LCD-LED-Controller

#include <LiquidCrystal.h>

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;

//LED
int green, yellow, red, ticks, button_val;
boolean red_on, yellow_on, green_on = false;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  init();
  Serial.begin(9600);
  Serial.println("Starting!");
  delay(20);

  // set up the LCD's number of columns and rows:
  lcd.begin(16,2);
  int col = 0; //collumn to write in!

  //greeting:
  String greeting = "Hello, Julian!";
  //fade-in:
  while ((col < 16) && (col < greeting.length())) {
    lcd.setCursor(col, 0);
    lcd.print(greeting.charAt(col));
    delay(200);
    col++;
  }

  delay(2000);
  //fade-out
  col = 15;
  while (col >= 0) {
    lcd.setCursor(col, 0);
    lcd.print(" ");
    delay(200);
    col--;
  }

  //main-display:
  //fancy-firstline fade-in:
  String first_line = "Current state: ";
  String second_line = "G: 0| Y: 0| R: 0";
  col = 0;
  while ((col < 16) && (col < first_line.length())) {
    lcd.setCursor(col, 0);
    lcd.print(first_line.charAt(col));
    delay(200);
    col++;
  }

  col = 0;
  while ((col < 16) && (col < second_line.length())) {
    lcd.setCursor(col, 1);
    lcd.print(second_line.charAt(col));
    delay(200);
    col++;
  }

  //LED:
  green = 8;
  yellow = 9;
  red = 10;
  pinMode(green, OUTPUT);
  pinMode(yellow, OUTPUT);
  pinMode(red, OUTPUT);

  //button:
  pinMode(A2, INPUT);

  //loop:
  while (1) {
    int b = Serial.read(); //funny, you can't just use int OR byte, bc byte and int have different ranges. Use int to get the ASCII-Value correctly (byte is from 0 - 255; so -1 [nothing] reads 255 instead of -1)
    button_val = digitalRead(A2);

    if (((b == -1) || (b == 32) || (b == 10)) && (button_val == 0)) { //nothing or Space or NEW LINE -> Ignore and don't print (reduces spam)
      continue;
    }
    char input = char(b);
    //check "nothing" again, since the button could be pressed. This would result in a print of '?', since the upper break will not kick in.
    if ((b != -1)) {
      Serial.println(input);
    }

    //check if the bytes are something we want
    if ((input == 'r') || (input == 'R')) {
      switch_red();
    }
    else if ((input == 'y') || (input == 'Y')) {
      switch_yellow();
    }
    else if ((input == 'g') || (input == 'G')) {
      switch_green();
    }
    //button pressed?
    else if (button_val == 1) {
      int to_switch = random(3);
      Serial.println(to_switch);
      if (to_switch == 0) {
         switch_green();
      } else if (to_switch == 1) {
        switch_yellow();
      } else if (to_switch == 2) {
        switch_red();
      }
    }
    delay(500);
  }
}
void switch_red() {
  lcd.setCursor(15, 1);
  if (red_on) {
    digitalWrite(red, LOW);
    lcd.print("0");
    red_on = false;
  } else {
    digitalWrite(red, HIGH);
    lcd.print("1");
    red_on = true;
  }
}

void switch_yellow() {
  lcd.setCursor(9,1);
  if (yellow_on) {
    digitalWrite(yellow, LOW);
    lcd.print("0");
    yellow_on = false;
  } else {
    digitalWrite(yellow, HIGH);
    lcd.print("1");
    yellow_on = true;
  }
}

void switch_green() {
  lcd.setCursor(3,1);
  if (green_on) {
    digitalWrite(green, LOW);
    lcd.print("0");
    green_on = false;
  } else {
    digitalWrite(green, HIGH);
    lcd.print("1");
    green_on = true;
  }
}