Code used in this Assignment:

/* 

 * 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" and "colorVal" is a number 0 to 255.

 * E.g. "r0"   turns the red LED off.  

 *      "g127" turns the green LED to half brightness

 *      "b64"  turns the blue LED to 1/4 brightness

 *

 * Alternate command structure is "<colorCode>*", where "colorCode" is

 * one of "r","g", or "b".

 * E.g. "r"    increases the red LED brightness by 10

 *      "rrr"  increases the red LED brightness by 30

 *      "ggb"  increases the green LED brightness by 20 and the blue by 10

 *

 * Created 18 October 2006

 * copyleft 2006 Tod E. Kurt <tod@todbot.com

 * http://todbot.com/

 *

 * Adapted 5 September 2007

 * copylefter 2007 Ryan Aipperspach <ryanaip@alumni.rice.edu>

 *

 */

//include support for manipulating strings.

//for a useful string comparison function, see the bottom of this file... stringsEqual()

//#include <stdio.h>//

#include <string.h>

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 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

int redValue = 127;

int greenValue = 127;

int blueValue = 127;

void setup() {

  pinMode(redPin,   OUTPUT);   // sets the pins as output

  pinMode(greenPin, OUTPUT);   

  pinMode(bluePin,  OUTPUT);

  Serial.begin(9600);

  analogWrite(redPin,   redValue);   // set them all to mid brightness

  analogWrite(greenPin, greenValue);   // set them all to mid brightness

  analogWrite(bluePin,  blueValue);   // set them all to mid brightness

  Serial.println("enter color command (e.g. 'r43 or rrrrrrrrbbbb') :");  

}

void loop () {

  //read the serial port and create a string out of what you read

  readSerialString(serInString, 100);

  //UNCOMMENT ONE OF THE FOLLOWING COMMANDS, OR NOTHING WILL HAPPEN WHEN YOU

  //RUN THE PROGRAM...

  //Uncomment the following line to read commands of the form 'r245' or 'b3'  

  //processNumericalCommands(serInString);

  //Uncomment the following line to read commands of the form 'rrrb'

  //processRepeatKeyCommands(serInString, 100);

  //Or write your own function...

  //YOUR_FUNCTION_HERE(serInString);

  //Erase anything left in the serial string, preparing it for the 

  //next loop

  resetSerialString(serInString, 100);  

  delay(100);  // wait a bit, for serial data

}

void resetSerialString (char *strArray, int length) {

  for (int i = 0; i < length; i++) {

    strArray[i] = '\0';

  }

}

//read a string from the serial and store it in an array

//you must supply the array variable

void readSerialString (char *strArray, int maxLength) {

  int i = 0;

  if(!Serial.available()) {

    return;

  }

  while (Serial.available() && i < maxLength) {

    strArray[i] = Serial.read();

    i++;

  }

}

//go through the string, and increase the red value for each 'r',

//the green value for each 'g', and the blue value for each 'b'.

//For example "rrrg" increases red by 30 and green by 10.

void processRepeatKeyCommands(char *strArray, int maxLength) {

  int i = 0;

  //loop through the string (strArray)

  //i = the current position in the string

  //Stop when either (a) i reaches the end of the string or

  //                 (b) there is an empty character '\0' in the string

  while (i < maxLength && strArray[i] != '\0') {

    //Read in the character at position i in the string

    colorCode = serInString[i];

    //If the character is r (red)...

    if (colorCode == 'r') {

      //Increase the current red value by 10, and if you reach 255 go back to 0

      redValue = (redValue + 10) % 255;

      analogWrite(redPin, redValue);

      Serial.print("setting color r to ");

      Serial.println(redValue);

    //If the character is g (green)...

    } else if (colorCode == 'g') {

      greenValue = (greenValue + 10) % 255;

      analogWrite(greenPin, greenValue);

      Serial.print("setting color g to ");

      Serial.println(greenValue);

    //If the character is b (blue)...

    } else if (colorCode == 'b') {

      blueValue = (blueValue + 10) % 255;

      analogWrite(bluePin, blueValue);

      Serial.print("setting color b to ");

      Serial.println(blueValue);

    }

    //Move on to the next character in the string

    //From here, the code continues executing from the "while" line above...

    i++;

  }

}

//change the value of the red, green, or blue LED according to the command received.

//for example, r240 sets the red LED to the value 240 (out of 255)

void processNumericalCommands(char *strArray) {

  //read in the first character in the string

  colorCode = serInString[0];

  //if the first character is r (red), g (green) or b (blue), do the following...

  if( colorCode == 'r' || colorCode == 'g' || colorCode == 'b' ) {

    //convert the string to an integer

    //(start at the second character, or the beginning of the string '+1')

    colorVal = atoi(serInString+1);

    Serial.print("setting color ");

    Serial.print(colorCode);

    Serial.print(" to ");

    Serial.print(colorVal);

    Serial.println();

    if(colorCode == 'r') 

      analogWrite(redPin, colorVal);

    else if(colorCode == 'g')

      analogWrite(greenPin, colorVal);

    else if(colorCode == 'b')

      analogWrite(bluePin, colorVal);

  }

}

//compare two strings to see if they are equal

//compares the first 'numCharacters' characters of string1 and string2 to

//see if they are the same

//

//E.g. stringsEqual("hello","hello",5) => true

//     stringsEqual("hello","helaabbnn",3) => true

//     stringsEqual("hello","helaa",5) => false

boolean stringsEqual(char *string1, char *string2, int numCharacters) {

  if (strncmp(string1, string2, numCharacters) == 0) {

    return true;

  } else {

    return false;

  }

}