Watering system using Arduino and RTC module

//This source code belongs to the following tutorial video: https://youtu.be/Qb7H7ubF6DE
//If you used the code, please consider subscribing to my channel:https://www.youtube.com/channel/UCKp1MzuAceJnDqAvsZl_46g
//Thank you!

/*Automatic irrigation system
 * Arduino NANO
 * Relay module
 * RTC module
 * 16x2 LCD module
 * 12 V DC water pump (240L/h = 66,67 ml / sec)
 * ON-ON Swtich, resistor for debouncing
 *
 */

/*
You can buy the parts and help me by using the following links:
Arduino Nano with expansion board: https://www.banggood.com/custlink/vDGD9KnOHl
16x2 LCD (I2C): https://www.banggood.com/custlink/KmGGgtP2Lv
DS3231 RTC Module: https://www.banggood.com/custlink/GKDGNrNnmS
5V Relay for Arduino: https://www.banggood.com/custlink/DKmDQJn4sZ
2.1 mm DC jack (male-female): https://www.banggood.com/custlink/mmK3bJA4No
12V 2A Power Adapter: https://www.banggood.com/custlink/Gvmvnrbesb
Submersible Pump: https://www.banggood.com/custlink/vDmmH67p9C
ON-ON Switch: https://www.banggood.com/custlink/mKG3QcAnKB
*/

#include <Wire.h>
#include <RTClib.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
RTC_DS1307 RTC;

//--------------------------------
bool newData; //new data on serial
bool watering = false; //status if watering is allowed or not
bool wateredtoday = false;

int wateringhour = 9; // water at 9:00 o'clock in the morning (24h time format!)
float wateringlength = 6000; //10 sec default watering (pumping time)

const int relaypin = 2;
const int switchpin = 3;
int switchstate = 0;
char receivedCommand;

//--------------------------------


void setup()
{
  //------------------------------------------------------
  lcd.init();                      // initialize the lcd
  lcd.init();
  lcd.backlight();
  //------------------------------------------------------


  pinMode(relaypin, OUTPUT);
  pinMode(switchpin, INPUT);

  Serial.begin(9600);

  Wire.begin();

  RTC.begin();

  //Refreshing time
  //remove "!", compile, upload to refresh the time in the RTC module
  //the time will be set to the time of the compilation
  if (! RTC.isrunning())
  {
    Serial.println("RTC is NOT running!");
    // following line sets the RTC to the date & time this sketch was compiled
    RTC.adjust(DateTime(__DATE__, __TIME__));
  }

  Serial.println("Irrigation system.");

  //Fancy startup
  lcd.clear();
  lcd.setCursor(0,0); //Defining positon to write from first row,first column .
  lcd.print("Watering System");
  lcd.setCursor(0,1);
  lcd.print("Start in 5..."); //You can write 16 Characters per line .
  delay(1000); //wait 3 sec
  lcd.setCursor(0,1);
  lcd.print("Start in 4..."); //You can write 16 Characters per line .
  delay(1000); //wait 3 sec
  lcd.setCursor(0,1);
  lcd.print("Start in 3..."); //You can write 16 Characters per line .
  delay(1000); //wait 3 sec
  lcd.setCursor(0,1);
  lcd.print("Start in 2..."); //You can write 16 Characters per line .
  delay(1000); //wait 3 sec
  lcd.setCursor(0,1);
  lcd.print("Start in 1..."); //You can write 16 Characters per line .
  delay(1000); //wait 3 sec


}

void loop()
{

 printtime();
 checkSerial();
 checktime();
 switchcheck();
 executecommand();

}
//----------------------------------------------------------------------------------
void checkSerial()
{
  //First we check if there is data on the serial port, i.e. we sent a command
     if (Serial.available() > 0)
     {
        receivedCommand = Serial.read();
        newData = true;
     }

