void setup() {
  //Turn on serial
  Serial.begin(9600);
  //Set control pins as outputs
  pinMode(2, OUTPUT);   
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
}

void loop() {
  //Wait for control data to come in
  if (Serial.available() > 0){
    char character;
    while(Serial.available()) {
      character = Serial.read();
      //Switch corresponding output. Change the characters here to listen for something else.
      if(character == '1'){
        digitalWrite(2, !digitalRead(2));
      }
      if(character == '2'){
        digitalWrite(3, !digitalRead(3));
      }
      if(character == '3'){
        digitalWrite(4, !digitalRead(4));
      }
      if(character == '4'){
        digitalWrite(5, !digitalRead(5));
      }
      if(character == '5'){
        digitalWrite(6, !digitalRead(6));
      }
      if(character == '6'){
        digitalWrite(7, !digitalRead(7));
      }
    }
  }
}