Assignment: Digital I/O with Arduino Boards + Diffuser

Collaborators:

Description

For this assignment, I modified the sample code so that simply pressing "r" or "b" or "g" would increase the brightness by 10 (on the scale of 255).

Note: for some reason at the prompt, it loops over my instructions multiple times.  I tried for a long time to fix the problem, but couldn't quite seem to make it right.  But the functionality of the program still works.

Components Used

• 3 Light Emitting Diodes (LED)
• 3 Resistors
• One old glass globe from an old light
• Love

Arduino 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
*
* Alternate command structure is "<colorCode>", where "colorCode" is one of "r","g", or "b"
* for example: pressing "r" once increases the LED brightness by 10
*              pressing "r" 3x ("rrr"), increases the LED brightness by 30
pressing "bbg" increases the blue LED brightness by 20 and green by 10
* Created 18 October 2006
* copyleft 2006 Tod E. Kurt <tod@todbot.com
* http://todbot.com/
*
* Code adapted by David Rolnitzky, September 2009, with compliments and assistance to examples from classes in '07 and '08
*/

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 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,   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("You can change the brightness in 2 ways: By entering a color command, like 'r43', or by using multiple keystrokes like 'bbb' to increase blue");
Serial.println("You can enter a color command, like typing 'r43'");
Serial.println("Or, you can use multiple keystrokes like 'bbb' to increase blue by 30");
}

void loop () {
//read the serial port and create a string out of what you read
readSerialString(serInString, 100);

//reads commands of the form 'rrrb'
processRepeatKeyCommands(serInString, 100);

//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++;
}
}

//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;
}
}