//CONFIGURATION OF CIRCUIT

//SD Card Module:
//DO to Digital Pin 12
//GND to GND
//SCK to Digital Pin 13
//VCC to 5V Pin
//DI to Digital Pin 11
//CS to Digital Pin 10

//Temperature Sensor:
//VCC to 5V Pin
//GND to GND
//DQ to Digital Pin 8

//Moisture Sensor:
//VCC to 5V Pin
//GND to GND
//Analog Output to A0 Pin

//LCD 20x4 i2c:
//GND to GND
//VCC to 5V Pin
//SDA to A4 Pin
//SCL to A5 Pin

//Button:
//GND to GND
//Terminal 2 to Digital Pin 5

//Motor:
//GND to GND
//VCC to Digital Pin 9

//File Indicator LED:
//GND to GND
//VCC to Digital Pin 4

//NPK Sensor
//Cathode(Brown wire) to 9v/12v Power supply
//GND(Black wire) to power supply and GND Pin of MAX485 Modbus Module
//485B(Blue wire) to B Pin of MAX485 Modbus Module
//485A(Yellow wire) to A Pin of MAX485 Modbus Module

//MAX485 Modbus Module
//GND to GND
//VCC to 5V Pin
//DI to Digital Pin 3
//RO to Digital Pin 2
//DE to Digital Pin 6
//RE to Digital Pin 1

#include <SD.h>
#include <SPI.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>
#include <Wire.h>

File tempFile;
File moistFile;
File NPKFile;

#define ONE_WIRE_BUS 8
#define motorPin 9
#define vccMoist 7

#define AOUT_PIN A0

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

#define RE 1
#define DE 6

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

int temp;
const int pinCS = 10;
bool motorState = false;
String motorOnorOff = "OFF";
bool wetState;

//Button (Press this button to switch between the NPK sensor and other
//sensor values to be displayed in the LCD)
int button = 5;
int status = false;

bool lcdClearStatus = false;

const byte nitro[] = {0x01,0x03, 0x00, 0x1e, 0x00, 0x01, 0xe4, 0x0c};
const byte phos[] = {0x01,0x03, 0x00, 0x1f, 0x00, 0x01, 0xb5, 0xcc};
const byte pota[] = {0x01,0x03, 0x00, 0x20, 0x00, 0x01, 0x85, 0xc0};

byte values[11];
SoftwareSerial mod(2,3);

void setup() {
  Serial.begin(9600);
  sensors.begin();
  mod.begin(9600);

  pinMode (pinCS, OUTPUT);
  pinMode (4, OUTPUT);
  pinMode (motorPin, OUTPUT);
  pinMode (vccMoist, OUTPUT);

  pinMode(RE, OUTPUT);
  pinMode(DE, OUTPUT);

  pinMode (button, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();

  if (SD.begin()){
    Serial.println("SD Card is ready to use");
    Serial.println("");
  } else{
    Serial.println("SD Card Initialization Failed");
    return;
  }
}

void loop() {
  sensors.requestTemperatures();

  int temp = sensors.getTempCByIndex(0);

  int value = analogRead(AOUT_PIN);
  int percValue = value/1023.0*100; //Converts the moisture value to percentage

  tempFile = SD.open("temp.txt", FILE_WRITE);
  moistFile = SD.open("moist.txt", FILE_WRITE);
  NPKFile = SD.open("NPK.txt", FILE_WRITE);

  //NPK SENSOR
  byte val1,val2,val3;
  val1 = nitrogen();
  delay(100);
  val2 = phosphorous();
  delay(100);
  val3 = potassium();
  delay(100);

  
  if(digitalRead(button) == false){
    status = !status;
    lcd.clear();
    
