#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
const int trigger = 32;
const int echo = 33;
const int pump = 25;

int levellow = 40;
int levelhigh = 10;
int pumpstate = LOW;
void setup(){
    lcd.init();
    lcd.backlight();
    lcd.clear();
    pinMode(trigger, OUTPUT);
    pinMode(echo, INPUT);
    pinMode(pump, OUTPUT);
}

void loop(){
    digitalWrite(trigger, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigger, LOW);
    
    long duration = pulseIn(echo, HIGH);
    float distance = (duration/2)/29.1;
    
    int waterlevel = map(distance * 100, levelhigh * 100, levellow * 100, 100, 0);
    waterlevel = constrain(waterlevel, 0, 100);
    
    lcd.setCursor(0,0);
    lcd.print("WATERLEVEL=");
    lcd.print(waterlevel);
    lcd.print("%");
    
    if(distance >= levellow){
    digitalWrite(pump, HIGH);
    lcd.setCursor(0,1);
    lcd.print("WATERPUMP=ON ");
}
    else if(distance <= levelhigh){
    digitalWrite(pump, LOW);
    lcd.setCursor(0,1);
    lcd.print("WATERPUMP=OFF");
    
    }
}