Written by Joe Schembrie aka Engineer Zero.
In the public domain.
No attribution necessary.
Alter as you see fit.

Controls an RGB LED in multiple modes. A push button changes
the mode and a potentiometer is used to adjust intensity,
rate, and color.

***IMPORTANT ByTheWay:

I used a common anode RGB, for which
analogWrite() goes HIGH for 0 and LOW for 255. You'll have
to revise your code accordingly if you use a common cathode RGB.

Lighting Mode Descriptions:

0 OFF
1 Candle
2 Red
3 Blue
4 Green
5 Tricolor
6 Strobe
7 Pure White
8 Broken Light
9 Yellow flashing (caution)
10 Psychedelic
11 Pulse

See my blog, http://engineerzero.blog for more fun stuff.

*/

// here are the pin number assignments

int blue = 11;
int green = 10;
int red = 9;
int potpin = 3; // the pin the potentiometer is on
int button = 7; // the pin the button is on.

// various variables

int potval = 0; // adjusts for magnitude and rate
int choice = 0; // your mode selection

// these 'prev' values are for the psychedelic choice

long rprev = 128;
long gprev = 128;
long bprev = 128;

void setup() {

// initialize the pwm pins as outputs.
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
pinMode(button,INPUT);

analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255);

// seed the random number generator
randomSeed(100);

}

void loop() {

// read the pushbutton to see if it's been pushed
int val;
val = digitalRead(button);

// val = HIGH means the button has been pushed
// and the mode is to be changed.

// SELECT CHOICE //////////////////////////////////////////////////
if(val==HIGH){
choice = choice + 1;

analogWrite(blue,255);
analogWrite(green,255);
analogWrite(red,255);
delay(500);

// indicate mode transition with blue flashes
for(int i = 0; i<5; i++){
analogWrite(blue,125);
delay(20);
analogWrite(blue,255);
delay(40);
}

delay(500);

// change this if you want more modes

if (choice == 12){
choice = 0;
}
}

//TIME TO LIFT BUTTON //////////////////////////////
// (for debounce)

while (val == HIGH){
delay(100);
val = digitalRead(button);
}

//////////////////////////////

// read the potentiometer value
potval = analogRead(potpin);

// OFF
if(choice==0){
analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255);
}

// CANDLE FLAME
if(choice==1){
flicker();
}

// RED

if(choice==2){
analogWrite(red,255 - potval/4);
analogWrite(green,255);
analogWrite(blue,255);

}

// GREEN
if(choice==3){
analogWrite(red,255);
analogWrite(green,255 - potval/4);
analogWrite(blue,255);
}

// BLUE

if(choice==4){
analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255 - potval/4);
}

// tricolor
if(choice==5){
analogWrite(red,255);
analogWrite(blue,255);
analogWrite(green,255);
int tricolor;
for(int j = 0; j<4; j++){
if(j==0){
tricolor = red;
}
if(j==1){
tricolor = green;
}
if(j==2){
tricolor = blue;
}
analogWrite(tricolor,0);
delay(522-potval/2);
analogWrite(tricolor,255);
delay(522-potval/2);

}

} // end of tricolor

// STROBE

if(choice==6){
analogWrite(red,0);
analogWrite(green,0);
analogWrite(blue,0);
delay(10);
analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255);
delay(1023-potval);
}

//this is white
if(choice==7){
analogWrite(red,255 - potval/4);
analogWrite(green,255 - potval/4);
analogWrite(blue,255 - potval/4);
}

// Oh no, your light is broken!
if(choice==8){
int mag8 = random(0,255);
analogWrite(red,mag8);
analogWrite(green,mag8);
analogWrite(blue,mag8);
int d8 = random(0,100);
delay(d8);
if(random(0,30)==0){
analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255);
delay(500);
}
}

// Caution-warning yellow flashing light
if(choice==9){
analogWrite(red,0);
analogWrite(green,125);
analogWrite(blue,255);
delay(100);
analogWrite(red,255);
analogWrite(green,255);
analogWrite(blue,255);
delay(1200);

}

// Psychedelic
if(choice==10){

// When tweaking code, careful with variable types.

long rnew = random(256);
long gnew = random(256);
long bnew = random(256);
long rval;
long gval;
long bval;

for(int i; i<101; i++){
rval = rprev + long(i *(rnew - rprev)/100);
analogWrite(red,rval);
delay(5);
}
for(int i; i<101; i++){
gval = gprev + long(i *(gnew - gprev)/100);
analogWrite(green,gval);
delay(5);
}
for(int i; i300){
p = blue;
}
if(potval>600){
p = green;
}
for(int i = 0; i<256; i++){
analogWrite(p,255-i);
delay(4);
}
for(int i = 0; i<256; i++){
analogWrite(p,i);
delay(4);
}
delay(500);

} // end of choice 11

} // end of loop, loop, loopy-doop!

////////////////////////////////////////////////////////////

void flicker(){

// makes a flickering candle light

int k = random(0,100);
potval = analogRead(potpin);
float p = float(potval)/1023;

int rmag = 255 - (15 + 155 * k/100)*p;
int gmag = 255 - (10 + 55 * k/100)*p;

analogWrite(red,rmag);
analogWrite(green,gmag);

int d = 50+300 * random(0,100)/300;

delay(d);

}

////////////////////////////////////////////////

void tricolor(){

// transitions between red, blue, and green lights

analogWrite(red,255);
analogWrite(blue,255);
analogWrite(green,255);

analogWrite(red,0);
delay(500);
analogWrite(red,255);
delay(500);

analogWrite(green,0);
delay(500);
analogWrite(green,255);
delay(500);

analogWrite(blue,0);
delay(500);
analogWrite(blue,255);
delay(500);

}