Arduino RGB LED color fade
When the potentiometer is = 0 the light will shine white
When you began to turn it to the right the LED will cycle through all the colors
Once it reaches <899 the LED will continuously cycle through colors
code:
(tags added by moderator)
int LEDGreen=9;
int LEDBlue=10;
int LEDRed=11;
int sensorPin=0;
int val;
// Output
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 black[3] = { 0, 0, 0 };
int white[3] = { 100, 100, 100 };
int red[3] = { 100, 0, 0 };
int green[3] = { 0, 100, 0 };
int blue[3] = { 0, 0, 100 };
int yellow[3] = { 40, 95, 0 };
int dimWhite[3] = { 30, 30, 30 };
// etc.
// Set initial color
int redVal = black[0];
int grnVal = black[1];
int bluVal = black[2];
int wait = 1; // 10ms internal crossFade delay; increase for slower fades
int hold = 1; // 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 = 0; // 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;
void setup(){
Serial.begin(9600);
pinMode(LEDRed,OUTPUT);
pinMode(LEDGreen,OUTPUT);
pinMode(LEDBlue,OUTPUT);
}
void loop(){
val=map(analogRead(sensorPin),0,1023,0,900);
Serial.println(val);
if(val>=899) {
crossFade(red);
crossFade(green);
crossFade(blue);
//cycle colors
} else if(val==0){
analogWrite(LEDRed, 0);
analogWrite(LEDGreen, 0);
analogWrite(LEDBlue, 0);
} else {
if (val < 1){
analogWrite(LEDRed, 0);
analogWrite(LEDGreen, 0);
analogWrite(LEDBlue, 0);
Serial.println("boo");
} else if (val<150) {
analogWrite(LEDRed,0);
analogWrite(LEDBlue,255);
analogWrite(LEDGreen,255);
Serial.println("150");
} else if (val<300) {
analogWrite(LEDRed,map(val,150,300,0,255));
analogWrite(LEDBlue,map(val,150,300,255,0));
analogWrite(LEDGreen,255);
} else if (val<450) {
analogWrite(LEDRed,255);
analogWrite(LEDBlue,0);
analogWrite(LEDGreen,255);
} else if (val<600) {
analogWrite(LEDRed,255);
analogWrite(LEDBlue,map(val,450,600,0,255));
analogWrite(LEDGreen,map(val,450,600,255,0));
} else if (val<750) {
analogWrite(LEDRed,255);
analogWrite(LEDBlue,255);
analogWrite(LEDGreen,0);
} else if (val<900) {
analogWrite(LEDRed,map(val,750,900,255,0));
analogWrite(LEDBlue,255);
analogWrite(LEDGreen,map(val,750,900,0,255));
}
//stop cycling colors
}
delay(10);
}
/* 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[3]) {
// Convert to 0-255
int R = (color[0] * 255) / 100;
int G = (color[1] * 255) / 100;
int B = (color[2] * 255) / 100;
int stepR = calculateStep(prevR, R);
int stepG = calculateStep(prevG, G);
int stepB = calculateStep(prevB, B);
for (int i = 0; i <= 1020; i++) {
redVal = calculateVal(stepR, redVal, i);
grnVal = calculateVal(stepG, grnVal, i);
bluVal = calculateVal(stepB, bluVal, i);
analogWrite(redPin, redVal); // Write current values to LED pins
analogWrite(grnPin, grnVal);
analogWrite(bluPin, bluVal);
delay(wait); // Pause for 'wait' milliseconds before resuming the loop
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/RGB: #");
Serial.print(i);
Serial.print(" | ");
Serial.print(redVal);
Serial.print(" / ");
Serial.print(grnVal);
Serial.print(" / ");
Serial.println(bluVal);
}
DEBUG += 1;
}
}
// Update current values for next loop
prevR = redVal;
prevG = grnVal;
prevB = bluVal;
delay(hold); // Pause for optional 'wait' milliseconds before resuming the loop
}
