = black[1]; 
int bluVal = black[2];
int cwhVal = black[3];
int wwhVal = black[4];




//int wait = sensorValue;      // 10ms internal crossFade delay; increase for slower fades
int hold = 0;       // Optional hold when a color is complete, before the next crossFade
int DEBUG = 1;      // DEBUG counter; if set to 1, will write values back via serial
int loopCount = 60; // How often should DEBUG report?
int repeat = 0;     // How many times should we loop before stopping? (0 for no stop)
int j = 0;          // Loop counter for repeat




// Initialize color variables
int prevR = redVal;
int prevG = grnVal;
int prevB = bluVal;
int prevC = cwhVal;
int prevW = wwhVal;


//Lightning stuff
int ledPin11 = 11;
int burst; //short burst of light
int big;
int srumble;
int brumble;
int mixer;
int diming;
int delaymix;
int dark;
int lightningtimer;
int lightningtime;
int count;
int wait;
int lightningOn;
int lightningSelect = 1; //Set to 0 to disable lightning


// Set up the LED outputs
void setup()
{
  pinMode(redPin, OUTPUT);   // sets the pins as output
  pinMode(grnPin, OUTPUT);   
  pinMode(bluPin, OUTPUT); 
  pinMode(cwhPin, OUTPUT);
  pinMode(wwhPin, OUTPUT);
  
  if (DEBUG) {           // If we want to see values for debugging...
    Serial.begin(9600);  // ...set up the serial ouput 
  }
}




// Main program: list the order of crossfades
void loop()




  // read the value from the sensor:
  {
  crossFade(dawntwo);
  crossFade(dawnone);
  crossFade(dawnthree);
  crossFade(carbonarc);
  crossFade(sun);
  crossFade(noon);
  crossFade(sun);
  crossFade(duskone);
  crossFade(black);
  crossFade(dusktwo);
  crossFade(blueone);
  crossFade(bluetwo);
  crossFade(black);
  crossFade(black);
  




  if (repeat) { // Do we loop a finite number of times?
    j += 1;
    if (j >= repeat) { // Are we there yet?
      exit(j);         // If so, stop.
    }
  }
  
  sensorValue = analogRead(sensorPin);
  int wait = sensorValue;
}




/* BELOW THIS LINE IS THE MATH -- YOU SHOULDN'T NEED TO CHANGE THIS FOR THE BASICS
* 
* The program works like this:
* Imagine a crossfade that moves the red LED from 0-10, 
*   the green from 0-5, and the blue from 10 to 7, in
*   ten steps.
*   We'd want to count the 10 steps and increase or 
*   decrease color values in evenly stepped increments.
*   Imagine a + indicates raising a value by 1, and a -
*   equals lowering it. Our 10 step fade would look like:
* 
*   1 2 3 4 5 6 7 8 9 10
* R + + + + + + + + + +
* G   +   +   +   +   +
* B     -     -     -
* 
* The red rises from 0 to 10 in ten steps, the green from 
* 0-5 in 5 steps, and the blue falls from 10 to 7 in three steps.
* 
* In the real program, the color percentages are converted to 
* 0-255 values, and there are 1020 steps (255*4).
* 
* To figure out how big a step there should be between one up- or
* down-tick of one of the LED values, we call calculateStep(), 
* which calculates the absolute gap between the start and end values, 
* and then divides that gap by 1020 to determine the size of the step  
* between adjustments in the value.
*/




int calculateStep(int prevValue, int endValue) {
  int step = endValue - prevValue; // What's the overall gap?
  if (step) {                      // If its non-zero, 
    step = 1020/step;              //   divide by 1020
  } 
  return step;
}




/* The next function is calculateVal. When the loop value, i,
*  reaches the step size appropriate for one of the
*  colors, it increases or decreases the value of that color by 1. 
*  (R, G, and B are each calculated separately.)
*/




int calculateVal(int step, int val, int i) {




  if ((step) && i % step == 0) { // If step is non-zero and its time to change a value,
    if (step > 0) {              //   increment the value if step is positive...
      val += 1;           
    } 
    else if (step < 0) {         //   ...or decrement it if step is negative
      val -= 1;
    } 
  }
  // Defensive driving: make sure val stays in the range 0-255
  if (val > 255) {
    val = 255;
  } 
  else if (val < 0) {
    val = 0;
  }
  return val;
}




