Assignment: Digital I/O with Arduino Boards + Diffuser
Collaborators:
/*
* 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
*
* Adapted 15 September 2009
* Anuj Tewari
*
*/
//include support for manipulating strings.
#include <string.h>
int maxLength = 100;
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 = 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("There are two ways to adjust the light intensity:");
Serial.println("1. Fancy and Fast: use multiples; '+rrr' increases red by 75, and '-rggb' decreases red by 25, green by 50, and blue by 25");
Serial.println("2. Standard: specify values; 'r125' sets red to 125, and 'r35g55' sets red to 35 and green to 55");
Serial.println("enter color command :");
}
void loop () {
//read the serial port and create a string out of what you read
readSerialString();
//Or write your own function...
if(strlen(serInString) > 0){
handleInput();
}
//Erase anything left in the serial string, preparing it for the
//next loop
resetSerialString();
delay(100); // wait a bit, for serial data
}
void resetSerialString() {
for (int i = 0; i < maxLength; i++) {
serInString[i] = '\0';
}
}
//read a string from the serial and store it in an array
//you must supply the array variable
void readSerialString() {
int i = 0;
if(!Serial.available()) {
return;
}
while (Serial.available() && i < maxLength) {
serInString[i] = Serial.read();
i++;
}
}
int newColorValue(int colorValue, int increment){
colorValue = colorValue + increment;
if(colorValue < 0)
colorValue = 0;
else if(colorValue > 255)
colorValue = 255;
return colorValue;
}
//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 60 and green by 20.
void handleInput() {
int i = 0;
int increment = 0;
switch(serInString[0]){
case '-':
i++;
increment = -25;
break;
case '+':
i++;
increment = 25;
break;
default:
processNumericalCommands();
return;
}
//loop through the string (serInString)
//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 && serInString[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 = newColorValue(redValue, increment);
//If the character is g (green)...
} else if (colorCode == 'g') {
greenValue = newColorValue(greenValue, increment);
//If the character is b (blue)...
} else if (colorCode == 'b') {
blueValue = newColorValue(blueValue, increment);
}
//Move on to the next character in the string
//From here, the code continues executing from the "while" line above...
i++;
}
//Tell the user what we did
Serial.print("setting LED intensities r = ");
Serial.print(redValue);
Serial.print(", g = ");
Serial.print(greenValue);
Serial.print(", b = ");
Serial.println(blueValue);
analogWrite(redPin, redValue);
analogWrite(greenPin, greenValue);
analogWrite(bluePin, blueValue);
}
//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() {
int i = 0;
while (i < maxLength && serInString[i] != '\0') {
//read in the first character in the string
colorCode = serInString[i];
i++;
//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 + i) % 256;
Serial.print("setting color ");
Serial.print(colorCode);
Serial.print(" to ");
Serial.println(colorVal);
if(colorCode == 'r')
analogWrite(redPin, colorVal);
else if(colorCode == 'g')
analogWrite(greenPin, colorVal);
else if(colorCode == 'b')
analogWrite(bluePin, colorVal);
//skip past the numeric component
i++;
if(colorVal != 0){
while(colorVal > 10){
colorVal /= 10;
i++;
}
}
}
}
}
