Description
After getting the light to work with repeated key presses, I exteded the behavior to include all the letters, the basic premise being that while it is often the case that rock concerts have fancy light shows, poetry readings tend not to. Or put another way, I have seen many more color/light visualizations of music/sound than I have for text. So to remedy that we have a (small scale) haiku light show implemented with three LEDs, a tube made from taped together index cards (2) some reflective aluminium foil inside, and a puff of cotton, reminiscent of one of those little troll dolls from the 80's. A line of the poem is entered in the serial monitor, and the color changes as a result of each character entered. Poems tested (all haiku) exhibited different tendencies, some started green but turned out to be more blue at the end, you get the idea. I suppose it is possible that reflecting on this one might consider the color of text as one is in the process of composing it thus extending the expressive range of the compisition.
Materials
- Index cards (2)
- Aluminium Foil
- Tape
- 1/3 of a Cotton Ball
- LEDs (Red, Green, and Blue)
- Resistors and Wires
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".
* 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>
*
* Adapted 12 Sept 2009
* Noah Kersey <kersey@ischool.berkeley.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 = 0;
int greenValue = 0;
int blueValue = 0;
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);
} else if (colorCode == 'p') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'q') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 's') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 't') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'u') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'v') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'w') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'x') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'y') {
redValue = (redValue + 10) % 255;
analogWrite(redPin, redValue);
Serial.print("setting color r to ");
Serial.println(redValue);
} else if (colorCode == 'z') {
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);
} else if (colorCode == 'h') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'i') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'j') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'k') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'l') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'm') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'n') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == 'o') {
greenValue = (greenValue + 10) % 255;
analogWrite(greenPin, greenValue);
Serial.print("setting color g to ");
Serial.println(greenValue);
} else if (colorCode == ' ') {
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'|| 'a' || 'c' || 'd' || 'e' || 'f' || '.') {
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;
}
}
