#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <PID_v1.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define tempSensor A0
#define iron 10
#define LED 9
const int pinCLK = 2;
const int pinDT = 3;
const int pinSW = 4;
bool IronState = false;
int minTemp = 27;
int maxTemp = 525;
int minADC = 252;
int maxADC = 751;
int currentTemp = 0;
int Temp = 0;
int lcdInterval = 500; 
int previousMillis = 0; 

volatile int setTemp = 0;
int currentStateCLK;
int lastStateCLK;
unsigned long lastButtonPress = 0;

double Setpoint, Input, Output;
double Kp = 2.5, Ki = 0.01, Kd = 0.02;
PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);

void setup() {
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("D@niel Prodution Inc");
  display.display();
  delay(3000);
  display.clearDisplay();
  pinMode(pinCLK, INPUT);
  pinMode(pinDT, INPUT);
  pinMode(pinSW, INPUT_PULLUP);
  pinMode(tempSensor, INPUT);
  pinMode(iron, OUTPUT);
  pinMode(LED, OUTPUT);
  setTemp = 350;
 
  display.setCursor(0, 10);
  display.print("OFF");
  display.display();
  
  myPID.SetMode(AUTOMATIC);
  myPID.SetOutputLimits(0, 255);  
  attachInterrupt(digitalPinToInterrupt(pinCLK), updateEncoder, CHANGE);
  lastStateCLK = digitalRead(pinCLK);
}
void loop() {
  int buttonState = digitalRead(pinSW);
  currentTemp = map(analogRead(tempSensor), minADC, maxADC, minTemp, maxTemp);
  Input = currentTemp;
  Setpoint = setTemp;
  Temp = currentTemp;
  display.setCursor(0, 10);
   display.setTextSize(2);
  display.print("SET :");
  display.print(setTemp);
  display.print((char)223);
  display.print("C ");
  display.setTextSize(1);
  display.display();
  myPID.Compute();
  myPID.SetTunings(Kp, Ki, Kd);
  if (IronState == LOW) {Output = 0; }
  if (setTemp > 525) { setTemp = 525; }
  if (setTemp < 35) { setTemp = 35; }
  analogWrite(iron, Output);
  analogWrite(LED, Output);
  if (buttonState == LOW) {
    if (millis() - lastButtonPress > 300) {
      IronState = !IronState;
      digitalWrite(iron, IronState ? HIGH : LOW);
      display.setCursor(0, 10);
      if (IronState == LOW) {
          display.clearDisplay();
          display.display();
          display.print("OFF"); 
         }

      if (IronState == HIGH) {
          display.clearDisplay();
          display.display();
          display.print("ON ");
          }

      lastButtonPress = millis();
    }
  }
  unsigned long currentMillis = millis(); 
  if (currentMillis - previousMillis >= lcdInterval){
    previousMillis = currentMillis;
    display.clearDisplay();
    display.display();
    display.setCursor(0, 20);
    display.print("Ferro:");
    display.print(Temp);
    display.print((char)248);
    display.print("C ");
    display.setCursor(0, 20);
    if (IronState == HIGH) {display.print("ON ");}
    if (IronState == LOW) {display.print("OFF");}
  } 
}

void updateEncoder() {
  currentStateCLK = digitalRead(pinCLK);
  if (currentStateCLK != lastStateCLK && currentStateCLK == HIGH) {
    int currentStateDT = digitalRead(pinDT);
    if (currentStateDT != currentStateCLK) {
      setTemp++;
    } else {
      setTemp--;
    }
  }
  lastStateCLK = currentStateCLK;
  
}