#include <SoftwareSerial.h>
 #define LED 5
 void setup()
 {
  pinMode(LED, OUTPUT);
  Serial.begin(9600);
  }
 void loop()
 {
   if (Serial.available())
   {
  String value=Serial.readString();
    Serial.println(value);
  if(value=="ON"|| value=="on")
  {
    digitalWrite(LED, HIGH);

  }
  else if(value=="OFF"|| value=="off")
  {
    digitalWrite(LED, LOW);
  }
  delay(10);
 }
 }