#include<Wire.h>
#include<Adafruit_GFX.h>
#include<Adafruit_SSD1306.h>

const int lebar   = 128;
const int tinggi  = 64;
const int reset   = 4;
Adafruit_SSD1306 oled(lebar, tinggi, &Wire, reset);

int El_A = 6;
int El_B = 7;
int El_M = 8;
int El_N = 9;

// char data ='-';         // isi angka 1, 2, 3, atau 4, atau bebas


void setup() {
  Serial.begin(9600);
  Serial.println("You can type numbers 1,0 or the charchter B or M");
  oled.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  oled.clearDisplay();
  oled.setTextColor(WHITE);
  oled.clearDisplay();
  oled.setTextSize(2, 3);
  oled.setCursor(10,10);
  oled.print("Elec : 90");
  oled.setTextSize(2);
  oled.setCursor(10,40);
  oled.print("prepare");
  oled.display();  
  pinMode(El_A ,  OUTPUT);
  pinMode(El_B ,  OUTPUT);
  pinMode(El_M ,  OUTPUT);
  pinMode(El_N ,  OUTPUT);
}

void loop(){
  if (Serial.available() > 0) 
  {
    char data = Serial.read();
    if (data == '0'){
      El_off();
      data = '-';
      tampil(data);
    }
    else {
      pilih(data);
    }
  }
}

void pilih(char data){
    switch (data) {
    case 'A':
      El_off();
      pilih_A();
      tampil(data);
      break;
    case 'B':
      El_off();
      pilih_B();
      tampil(data);
      break;
    case 'M':
      El_off();
      pilih_M();
      tampil(data);
      break;
    case 'N':
      El_off();
      pilih_N();
      tampil(data);
      break;
  }
}


void pilih_A(){
  digitalWrite(El_A, HIGH);
  Serial.println("you have pressed the number 1");
}

void pilih_B(){
  digitalWrite(El_B, HIGH);
}

void pilih_M(){
  digitalWrite(El_M, HIGH);
}

void pilih_N(){
  digitalWrite(El_N, HIGH);
}

void El_off(){
  digitalWrite(El_A, LOW);
  digitalWrite(El_B, LOW);
  digitalWrite(El_M, LOW);
  digitalWrite(El_N, LOW);
}

void tampil (char data) {
  oled.clearDisplay();
  oled.setTextColor(WHITE);
  oled.clearDisplay();
  oled.setTextSize(2, 3);
  oled.setCursor(10,10);
  oled.print("Elec : 90");
  oled.setTextSize(2);
  oled.setCursor(10,40);
  oled.print(data);
  oled.display(); 
}