/* crossFade() converts the percentage colors to a 
*  0-255 range, then loops 1020 times, checking to see if  
*  the value needs to be updated each time, then writing
*  the color values to the correct pins.
*/




void crossFade(int color[5]) {
  // Convert to 0-255
  int R = (color[0] * 255) / 100;
  int G = (color[1] * 255) / 100;
  int B = (color[2] * 255) / 100;
  int C = (color[3] * 255) / 100;
  int W = (color[4] * 255) / 100;




  int stepR = calculateStep(prevR, R);
  int stepG = calculateStep(prevG, G); 
  int stepB = calculateStep(prevB, B);
  int stepC = calculateStep(prevC, C);
  int stepW = calculateStep(prevW, W);




  for (int i = 0; i <= 1020; i++) {
    redVal = calculateVal(stepR, redVal, i);
    grnVal = calculateVal(stepG, grnVal, i);
    bluVal = calculateVal(stepB, bluVal, i);
    cwhVal = calculateVal(stepC, cwhVal, i);
    wwhVal = calculateVal(stepW, wwhVal, i);
  
    analogWrite(redPin, redVal);   // Write current values to LED pins (added the "255 - " to each of these three to accomodate common anode LED. ex:  analogWrite(wwhPin, 255 - wwhVal);   ) Andrew Kyle
    analogWrite(grnPin, grnVal);      
    analogWrite(bluPin, bluVal);
    analogWrite(cwhPin, cwhVal);
    analogWrite(wwhPin, wwhVal); 




    delay(analogRead(sensorPin)); // Pause for 'wait' milliseconds before resuming the loop
    knob = analogRead(sensorPin);
//lightning
    lightningOn = random(1-50000);
    if (W < 30 && C < 30 && R < 20 && G < 20 && lightningOn == 1 && lightningSelect != 0){
      burst = random(10,100); //Short burst of lightning value
      big = random(500,1000);//long burst of lightning value
      srumble = random(10,40);//lower light lighting value
      brumble = random(10,150);//higher light lightning value
      mixer = random(burst,big);//random pick of short or long bursts of lightning
      dark = random(1000,12000);//random pick of time gap for lightning
      count = random(3,7);//how long storm lasts
      for(int i = 0; i < count; i++){
        burst = random(10,500); //Short burst of lightning value
        big = random(500,1000);//long burst of lightning value
        srumble = random(1,50);//lower light lighting value
        brumble = random(50,1503);//higher light lightning value
        mixer = random(burst,big);//random pick of short or long bursts of lightning
        for(int i = 0; i < mixer; i += diming++){
          diming = random(1,150);
          analogWrite(cwhPin, random(srumble,brumble));//Turn on LED for short or long burst
          analogWrite(wwhPin, random(srumble,brumble));//Turn on LED for short or long burst
          delay(diming);//random number delay to remain at set brightness value
        }
        digitalWrite(cwhPin, LOW);    // turn the LED off
        digitalWrite(wwhPin, LOW);    // turn the LED off
        //delay(dark);
        wait = random(1000, 12000);
        delay(wait);
        count - 1;
        if (count < 0){
          break;
        }
      }
    }
//end lightning
    if (DEBUG) { // If we want serial output, print it at the 
      if (i == 0 or i % loopCount == 0) { // beginning, and every loopCount times
        Serial.print("Loop/RGBCW: #");
        Serial.print(i);
        Serial.print(" | ");
        Serial.print(redVal);
        Serial.print(" / ");
        Serial.print(grnVal);
        Serial.print(" / ");
        Serial.print(bluVal);
        Serial.print(" / ");
        Serial.print(cwhVal);
        Serial.print(" / ");
        Serial.println(wwhVal);
        Serial.print(knob);
        Serial.print(" , ");
        Serial.println(sensorPin);
        
      } 
      DEBUG += 1;
    }
  }
  // Update current values for next loop
  prevR = redVal; 
  prevG = grnVal; 
  prevB = bluVal;
  prevC = cwhVal;
  prevW = wwhVal;
  delay(hold); // Pause for optional 'wait' milliseconds before resuming the loop
}

Andrew

[ScottL]

So awesome. Thanks for posting the code.

[zosimas]

Wheres the video of thunder storm?

[conrailandrew]

Wheres the video of thunder storm?

Right here:


There are three storms in that clip, the last one is the most dramatic.
Also, the reason it cycles through the day so fast is because I have the speed turned all the way up to increase the chances of a thunderstorm coming along. Even so I was pretty lucky to get three thunderstorms in that amount of time. Sometimes it will go for quite a few day/night cycles before spawning another storm.
This video was taken before some modifications that required it to be a bit darker before storming, and before I added the code that also makes the second white strip flash with the lightning, making the flashes brighter. It's pretty impressive when a thunderstorm happens in the middle of the 'night', it can be rather of a surprise when that first strike hits.

Andrew