    //NPK Values print to lcd
    lcd.setCursor(5, 0);
    lcd.println("NPK Sensor");

    lcd.setCursor(0, 1);
    lcd.print("N: ");
    lcd.print(val1);
    lcd.print(" mg/kg");
 
    lcd.setCursor(0, 2);
    lcd.print("P: ");
    lcd.print(val2);
    lcd.print(" mg/kg");
 
    lcd.setCursor(0, 3);
    lcd.print("K: ");
    lcd.print(val3);
    lcd.print(" mg/kg");

  } else {
    lcd.clear();
    lcd.setCursor(6, 0);
    lcd.println("SENSORS");

    //Temperature value print to lcd
    lcd.setCursor(0, 1);
    lcd.print("Temperature: ");
    lcd.println((String)temp+ " C");
    lcd.setCursor(0, 2);
    lcd.print("Motor ");
    lcd.println(motorOnorOff);

    //Moisture value print to lcd
    lcd.setCursor(0, 3);
    lcd.print("Moisture lvl: ");
    lcd.println((String)percValue+ " %");
  }

    //WRITE TEMPERATURE DATA TO SD CARD
    if(tempFile){
      tempFile.print(temp);
      tempFile.close();
      digitalWrite(4, HIGH); //This line is just to check if the txt file is created
    } else {
      Serial.println("Error Opening file");
    }

    //WRITE MOISTURE DATA TO SD CARD
    if(moistFile){
      moistFile.print(percValue);
      moistFile.close();
      digitalWrite(4, HIGH); //This line is just to check if the txt file is created
    } else {
      Serial.println("Error Opening file");
    }

    //WRITE NPK SENSOR DATA TO SD CARD
    if(NPKFile){
      NPKFile.println("N: " +val1);
      NPKFile.println("P: " +val2);
      NPKFile.println("K: " +val3);
      NPKFile.println("");
      NPKFile.close();
      digitalWrite(4, HIGH); //This line is just to check if the txt file is created
    } else {
      Serial.println("Error Opening file");
    }

    //Set motor On or Off based on temperature
    while(temp >= 90 && !motorState){
      digitalWrite(motorPin, HIGH);
      Serial.println("Motor ON");
      motorState = true;
      motorOnorOff = "ON";
    }
    while(temp <90 && motorState == true){
      digitalWrite(motorPin, LOW);
      Serial.println("Motor OFF");
      motorState = false;
      motorOnorOff = "OFF";
    }
  
    Serial.print("Moisture Level: ");
    Serial.print(value);
    Serial.println("");

    Serial.print("Celsius Temperature: ");
    Serial.println(sensors.getTempCByIndex(0));
    Serial.println("");

  delay(2000);
}

byte nitrogen(){
  digitalWrite(DE,HIGH);
  digitalWrite(RE,HIGH);
  delay(10);
  if(mod.write(nitro,sizeof(nitro))==8){
    digitalWrite(DE,LOW);
    digitalWrite(RE,LOW);
    for(byte i=0;i<7;i++){
    //Serial.print(mod.read(),HEX);
    values[i] = mod.read();
    Serial.print(values[i],HEX);
    }
    Serial.println();
  }
  return values[4];
}
 
byte phosphorous(){
  digitalWrite(DE,HIGH);
  digitalWrite(RE,HIGH);
  delay(10);
  if(mod.write(phos,sizeof(phos))==8){
    digitalWrite(DE,LOW);
    digitalWrite(RE,LOW);
    for(byte i=0;i<7;i++){
    //Serial.print(mod.read(),HEX);
    values[i] = mod.read();
    Serial.print(values[i],HEX);
    }
    Serial.println();
  }
  return values[4];
}
 
byte potassium(){
  digitalWrite(DE,HIGH);
  digitalWrite(RE,HIGH);
  delay(10);
  if(mod.write(pota,sizeof(pota))==8){
    digitalWrite(DE,LOW);
    digitalWrite(RE,LOW);
    for(byte i=0;i<7;i++){
    //Serial.print(mod.read(),HEX);
    values[i] = mod.read();
    Serial.print(values[i],HEX);
    }
    Serial.println();
  }
  return values[4];
}