Digital I/O with Arduino Boards + Diffuser

In this lab we learnt to implement an analog output using a digital input. The technique is called Pulse Wave Modulation. Also, user input was taken via arduino serial port to implement customized light colors.
The circuit was created as per the diagram provided in class.
Materials 
1 breadboard, 1 Arduino, 3 LED(red,green,blue), 3 220ohms resistors, connecting wires
 
Diffusor
I used a disposable paper cup and tissue paper to create my diffusor. 
 

After learning Pulse Width Modulation and serial communication with the laptop at the lab, this assignment of building the LED diffuser was to explore these features in more depth. I started with setting three resistors, LED lights, and connecting wires. I carefully built LED circuit by using pin 9, 10, and 11, which can support Pulse Width Modulation. Then, by using the Arduino Sketchbook, I coded a program so that I can control RGB values of LED lights by pressing letters ‘r’, ‘g’, and ‘b’ multiple times.

                This lab focused on Pulse Width Modulation (PWM) to simulate analog behavior as well as serial communication between the computer and Arduino Uno Microcontroller. 

/*
 * Serial RGB LED -- Modified by Shaun Giudici
 * ---------------
 * Serial commands control the brightness of R,G,B LEDs
*
 * Script will count the occurrances of R's G's and B's
 * Each occurance will count for 20% brightness
 *
 * Script will also count nmuber of F's
 * More F's == More Speed
 *
 * For example the command "rrrgbfff" will set red led to 60%, green led to 20% and blue led to 20% at medium speed

 
Description
For this week's lab we had to choose a good diffuser for our RGB LEDs. My winner was a Tide wash bag that gave an almost omogenous effect of color. I uploaded a video with the result on youtube (http://www.youtube.com/watch?v=GhfzUGG6OrQ).

Description:
In this lab we used the serial terminal to enter inputs controling 3 LEDs. Our next instruction was to find a diffusor to diffuse the light. I chose a mini-haloween lamp shade since haloween is coming up. With my code an entry of a any single letter, 'r', 'g', 'b', increases the brightness by 10%, while an entry of 'z' resets all brightness to zero. 
 
Components Used:
1- Arduino Uno
1- Breadboard
3- LEDs
3-220 ohm resistors
7- wires
Code: 

Description: 
In this lab exercise, I played with PWM in order to create an RGB color diffusor. In order to spread out the sharp LED lights more and to smoothen them, I used cotton and Fell paper (tracing paper) over it. In order to increase the brightness of lights in my diffusor, the command to be entered is colorCode '+/-'. For example, r+ would increase the brightness of the red LEd by 50%. Similary, g- would decrease the brightness of the green LED by 50%.
Components:
Arduino Board

Approach

/* 

 * I262 - Assingment 2

 * ---------------

 * Function : Key press controls the brightness of R,G,B LEDs 

 * Date : 9.24.2013

 * Author : Suhaib Saqib Syed

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

 * http://todbot.com/

 */

char serInString[10];  // array that will hold the different bytes of the string. 100=100characters;

DESCRIPTION
This lab covered digital input, output, and designing your own diffuser. I started by taking the serial input code provided by the class and editing it so that it changes the different lights depending on what the user presses. For example, the red light will increase in increments of 10% for every "r" keystroke the user enters in the serial port. Once the color brightness is maxed out, pressing the corresponding color code again brings it back to 0 and the light will turn off.