const int btn_emergency = 12;
const int btn_k3        = 14;
const int btn_pendek    = 27;
const int btn_panjang   = 26;

const int led_emergency = 13;
const int led_k3        = 33;
const int led_pendek    = 32;
const int led_panjang   = 2;

int led_emergency_state = LOW;
int led_k3_state        = LOW;
int led_pendek_state    = LOW;
int led_panjang_state   = LOW;

int last_button_emergency_state;
int last_button_k3_state;
int last_button_pendek_state;
int last_button_panjang_state;

int current_button_emergency_state;
int current_button_k3_state;
int current_button_pendek_state;
int current_button_panjang_state;

void setup() {
  Serial.begin(9600);               // initialize serial

  pinMode(btn_emergency, INPUT_PULLUP);
  pinMode(btn_k3, INPUT_PULLUP);
  pinMode(btn_pendek, INPUT_PULLUP);
  pinMode(btn_panjang, INPUT_PULLUP);

  pinMode(led_emergency, OUTPUT);
  pinMode(led_k3, OUTPUT);
  pinMode(led_pendek, OUTPUT);
  pinMode(led_panjang, OUTPUT);

  current_button_emergency_state = digitalRead(btn_emergency);
  current_button_k3_state        = digitalRead(btn_k3);
  current_button_pendek_state    = digitalRead(btn_pendek);
  current_button_panjang_state   = digitalRead(btn_panjang);
}
void loop() {
  last_button_emergency_state   = current_button_emergency_state;
  last_button_k3_state          = current_button_k3_state;
  last_button_pendek_state      = current_button_pendek_state;
  last_button_panjang_state     = current_button_panjang_state;

  current_button_emergency_state = digitalRead(btn_emergency);
  current_button_k3_state        = digitalRead(btn_k3);
  current_button_pendek_state    = digitalRead(btn_pendek);
  current_button_panjang_state   = digitalRead(btn_panjang);

  if(last_button_emergency_state == HIGH && current_button_emergency_state == LOW) {
    Serial.println("EMERGENCY!! CEPAT EVAKUASI");
    // toggle state of LED
    led_emergency_state = !led_emergency_state;
    // control LED arccoding to the toggled state
    digitalWrite(led_emergency, led_emergency_state);
    delay(100); 
  }

  if(last_button_k3_state == HIGH && current_button_k3_state == LOW) {
    Serial.println("K3 DISIARKAN");
    // toggle state of LED
    led_k3_state = !led_k3_state;
    // control LED arccoding to the toggled state
    digitalWrite(led_k3, led_k3_state); 
    delay(100);
  }

  if(last_button_pendek_state == HIGH && current_button_pendek_state == LOW) {
    Serial.println("BEL PENDEK DIBUNYIKAN");
    // toggle state of LED
    led_pendek_state = !led_pendek_state;
    // control LED arccoding to the toggled state
    digitalWrite(led_pendek, led_pendek_state); 
    delay(100);
  }

  if(last_button_panjang_state == HIGH && current_button_panjang_state == LOW) {
    Serial.println("BEL PANJANG DIBUNYIKAN");
    // toggle state of LED
    led_panjang_state = !led_panjang_state;
    // control LED arccoding to the toggled state
    digitalWrite(led_panjang, led_panjang_state); 
    delay(100);
  }
}