/*This project is done to monitor the tank water level and to control the state of motor 
based on the level.

A arduino board is used to control the automation. A ultrasonic sensor is used to 
measure the distance. A rely module to control the current flow and Finally a lcd display 
to show the water level and the pump state

Here a led is used to represent the motor since it cannot show in the simulation.

Water level is measured based on the distance between the sensor and water.
Means if the distance is more water level is less and vice versa since the sensor will be 
fixed in the top side the tank.*/

//including the required libraries
#include <EEPROM.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(2,3,4,5,6,7);   // initialising the lcd 

//Declaring the required variables
long duration, inches;
int set_val,percentage;
bool state,pump;

//setting up the basic requirements.
void setup() {
  
  lcd.begin(20, 4);//initialising the lcd
  lcd.print("--< LEVEL SENSOR >--");
  lcd.setCursor(0, 1); 
  lcd.print("LIQUID LEVEL:");
  lcd.setCursor(0, 2); 
  lcd.print("VOLUME:");
  lcd.setCursor(2, 3); 
  lcd.print("PUMP STATUS:");
  
  //initialising the pinmodes
  pinMode(8, OUTPUT);
  pinMode(9, INPUT);
  pinMode(12, OUTPUT);
  
   set_val=EEPROM.read(0); //reading the values
   if(set_val>150)set_val=150;
}


void loop() {
  
   //trigger
   digitalWrite(3, LOW);
   delayMicroseconds(2);
   digitalWrite(8, HIGH);
   delayMicroseconds(10);
   digitalWrite(8, LOW);
   duration = pulseIn(9, HIGH);
   inches = microsecondsToInches(duration);
   
   percentage=(set_val-inches)*100/set_val;//calculating the water level percentage
   
   //displaying the water level in percentage
   lcd.setCursor(15, 1); 
   if(percentage<0)percentage=0;
   lcd.print(percentage);
   lcd.print("%   ");
   lcd.setCursor(17, 2);
   lcd.print("Ltr");
    
    // swtiching motor state based the read value
   if(percentage<30)pump=1;
   if(percentage>80)pump=0;
   digitalWrite(12,!pump);

    //displaying the pump/motor state 
   lcd.setCursor(15, 3);
   if(pump==1)lcd.print("ON ");
   else if(pump==0) lcd.print("OFF");
   
}
long microsecondsToInches(long microseconds) {
   return microseconds / 74 / 2;
}