#include <LiquidCrystal_I2C.h>

#define PARK_PIN 17
#define DIR_PIN 4
#define STEP_PIN 16
#define RSW_PIN 5
#define LED_PIN 15
#define MSW_PIN 23
#define ENCODER_CLK_PIN 18
#define ENCODER_DT_PIN 19

LiquidCrystal_I2C lcd(0x27, 16, 2);

int deg = 0;
int trg = 0;
const float BETA = 3950;
int mode = 0;
int rspd = 50;
int spd = 105;

void setup() {
  lcd.init();
  lcd.backlight();
  
  pinMode(STEP_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(MSW_PIN, INPUT_PULLUP);
  pinMode(PARK_PIN, INPUT_PULLUP);
  pinMode(RSW_PIN, INPUT_PULLUP);
  pinMode(ENCODER_CLK_PIN, INPUT);
  pinMode(ENCODER_DT_PIN, INPUT);
  
  attachInterrupt(digitalPinToInterrupt(ENCODER_CLK_PIN), readEncoder, FALLING);
}

void readEncoder() {
  int dtValue = digitalRead(ENCODER_DT_PIN);

  if (mode == 0) {
    trg += (dtValue == HIGH) ? 1 : -1;
  } 
  else if (mode == 1) {
    rspd += (dtValue == HIGH) ? 1 : -1;
  }
}

void loop() {
  if (digitalRead(MSW_PIN) == LOW) {
    mode++;
    lcd.clear();
  }
  
  if (mode >= 3) {
    mode = 0;
  }
  
  if (mode == 0) {
    int analogValue = analogRead(2);
    float celsius = 1 / (log(1 / (4095. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
    
    if (trg >= 360) {
      trg -= 360;
    }
    
    if (trg <= -1) {
      trg += 360;
    }

    if (celsius > 78) {
      lcd.setCursor(0, 0);
      lcd.print("HIGH TEMPERATURE");
      lcd.setCursor(0, 1);
      lcd.print(celsius);
      lcd.print(" Celsius");
    }

    if (digitalRead(RSW_PIN) == LOW) {
      lcd.clear();
      lcd.print("Moving to: ");
      lcd.print(trg);
      lcd.print(char(223));
      digitalWrite(LED_PIN, HIGH);

      while (trg > deg) {
        digitalWrite(DIR_PIN, HIGH);
        digitalWrite(STEP_PIN, HIGH);
        delay(spd);
        digitalWrite(STEP_PIN, LOW);
        digitalWrite(DIR_PIN, LOW);
        deg++;
      }

      while (trg < deg) {
        digitalWrite(STEP_PIN, HIGH);
        delay(spd);
        digitalWrite(STEP_PIN, LOW);
        deg--;
      }

      lcd.clear();
      digitalWrite(LED_PIN, LOW);
    }

    if (digitalRead(PARK_PIN) == LOW) {
      lcd.clear();
      lcd.print("Parking...");

      while (0 > deg) {
        digitalWrite(DIR_PIN, HIGH);
        digitalWrite(STEP_PIN, HIGH);
        delay(spd);
        digitalWrite(STEP_PIN, LOW);
        digitalWrite(DIR_PIN, LOW);
        deg++;
      }

      while (0 < deg) {
        digitalWrite(STEP_PIN, HIGH);
        delay(spd);
        digitalWrite(STEP_PIN, LOW);
        deg--;
      }

      lcd.clear();
    }

    lcd.setCursor(0, 0);
    lcd.print("Current: ");
    lcd.print(deg);
    lcd.println(char(223));
    lcd.setCursor(0, 1);
    lcd.print("Target: ");
    lcd.print(trg);
    lcd.println(char(223));
    delay(100);
  } 
  else if (mode == 1) {
    rspd = constrain(rspd, 0, 100);
    
    if (millis() / 500 % 2 == 0) {
      lcd.clear();
    }

    spd = map(rspd, 0, 100, 200, 10);
    
    lcd.setCursor(0, 0);
    lcd.print("Speed: ");
    lcd.print(rspd);
    lcd.print("%");
    lcd.setCursor(0, 1);
    lcd.print("Raw: ");
    lcd.print(spd);
    lcd.print("ms");
    delay(100);
  } else {
    int analogValue = analogRead(2);
    float celsius = 1 / (log(1 / (4095. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(celsius);
    lcd.setCursor(0, 1);
    lcd.print(millis());
    delay(100);
  }
}