Little pattern generator for Arduino-controlled Christmas lights

XmasLights.c

// Christmas light controller
// Drives three TRIAC channels for lights hung on outside of house

// Kenneth Finnegan, 2010
// kennethfinnegan.blogspot.com

#define ROOFL  12
#define ROOFR  11
#define WINDOW  13

void setup() {
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
  
  randomSeed(analogRead(0));
  
  int i;
  
  // Debug pattern to check channel numbers
  for (i= 0; i<5; i++) {
    digitalWrite(ROOFR, LOW);
    digitalWrite(ROOFL, LOW);
    digitalWrite(WINDOW, LOW);
    delay(500);
    digitalWrite(WINDOW, HIGH);
    delay(500);
    digitalWrite(ROOFL, HIGH);
    delay(500);
    digitalWrite(ROOFR, HIGH);
    delay(500);
  }
}

void loop() {
  int mode = random(32);
  int i, j;
  j = random(10) + 5;
  //mode = 8;
  
  switch (mode) {
    case 1:
    case 7:
      for (i=0; i<j; i++) {
        digitalWrite(WINDOW, HIGH);
        delay(700);
        digitalWrite(ROOFR, LOW);
        delay(300);
        digitalWrite(ROOFL, HIGH);
        delay(700);
        digitalWrite(WINDOW, LOW);
        delay(300);
        digitalWrite(ROOFR, HIGH);
        delay(700);
        digitalWrite(ROOFL, LOW);
        delay(300);
      }
      break;
      case 2:
      for (i=0; i<j; i++) {
        digitalWrite(WINDOW, HIGH);
        digitalWrite(ROOFR, LOW);
        delay(250);
        digitalWrite(ROOFL, HIGH);
        digitalWrite(WINDOW, LOW);
        delay(250);
        digitalWrite(ROOFR, HIGH);
        digitalWrite(ROOFL, LOW);
        delay(250);
      }
      break;
      case 3:
      for (i=0; i<4; i++) {
        digitalWrite(WINDOW, HIGH);
        digitalWrite(ROOFL, HIGH);
        digitalWrite(ROOFR, HIGH);
        delay(1000);
        digitalWrite(WINDOW, LOW);
        digitalWrite(ROOFL, LOW);
        digitalWrite(ROOFR, LOW);
        delay(500);
      }
      break;
      case 4:
        digitalWrite(WINDOW, HIGH);
        for (i=0; i<j; i++) {
          digitalWrite(ROOFR, HIGH);
          digitalWrite(ROOFL, LOW);
          delay(500);
          digitalWrite(ROOFR, LOW);
          digitalWrite(ROOFL, HIGH);
          delay(500);
        }
      break;
      case 5:
        for (i=0; i<j*3; i++) {
          digitalWrite(11 + random(3), random(2));
          delay(random(1000) + 500);
        }
      break;
      case 6:
      for (i= 0; i<5; i++) {
        digitalWrite(ROOFR, LOW);
        digitalWrite(ROOFL, LOW);
        digitalWrite(WINDOW, LOW);
        delay(500);
        digitalWrite(WINDOW, HIGH);
        delay(500);
        digitalWrite(ROOFL, HIGH);
        delay(500);
        digitalWrite(ROOFR, HIGH);
        delay(500);
      }
      break;
      case 8:
      digitalWrite(WINDOW, HIGH);
      for (i=0; i<j/2; i++) {
        digitalWrite(ROOFL, HIGH);
        delay(100);
        digitalWrite(ROOFL, LOW);
        delay(800);
        digitalWrite(ROOFR, HIGH);
        delay(100);
        digitalWrite(ROOFR, LOW);
        delay(800);
      }
      break;
      case 9:
      case 10:
      digitalWrite(WINDOW, HIGH);
      digitalWrite(ROOFR, HIGH);
      digitalWrite(ROOFL, HIGH);
      delay(20000);
      break;
      
    default:
      digitalWrite(ROOFL, HIGH);
      digitalWrite(ROOFR, HIGH);
      for (i=0; i<10; i++) {
        digitalWrite(WINDOW, HIGH);
        delay(1000);
        digitalWrite(WINDOW, LOW);
        delay(1000);
      }
      break;
  }
}