#include <EEPROM.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);  //Device Address,N Charecter, LCD Lines
//SDA-> A4 SCL-> A5
int sensor_pin = A0;
int std_value = 0;
int sw_set = 2;  //Connect to Switch Set
int sw_up = 3;   //Connect to Switch UP
int sw_dwn = 4;  //Connect to Switch Down
int sw_ent = 5;  //Connect to Switch Enter
int purge = 6;   //For Solenoid
int feed = 7;    //For Solenoid
int bzr = 8;     //Buzzer
int max_limit = 70;
int min_limit = 10;
float pressure_value = 0;
//int sensor_Value = 0;
int cal_factor = 0;
int set_mode = 0;
int threshold = 2;
int unit_mode = 1;
int inf_delay = 1000;
int key_delay = 300;
int run_mode = 0;  // run_mode=0 Standby
int set_value = 0;
String disp_string[4] = { "  Tyre Inflator", "Set Pressure", "-", "-" };
String unit_label[3] = { "BAR", "Kg/cm2", "PSI" };
void setup() {
  // declare the ledPin as an OUTPUT:
  //pinMode(ledPin, OUTPUT);
  pinMode(purge, OUTPUT);
  pinMode(feed, OUTPUT);
  pinMode(bzr, OUTPUT);
  pinMode(sw_up, INPUT_PULLUP);
  pinMode(sw_dwn, INPUT_PULLUP);
  pinMode(sw_set, INPUT_PULLUP);
  pinMode(sw_ent, INPUT_PULLUP);
  digitalWrite(purge, HIGH);
  digitalWrite(feed, HIGH);
  digitalWrite(bzr, HIGH);

  Serial.begin(9600);
  init_settings();
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(6, 0);
  lcd.print("Welcome");
  lcd.setCursor(4, 1);
  lcd.print("Automatic");
  lcd.setCursor(2, 2);
  lcd.print("Tyre Inflator");
  delay(3000);
  lcd.clear();
  disp_string[1] = "Set PV:" + String(std_value) + unit_label[unit_mode];
  disp_string[2] = "Press Enter";
  disp_string[3] = "To Start Inflating";
  display();
}

void loop() {
  pressure_value = read_sensor(unit_mode, cal_factor);  //Mode,Calibration Factor
  if (digitalRead(sw_set) == LOW) {
    delay(key_delay);
    if (run_mode > 3) {  //0=Standby,1=Working, 2=Pressure Setting,3=Unit Setting,4=Calibration
      run_mode = 0;
    } else {
      run_mode += 1;
    }
    lcd.clear();
    display();
  }


  switch (run_mode) {
    case 0:
      disp_string[0] = "Stand By";
      //standby();
      break;
    case 1:
      disp_string[0] = "Inflate";
      // inflate(std_value);
      break;
    case 2:  //Pressure Setting
      disp_string[0] = "Pressure Setting..";
      set_value = std_value;
      max_limit = 100;
      min_limit = 10;
      break;
    case 3:  //Unit Setting
      disp_string[0] = "Unit Setting...";
      disp_string[1] = "Mes. Unit:" + unit_label[unit_mode];
      disp_string[2] = "____________________";
      disp_string[3] = "Press SET To Stop   ";
      set_value = unit_mode;
      max_limit = 3;
      min_limit = 0;
      break;
    case 4:  //Sensor Calibration
      disp_string[0] = "Sensor Calibration";
      int x = analogRead(sensor_pin);  //Read ADC Value
      pressure_value = read_sensor(unit_mode, cal_factor);
      set_value = cal_factor;
      max_limit = 25;
      min_limit = 0;
      disp_string[1] = "Cal. Factor:" + String(cal_factor) + "  ";
      disp_string[2] = "ADC Value=" + String(x);
      disp_string[3] = "PV=" + String(pressure_value, 2) + unit_label[unit_mode];
      break;
  }

  if (digitalRead(sw_up) == LOW) {
    delay(key_delay);
    if (set_value < max_limit) {
      std_value += 1;
      init_settings();
    }
    lcd.clear();
    display();
  }

  if (digitalRead(sw_dwn) == LOW) {
    delay(key_delay);
    if (std_value > min_limit) {
      std_value -= 1;
      init_settings();
    }
    lcd.clear();
    display();
  }

  if (digitalRead(sw_ent) == LOW) {
    delay(key_delay);
    run_mode = 1;
    disp_string[0] = "Inflate";
    disp_string[1] = " ";
    disp_string[2] = " ";
    disp_string[3] = " ";
    init_settings();
    lcd.clear();
    display();
  }

