int led_r = 6;
int led_g = 9;
int led_b = 11;
char rgb;                                       // Variable to store submitted command

void setup() {
  pinMode(15,OUTPUT);                           // Set SysOn PIN as output
  digitalWrite(15,HIGH);                        // Set SysOn HIGH to power PCB
  pinMode(led_r,OUTPUT);                        // Set LED pins as output
  pinMode(led_g,OUTPUT);
  pinMode(led_b,OUTPUT);
  digitalWrite(led_r, HIGH);                    // turn off LEDs on start up
  digitalWrite(led_g, HIGH);
  digitalWrite(led_b, HIGH);

  Serial.begin(9600);                           // initialize serial connection with 9600 baud
}
 void loop() {
   if (Serial.available()) { // check if data is available on the serial port
     rgb = Serial.read(); // read and store the data in the variable
   }
   if (rgb == '1') { 
     digitalWrite(led_r, LOW); // red LED on
   } else if (rgb == '2') {
      digitalWrite(led_g, LOW); // green LED on
   } else if (rgb == '3') {
      digitalWrite(led_b, LOW); // blue LED on
   } else if (rgb == '4') {
      digitalWrite(led_r, LOW); // all 3 LEDs on
      digitalWrite(led_g, LOW);
      digitalWrite(led_b, LOW); 
   } else if (rgb == '0') {     
     digitalWrite(led_r, HIGH); // turn all LEDs off
     digitalWrite(led_g, HIGH);
     digitalWrite(led_b, HIGH);
   }
   delay(10);
}