#include <DigiCDC.h>
int incomingByte[] = {0x00,0x00,0x00};
int msg[] = {255,1};                        // FF=255 Header, 01 channel
 
void setup() {
  SerialUSB.begin();                        // Opens usb-serial port
  pinMode(1,OUTPUT);                        // Pin2 is used for onboard LED feedback
  digitalWrite(1,LOW);                      // Pin off as standard
 
}
 
void loop() {
  int msgflag = 1;
  if (SerialUSB.available() > 0) {
    // read the incoming byte:
    incomingByte[0] = SerialUSB.read();      // Read Bytes
    incomingByte[1] = SerialUSB.read();
    incomingByte[2] = SerialUSB.read();
 
    for (int i = 0;  i < 2; i++) {
      if ((incomingByte[i] == msg[i]) && msgflag == 1) {
        msgflag = 1;                         // Validate Header and channel
      }
      else {
        msgflag = 0;
      }
    }
    if (incomingByte[2] == 1) {            
          SerialUSB.print(0x06, HEX);     // ACKnowledge 
          digitalWrite(1,HIGH);           // Pin2 and onboard LED ON
 
      }
      else if (incomingByte[2] == 0) {
         SerialUSB.print(0x06, HEX);     // ACKnowledge 
          digitalWrite(1,LOW);            // Pin2 and onboardLED OFF
      }
    }
    }