int state = 0;
int buzzstate = true;
const int led1 = 13;
const int led2 = 12;
const int led3 = 11;
const int led4 = 10;
const int led5 = 8;
const int buzz = 7;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(led5, OUTPUT);
  pinMode(buzz, OUTPUT);
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
  digitalWrite(led5, LOW);
  digitalWrite(buzz, LOW);
  Serial.begin(9600);
  Serial.println("Begin"); 
}


void beep(int sec){
  if (buzzstate) {
    digitalWrite(buzz, HIGH);
    delay(sec);
    digitalWrite(buzz, LOW);
    delay(sec);
  }
}


void loop() {
  if (Serial.available() > 0) { 
    state = Serial.read(); 

    switch (state) {
      case 'a': digitalWrite(led1, HIGH); beep(100); Serial.println("led1: OFF"); break;
      case 'b': digitalWrite(led1, LOW); beep(100); Serial.println("led1: ON"); break;
      case 'c': digitalWrite(led2, HIGH); beep(100); Serial.println("led2: OFF"); break;
      case 'd': digitalWrite(led2, LOW); beep(100); Serial.println("led2: ON"); break;
      case 'e': digitalWrite(led3, HIGH); beep(100); Serial.println("led3: OFF"); break;
      case 'f': digitalWrite(led3, LOW); beep(100); Serial.println("led3: ON"); break;
      case 'g': digitalWrite(led4, HIGH); beep(100); Serial.println("led4: OFF"); break;
      case 'h': digitalWrite(led4, LOW); beep(100); Serial.println("led4: ON"); break;
      case 'i': digitalWrite(led5, HIGH); beep(100); Serial.println("led5: OFF"); break;
      case 'j': digitalWrite(led5, LOW); beep(100); Serial.println("led5: ON"); break;
      case 'k': buzzstate = false; Serial.println("buzz: OFF"); break;
      case 'l': buzzstate = true; beep(500); Serial.println("buzz: ON"); break;
      default: break;
    }
  }
}