     //if there is a command, then we step inside and go through the possible commands
     if (newData == true) {

      if(receivedCommand == 'w') //w = watering
      {
        watering = true;        //change the boolean, so the watering will be ENABLED
      }

      if(receivedCommand == 's') //s = stop
      {
         watering = false;    //change the boolean, so the watering will be DISABLED
      }



    }
    else
    {}
    newData = false;

}
//----------------------------------------------------------------------------------
void executecommand() //execute the commands, i.e. checking which flag is en/dis-abled
{
  if(watering == true)
  {
    //start pump
    digitalWrite(relaypin, HIGH);


    //------------------------------------------------------
    //---print info on LCD
    lcd.clear();
    lcd.setCursor(0,0); //Defining positon to write from first row,first column .
    lcd.print("Watering");
    lcd.setCursor(0,1);
    lcd.print("Running"); //You can write 16 Characters per line .
    //---Run pump for some time (defined in the beginning of the code as a variable)
    delay(wateringlength);
    //---Shut down pump, set pin to LOW
    digitalWrite(relaypin, LOW);
    //---Clean screen
    lcd.clear();
    //---Disable watering
    watering = false;
    //--Change the value of the bool, so we'll know that the watering had happened
    wateredtoday = true;
  }
  else
  {
   //do not do anything
  }
  //---------------------------

}

//----------------------------------------------------------------------------------

void printtime()
{
    //it is just a basic RTC and LCD exercise: reading the date and time and printing it with some formatting
    DateTime now = RTC.now();
    //-----------------
    //--First line
    lcd.clear();
    lcd.setCursor(0,0); //Defining positon to write from first row,first column .
    lcd.print(now.year());
    lcd.setCursor(4,0);
    lcd.print(".");
    lcd.setCursor(5,0);
    lcd.print(now.month());
    lcd.setCursor(7,0);
    lcd.print(".");
    lcd.setCursor(8,0);
    lcd.print(now.day());
    lcd.setCursor(11,0);
    lcd.print("water");
    //-----------------
    //--Second line
    lcd.setCursor(0,1);
    lcd.print(now.hour()); //You can write 16 Characters per line .
    lcd.setCursor(2,1);
    lcd.print(":");
    lcd.setCursor(3,1);
    lcd.print(now.minute());
    lcd.setCursor(5,1);
    lcd.print(":");
    lcd.setCursor(6,1);
    lcd.print(now.second());
    lcd.setCursor(10,1);
    //if the watering had happened, then we print it on the screen.
    if(wateredtoday == true)
    {lcd.print("true");}
    else
    {lcd.print("false");}

    //----------------------------------------
    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    Serial.print(now.day(), DEC);
    Serial.print(' ');
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();
    delay(1000);
}
//----------------------------------------------------------------------------------

void checktime()
{
  //Here, we check the time, so we can see if the watering should be started
  DateTime now = RTC.now();

  //after the watering time occured, we switch the variable back to false so when the
  //time occurs again (i.e. it is 9:00 in the morning) the watering will be started again
  if(now.hour() == (wateringhour +1))
  {
    //Serial.println("Watered");
    wateredtoday = false;
  }

  //If it is time to water, and we haven't watered, we enable watering
  if(now.hour() == wateringhour && wateredtoday == false)
  {
    //Serial.println("Not watered");
    watering = true;
    wateredtoday = true;
  }

}

void switchcheck()
{
  //We check the switch which is used to manually run the pump
  //this does not change ANYTHING with the regular, scheduled pumping.

  //Serial.println("SwitchCheck");

  switchstate = digitalRead(switchpin); //read the pin

  if (switchstate == HIGH) {

  //Serial.println("switch is HIGH");
  //Serial.println(digitalRead(switchpin));

  digitalWrite(relaypin, HIGH);

  } else {

    digitalWrite(relaypin, LOW);
    //Serial.println("switch is LOW");
   // Serial.println(digitalRead(switchpin));

  }

}