  // lcd.clear();
  // display();
}

void standby() {
  // set_mode = 5;
  digitalWrite(purge, HIGH);
  digitalWrite(feed, HIGH);
  lcd.clear();
  disp_string[1] = "Set PV:" + String(std_value) + unit_label[unit_mode];
  disp_string[2] = "Press Enter";
  disp_string[3] = "To Start Inflating";
  //display();
}
void inflate(float preset_pv) {
  pressure_value = read_sensor(unit_mode, cal_factor);
  if (pressure_value < (preset_pv + threshold)) {
    if (pressure_value < preset_pv) {
      disp_string[0] = "______Inflating_____";
      disp_string[1] = "SET PV=" + String(preset_pv, 2) + unit_label[unit_mode];
      disp_string[2] = "Tyre PV=" + String(pressure_value, 2) + unit_label[unit_mode];
      disp_string[3] = "Press SET To Stop   ";
      digitalWrite(purge, HIGH);
      digitalWrite(feed, LOW);
      display();
    } else {
      disp_string[0] = "Tyre Inflator";
      disp_string[1] = "Inflation Competed  ";
      digitalWrite(purge, HIGH);
      digitalWrite(feed, HIGH);
      lcd.clear();
      display();
      delay(2000);
      run_mode = 0;
    }
  }
  if (pressure_value > preset_pv) {
    disp_string[0] = "________Purging_____";
    disp_string[1] = "SET PV=" + String(preset_pv, 2) + unit_label[unit_mode];
    disp_string[2] = "Tyre PV=" + String(pressure_value, 2) + unit_label[unit_mode];
    disp_string[3] = "Press SET To Stop   ";
    digitalWrite(purge, LOW);
    digitalWrite(feed, HIGH);
    display();
  } else {
    disp_string[0] = "Tyre Inflator";
    disp_string[1] = "Inflation Competed  ";
    digitalWrite(purge, HIGH);
    digitalWrite(feed, HIGH);
    lcd.clear();
    display();
    delay(2000);
    run_mode = 0;
  }
}

void display() {
  for (int i = 0; i < 4; i++) {
    lcd.setCursor(0, i);
    delay(1);
    lcd.print(disp_string[i]);
    //Serial.println("L" + String(i) + ": " + disp_string[i]);
  }
  //delay(1000);
}

void save_settings(int address, int value) {
  EEPROM.write(address, value);
  EEPROM.update(address, value);
}

int load_settings(int address) {
  int x;
  x = EEPROM.read(address);
  return x;
}

void init_settings() {
  cal_factor = float(load_settings(2));
  if (cal_factor > 50) {
    save_settings(2, 1);
  }
  delay(1);
  unit_mode = load_settings(3);
  if (unit_mode > 3) {
    unit_mode = 1;
    save_settings(3, 1);
  }
  delay(1);
  std_value = load_settings(10 + unit_mode);
  switch (unit_mode) {
    case 0:  //BAR
      //scale_span = 16;
      if (std_value > 6) {
        std_value = 5;
        save_settings((unit_mode + 10), std_value);
      }
      break;
    case 1:  //Kg/cm2
      // scale_span = 16.316;
      if (std_value > 6) {
        std_value = 5;
        save_settings((unit_mode + 10), std_value);
      }
      break;
    case 2:  //PSI
      //scale_span = 232.06038;
      if (std_value > 35) {
        std_value = 35;
        save_settings((unit_mode + 10), std_value);
        break;
      }
  }
}

float read_sensor(int rmode, float calval) {
  float min_val = 100 + calval;
  float max_val = 921 + calval;
  float scale_span = 16.90;
  switch (rmode) {
    case 0:  //BAR
      scale_span = 16;
      break;
    case 1:  //Kg/cm2
      scale_span = 16.316;
      break;
    case 2:  //PSI
      scale_span = 232.06038;
      break;
  }
  float pv = analogRead(sensor_pin);
  pv = ((pv - min_val) * scale_span) / (max_val - min_val);
  return pv;
}