Description

• First, I added two additional LEDs and then made their brightnesses appear to fade
• With the LEDs in serial, a program was uploaded that allowed me to enter brightness values
• I created a diffuser out of a white candle
• I wrote code so that i was able to enter between 1 and 10 r, g, or bs and translated them to a color value between 0 and 255

Components Used

• Breadboard
• White wax candle
• 3 Light Emitting Diode (LED)
• Resistor
• Rubber bands

Arduino Code

/* 
 * Percentge Serial RGB LED
 * ---------------
 * Serial commands control the brightness of R,G,B LEDs 
 *
 * Command structure is "<colorCode><colorVal>", where "colorCode" is
 * one of "r","g",or "b" is equivalent to a 10% change in brightness.  rrr would be approximately a value of 76.
 *
 *
 * Created 18 October 2006
 * copyleft 2006 Tod E. Kurt <tod@todbot.com
 * http://todbot.com/
 *
 * Modified September 16 2009
 * by Heather Dolan
 * for a TUI lab
 */

char serInString[100];  // array that will hold the different bytes of the string. 100=100characters;
                        // -> you must state how long the array will be else it won't work properly
char colorCode;
int colorVal;
int numLetter;
int x;

int redPin   = 9;   // Red LED,   connected to digital pin 9
int greenPin = 10;  // Green LED, connected to digital pin 10
int bluePin  = 11;  // Blue LED,  connected to digital pin 11

void setup() {
  //int x = 0;
  pinMode(redPin,   OUTPUT);   // sets the pins as output
  pinMode(greenPin, OUTPUT);   
  pinMode(bluePin,  OUTPUT);
  Serial.begin(9600);
  analogWrite(redPin,   5);   // set them all to mid brightness
  analogWrite(greenPin, 5);   // set them all to mid brightness
  analogWrite(bluePin,  0);   // set them all to mid brightness
  Serial.println("enter color command (e.g. 'r' or 'rrr', etc.  One letter is nearly equivalent to a 10% increment) :");  
}

void loop () {
  //read the serial port and create a string out of what you read

  readSerialString(serInString);
   Serial.print(serInString[0]);
    x = 0;
    numLetter = 0;
  colorCode = serInString[0];
  while(serInString[x]!=false) {
  if(colorCode == 'r' || colorCode == 'g' || colorCode == 'b') {
      
     numLetter = 1 + numLetter;  //increment the counter for the number letters entered

     serInString[x]=0; //clear the string

  }
  

  x++;
  } 

//set the color and output the value
  colorVal = getColorValue(numLetter);

  
    if(colorCode == 'r') {
      analogWrite(redPin, colorVal);
      Serial.print("Red Color Value equals: ");
      Serial.print(colorVal);
      Serial.println();
     

      
    }
    else if(colorCode == 'g'){
      
      analogWrite(greenPin, colorVal);
      Serial.print("Green Color Value equals: ");
      Serial.print(colorVal);
      Serial.println();

    }
    else if(colorCode == 'b'){
      analogWrite(bluePin, colorVal);
     Serial.print("Blue Color Value equals: ");
     Serial.print(colorVal);
     Serial.println();
   
    }
  
  delay(100);  // wait a bit, for serial data
}

//read a string from the serial and store it in an array
//you must supply the array variable
void readSerialString (char *strArray) {
  int i = 0;
  if(!Serial.available()) {
    return;
  }
  while (Serial.available()) {
    strArray[i] = Serial.read();
    i++;
  }
}

//Function for converting the number of letters entered to an 8-bit color value
int getColorValue (int nL) {
  int cV;
  cV = nL*.1* 255;
  
  return cV;
}
    

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