Assignment: Digital I/O with Arduino Boards + Diffuser

Collaborators:

Description

I created a diffuser using a piece of paper and making an origami ball in order to fit over the LEDs. The user can adjust the lights with multiple key presses of 'r', 'g', or/and 'b'. For example, "rrr" will increase the red LED by 30%.

Components Used

• Red Light Emitting Diode (LED)
• Green Light Emitting Diode (LED)
• Blue Light Emitting Diode (LED)
• 3 Resistors
• Paper

Arduino Code

/* 
 * Serial RGB LED
 * ---------------
 * Serial commands control the brightness of R,G,B LEDs 
 *
 * Command structure is "<colorCode>*", where "colorCode" is
 * one of "r","g",or "b" and * states thate the command can be repeated many times. Each colorCode increaeses
 * the light by 10%. 
 *
 * E.g. "rrr"  Increases the red LED by 30%.  
 *      "rrggbb" Increases the red, green and blue LED light by 30%.
 *      "rgggg"  Increases the red LED by 10% and the green LED by 40%.
 *
 * Note that the light accumlates until it reaches 255, then the light resets.
 *
 * Created 18 October 2006
 * copyleft 2006 Tod E. Kurt <tod@todbot.com
 * http://todbot.com/
 *
 * Modifed September 13, 2009
 * By Lita Cho
 */

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

int redPin   = 10;   // Red LED,   connected to digital pin 9
int greenPin = 9;  // 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 a color command (e.g. 'rrrgg') :");  
}

void loop () {
  // clear the string
  memset(serInString, 0, 100);
  //read the serial port and create a string out of what you read
  readSerialString(serInString);
  parseInput(serInString, 100);
  readSerialString(serInString);
  delay(100);  // wait a bit, for serial data
}

// Method to parse the inputs
void parseInput(char *strArray, int length) {
  int i = 0; // Counter
  int colorCode;
  while ( i < length && strArray[i] != '\0') {
    colorCode = strArray[i];
    
    if(colorCode == 'r') {
      redValue = (redValue + 10) % 255;
      Serial.print("Red Value: ");
      Serial.println(redValue);
      analogWrite(redPin, redValue);
    } else if(colorCode == 'g') {
      greenValue = (greenValue + 10) % 255;
      Serial.print("Green Value: ");
      Serial.println(greenValue);
      analogWrite(greenPin, greenValue);
    } else if(colorCode == 'b') {
      blueValue = (blueValue + 10) % 255;
      Serial.print("Blue Value: ");
      Serial.println(blueValue);
      analogWrite(bluePin, blueValue);
    }
    
    ++i;
  }
}

//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++;
  }
}

Picture