#include<SoftwareSerial.h>
int led = 7;// declaring the LED pin
char ON = '1';// declaring that  ONturnon is the char the will be recived.
SoftwareSerial myserial(0, 1);

void setup() {
  myserial.begin(9600);

  pinMode(led, OUTPUT);
}

void loop()
{
  char chr = myserial.read();// chr will be equal to which the derial will read

  if (chr ==  ON) {// if the chr have the same value of ON, the LED will be ON.
    digitalWrite(led, HIGH);
    delay(100);
  }
  else {
    digitalWrite(led, LOW);
  }

}