#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>


#define SCREEN_WIDTH 128 // display display width,  in pixels
#define SCREEN_HEIGHT 64 // display display height, in pixels

#define SENSOR_PIN 4   // pin sensor DS18B20
#define BUZZER_PIN 5   // pin buzzer

#define display_RESET     -1 // Reset pin 
#define SCREEN_ADDRESS 0x3C ///address i2c oled 
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, display_RESET);

OneWire oneWire(SENSOR_PIN);         // setup a oneWire 
DallasTemperature tempSensor(&oneWire); // pass oneWire 



unsigned long previousMillis = 0;

String tempString,tempString1;
float Alarm = 40;     // Alarm
float tempCelsius;


void setup() {
  Serial.begin(9600);
  pinMode(BUZZER_PIN,OUTPUT);
  digitalWrite(BUZZER_PIN,LOW);

  // initialize display display with address 0x3C for 128x64
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true);
  }

  delay(2000);                     // wait for initializing
  display.clearDisplay();          // clear display

  display.setTextSize(1);          // text size
  display.setTextColor(WHITE);     // text color
  
  display.clearDisplay();
  display.drawRect(0, 0, 128, 64, WHITE);
  display.drawRect(2, 2, 124, 60, WHITE);
  display.display();
  displayDisplayCenter("VERTEX TECHNOLOGIES", 4);
  displayDisplayCenter("TEMPERATURA", 18);
  displayDisplayCenter("TESTE SENSOR 18B20",53);

  display.setTextSize(2);
  display.setCursor(0, 35);        // position to display

  tempSensor.begin();     // initialize the sensor
  tempString.reserve(10); // to avoid fragmenting memory when using String


  

  
}

void loop() {
  tempSensor.requestTemperatures();             // send the command to get temperatures
  tempCelsius = tempSensor.getTempCByIndex(0);  // read temperature in Celsius

  
  tempString  = String(tempCelsius, 2); // two decimal places
  tempString += (char)247;
  tempString += "C";
  
  //biar ketumpuk hitam dulu jika suhu nya berubah
  if(tempString != tempString1)
  {
  display.setTextColor(BLACK);
  displayDisplayCenter(tempString1,32);
  }
  
  tempString1= tempString; 
  Serial.println(tempString); // print the temperature in Celsius to Serial Monitor
  
  //lanjut tulis warna putih
  display.setTextColor(WHITE);
  displayDisplayCenter(tempString,32);


  if( tempCelsius >= Alarm)  //cek alarm vs buzzer
   {

    digitalWrite(BUZZER_PIN,HIGH);
    delay(200);
    digitalWrite(BUZZER_PIN,LOW);
    delay(50);
   }
  
  else digitalWrite(BUZZER_PIN,LOW);
   
}

//function agar tulisan rata tengah (center)

void displayDisplayCenter(String text, int posisi) {
  int16_t x1;
  int16_t y1;
  uint16_t width;
  uint16_t height;

  display.getTextBounds(text, 0, 0, &x1, &y1, &width, &height);

  display.setCursor((SCREEN_WIDTH - width) / 2, posisi);
  display.println(text); // text to display
  display.display();
}