// Start By THe Name Of Allah
// Compatible with the Arduino IDE 1.0
// Library version:1.1
#include <LiquidCrystal_I2C.h>

#define PIN_TRIG 3
#define PIN_ECHO 2

// set the LCD address to 0x27 for a 20 chars and 4 line display
LiquidCrystal_I2C lcd(0x27,20,4);

//Declaring the required variables
bool state,pump; //Pump
float cm; // Measured length
float L = 220.0; //Lenght
float D = 124.2; // Dia
float A = 19.6; // Dish distance
float R; //Radius
float H; // Liquid hight
float Ltr; // Total Liters
float Percentage; // % Liquid hight

void setup()
{
	Serial.begin(115200);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

	// initialize the lcd
  lcd.init();	

  // Print a message to the LCD.
  lcd.backlight();
	lcd.setCursor(0,0);
  lcd.print("LEVEL SENSOR TM-V0.1");
	lcd.setCursor(0,1);
	lcd.print("DESIGND BY I_SHARIF");
	lcd.setCursor(0,2);
	lcd.print("TECHNICAL MINDS PAK");
	lcd.setCursor(0,3);
	lcd.print("+92 300/321 9408622");
	delay(3000);
	lcd.clear();
  pinMode(13, OUTPUT);
}

void loop()
{
	// Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

// Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  cm = (duration / 58.475);
	R = D/2;
	H = D + 2 - cm; 
   if(H<0)H=0;
	Ltr = (L * ((sq(R) * acos(((R) - H) / (R))) - (((R) - H) * sqrt(2 * (R) * H - sq(H)))) + PI * A * sq(H) * (1 - (H / (3 * (R))))) / 1000;
	Percentage = H * 100 / D;
    
	//displaying the liquid level & liters
	 lcd.setCursor(0,0);
	 lcd.print("TANK LEVEL:");
	 lcd.setCursor(12, 0); 
	 if(Percentage>90)lcd.print("TO HIGH");
	 else if(Percentage<20)lcd.print("TO LOW");
	 else if(Percentage<25)lcd.print("LOW");
	 else if(Percentage>25 && Percentage<85)lcd.print("NORMAL");
	 else if(Percentage>85)lcd.print("HIGH");
	 lcd.setCursor(0,1);
	 lcd.print("LIQUID HIGHT:");
	 lcd.setCursor(13,1);
	 lcd.print(H, 1);
	 lcd.print("cm");
	 lcd.setCursor(0, 2);
	 lcd.print("LITERS:");
	 lcd.setCursor(10, 2);
	 lcd.print(Ltr, 1);
   lcd.print("Ltr");

	//displaying the liquid level in percentage
	 lcd.setCursor(11, 3);
	 lcd.print("LH:");
   lcd.setCursor(14, 3); 
   if(Percentage<0)Percentage=0;
   lcd.print(Percentage, 1);
   lcd.print("%");

	// swtiching motor state based the read value
   if(Percentage<30)pump=1;
   if(Percentage>80)pump=0;
   digitalWrite(13,pump);

  //displaying the pump/motor state 
	 lcd.setCursor(0, 3); 
   lcd.print("PUMP:");
   lcd.setCursor(5, 3);
   if(pump==1)lcd.print("ON ");
   else if(pump==0) lcd.print("OFF");
	 delay(1000);
	 lcd.clear();
}