#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);
float calibration_value = 21.34;
int phval = 0; 
unsigned long int avgval; 
int buffer_arr[10],temp;

void setup() {
  Serial.begin(9600);
  lcd.init(); 
  lcd.begin(16, 2);
  lcd.backlight();
  lcd.setCursor(0, 0);
  
}

void loop() {
 for(int i=0;i<10;i++) 
 { 
 buffer_arr[i]=analogRead(0);
 delay(30);
 }
 for(int i=0;i<9;i++)
 {
 for(int j=i+1;j<10;j++)
 {
 if(buffer_arr[i]>buffer_arr[j])
 {
 temp=buffer_arr[i];
 buffer_arr[i]=buffer_arr[j];
 buffer_arr[j]=temp;
 }
 }
 }
 avgval=0;
 for(int i=2;i<8;i++)
 avgval+=buffer_arr[i];
 float volt=(float)avgval*5.0/4095/6;
 float ph_act = -5.70 * volt + calibration_value;
 lcd.setCursor(0, 0);
 lcd.print("PH :");
 lcd.setCursor(9, 0);
 lcd.print(ph_act);
 lcd.setCursor(0,1);
 lcd.print("DO :");
 lcd.setCursor(9,1);
 float DO=(analogRead(2)/204.5);
 lcd.print(DO);
 delay(1000);

}