const int RS = 23, EN = 22, D4 = 19, D5 = 18, D6 = 5, D7 = 4;
// Fungsi untuk set binner yang dikirim ke port data
void lcd_port(char a){
  digitalWrite(D4, LOW);
  digitalWrite(D5, LOW);
  digitalWrite(D6, LOW);
  digitalWrite(D7, LOW);
  if(a & 0x01) digitalWrite(D4, HIGH);
  if(a & 0x02) digitalWrite(D5, HIGH);
  if(a & 0b0100) digitalWrite(D6, HIGH);
  if(a & 0b1000) digitalWrite(D7, HIGH);
}

void lcd_disableCursor() {
  lcd_cmd(0b0000);
  lcd_cmd(0b1100);   // Display ON, cursor OFF, blinking OFF
}

// Fungsi pengiriman perintah ke LCD
void lcd_cmd(char b){
  digitalWrite(RS, LOW);
  lcd_port(b);

  delayMicroseconds(40);
  digitalWrite(EN, HIGH);
  delayMicroseconds(40);
  digitalWrite(EN, LOW);
}

// Fungsi membersihkan tampilan
void lcd_clear(){
  lcd_cmd(0x00);
  lcd_cmd(0x01);
} 

// Fungsi untuk setting di awal
void lcd_init(){
  pinMode(RS, OUTPUT);
  pinMode(EN, OUTPUT);
  pinMode(D4, OUTPUT);
  pinMode(D5, OUTPUT);
  pinMode(D6, OUTPUT);
  pinMode(D7, OUTPUT);

  lcd_cmd(0b0010);
  lcd_cmd(0b0010);
  lcd_cmd(0b1000);

  lcd_cmd(0b0000);
  lcd_cmd(0b1110);

  lcd_cmd(0b0000);
  lcd_cmd(0b0110);
}

void lcd_setCursor(char baris, char kolom){
  char x,y;

  if(baris == 0){
    x = 0x08;
    y = kolom;
  }

  else{
    x = 0x0C;
    y = kolom;
  }

  lcd_cmd(x);
  lcd_cmd(y);
}

void writeChar(char c){
  digitalWrite(RS, HIGH);
  
  lcd_port(c >> 4);
  delayMicroseconds(40);
  digitalWrite(EN, HIGH);
  delayMicroseconds(40);    
  digitalWrite(EN, LOW);

  lcd_port(c & 0x0F);
  delayMicroseconds(40);      
  digitalWrite(EN, HIGH);
  delayMicroseconds(40);
  digitalWrite(EN, LOW);
}

void writeString(const char* str){
  while (*str) {
    writeChar(*str);
    str++;
  }
}

void setup() {
  // put your setup code here, to run once:
  lcd_init();
  lcd_disableCursor();

  lcd_setCursor(1,12);
  writeChar('F');

  lcd_setCursor(0,3);
  writeString("ELEKTRONIKA");
  lcd_setCursor(1,4);
  writeString("KELAS : ");
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}

// Tugas:
// Kembangkan fungsi writeChar dan writeString sehingga memudahkan untuk menampilkan tulisan di LCD