Lab 2: Diffuser & Re-programming

Assignment: Digital I/O with Arduino Boards + Diffuser

Collaborators:

I had a lot of trouble attempting to re-write the program to include commands for increasing the LEDs' intensity based upon multiple r, g, or b inputs. After speaking with Professor Ryokai & Kenghao, I feel much more confident in understanding the modified code, but would still be unable to write it myself. I did manage to amend the code to respond to the command "purple" & adjust the lights accordingly. Here is that code:

/*

* 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

*

* Created 18 October 2006

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

* http://todbot.com/

*/

 

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

 

void setup() {

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

pinMode(greenPin, OUTPUT);

pinMode(bluePin,  OUTPUT);

Serial.begin(9600);

analogWrite(redPin,   127);   // set them all to mid brightness

analogWrite(greenPin, 127);   // set them all to mid brightness

analogWrite(bluePin,  127);   // set them all to mid brightness

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

Serial.println("or enter 'p' for purple");

}

 

void loop () {

// clear the string

memset(serInString, 0, 100);

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

readSerialString(serInString);

 

colorCode = serInString[0];

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

colorVal = atoi(serInString+1);{

if(colorVal != 0) {

Serial.print("setting color ");

Serial.print(colorCode);

Serial.print(" to ");

Serial.print(colorVal);

Serial.println();

serInString[0] = 0;

}    // indicates we've used this string

 

if(colorCode == 'r')

analogWrite(redPin, colorVal);

else if(colorCode == 'g')

analogWrite(greenPin, colorVal);

else if(colorCode == 'b')

analogWrite(bluePin, colorVal);

else if(colorCode == 'p') {

analogWrite(redPin, 155);

analogWrite(bluePin, 75);

analogWrite(greenPin, 0);

}

 

 

}

 

 

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++;

}

}

For my diffuser, I stuffed a thick glass bottle with cotton balls. The photo shows the output to the input "purple."