#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,20,4);

#include <DHT.h>
#define DHTPIN 9  
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

#define Serial Serial1

// display pinout
#define pinSDA 20
#define pinSCL 21

// sensor pinout
#define soil_pin 27
#define ph_pin 26
#define float_pin 14

// Outputs pinout
#define pump_pin 18
#define led_pin 13

// variables
float tempHigh = 30.0;
float drought = 50.0;
int moistureLow = 40;
float phLow = 6.5;
float phHigh = 8.4;
bool hasWater = false;

void setup() {
  Serial.begin(115200);
  analogReadResolution(12);
  
  Wire.setSDA(pinSDA);
  Wire.setSCL(pinSCL);
  Wire.begin();

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

  pinMode(soil_pin, INPUT);
  pinMode(ph_pin, INPUT);
  pinMode(float_pin, INPUT_PULLUP);

  pinMode(pump_pin, OUTPUT);
  pinMode(led_pin, OUTPUT);
  
  dht.begin();

  lcd.setCursor(6, 0);
  lcd.print("Automatic");
  delay(500);
  lcd.setCursor(5, 1);
  lcd.print("Irrigation");
  delay(500);
  lcd.setCursor(7, 2);
  lcd.print("System");
  delay(2000);
  lcd.clear();
}

void loop() {
  delay(1000);
  float temperature = dht.readTemperature();
  //Serial.print("Temperature : ");
  //Serial.print(temperature); 
  //Serial.println("°C");

  int moisture = map(analogRead(soil_pin),1680,3620,0,100);
  //Serial.print("Moisture : ");
  //Serial.print(moisture);
  //Serial.println("%");
  
  float phVal = ((float) analogRead(ph_pin) / 4095.0) * 14;
  //Serial.print("PH : ");
  //Serial.println(phVal);
  
  lcd.setCursor(0, 0);
  lcd.print("                    ");
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temperature,1);
  lcd.print((char) 223);
  lcd.print("C");
  lcd.print(" ");
  lcd.print("pH:");
  lcd.print(phVal,1);
  lcd.print(" ");
  lcd.print(moisture);
  lcd.print("%");

  if(digitalRead(float_pin) == HIGH){
    hasWater = true;
    lcd.setCursor(0, 1);
    lcd.print("Water Tank full    ");
  }
  else{
    hasWater = false; 
    lcd.setCursor(0, 1);
    lcd.print("Refill Water       ");
  }

  // when temperature exceeds 30C turn on the pump
  if(temperature > tempHigh && hasWater){
    digitalWrite(pump_pin,1);
    lcd.setCursor(0, 3);
    lcd.print("Pump Running       ");
  }
  
  // when temperature exceeds 30C turn on the red LED
  if(temperature > drought){
    digitalWrite(led_pin,1);
  }
  else{
    digitalWrite(led_pin,0);
  }

  // when soil moisture is below 40% turn on the pump
  if(moisture < moistureLow && hasWater){
    digitalWrite(pump_pin,1);
    lcd.setCursor(0, 3);
    lcd.print("Pump Running       ");
  }

  if(phVal < phLow || phVal > phHigh){
    lcd.setCursor(0, 2);
    lcd.print("poor pH level      ");
  }
  else{
    lcd.setCursor(0, 2);
    lcd.print("pH level good      ");
  }

  // pump turns off when temperature and moisture are within the range
  if((temperature < tempHigh) && (moisture > moistureLow)){
    digitalWrite(pump_pin,0);
    lcd.setCursor(0, 3);
    lcd.print("Pump Off           ");
  }
}