#include<LiquidCrystal.h>

LiquidCrystal lcd (2, 3, 4, 5, 6, 7);
#define ldr 8
int val;
int val2;
String duration;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(ldr, INPUT_PULLUP);
  lcd.begin(16,2);
  lcd.clear();
  lcd.print("LiFi Project");
  delay(3000);
  lcd.clear();
  lcd.print("Send any message");
  delay(3000);
  lcd.clear();
}
String Word="";
int y=0;
void loop() {
   lcd.clear();
   String binary=form_binary();
   int decimal = binary_to_decimal(binary);
   char character = (char)decimal;

   lcd.print(character);
   Word= Word+character;
   if (character==(char)binary_to_decimal("00000000"))
    { Serial.println(Word);
      Word="";

    lcd.clear();
    lcd.print("send any msg");
    delay(3000);
    }
    }

String form_binary()
{  
  String binary;
  for(int i=0 ;i<8;i=i+1){
     binary=binary+digitalRead(ldr);
     delay(500);}
  return  binary;
}

int binary_to_decimal(String binary) {
  int decimal = 0;
  int length = binary.length();
  for (int i = 0;i<length; i++) {
    if (binary[length - i - 1] == '1') {
      decimal += pow(2, i);
    }
  }
  
  return decimal;
}