#include <SoftwareSerial.h>
  SoftwareSerial mySerial(1, 0);

const int ledPin = 7;

void setup() {

CLKPR = (1 << CLKPCE);
CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);

mySerial.begin(9600); 

pinMode (ledPin, OUTPUT);

}

void loop() {
  if(mySerial.available()) {
    while(mySerial.available()){
      mySerial.read();
      digitalWrite(ledPin, HIGH);
      delay(50);
      digitalWrite(ledPin, LOW);
      delay(50);
   }
 }
}