#include /* Serial Event example When new serial data arrives, this sketch adds it to a String. When a newline is received, the loop prints the string and clears it. A good test for this is to try it with a GPS receiver that sends out NMEA 0183 sentences. NOTE: The serialEvent() feature is not available on the Leonardo, Micro, or other ATmega32U4 based boards. created 9 May 2011 by Tom Igoe This example code is in the public domain. http://www.arduino.cc/en/Tutorial/SerialEvent */ String inputString = ""; // a String to hold incoming data bool stringComplete = false; // whether the string is complete const int ledPin = 13;// the number of the LED pin void setup() { // initialize serial: Serial.begin(9600); // reserve 200 bytes for the inputString: inputString.reserve(200); // set the digital pin as output: pinMode(ledPin, OUTPUT); } void loop() { // print the string when a newline arrives: if (stringComplete) { Serial.println(inputString); if (inputString == "A\r\n") { //turn on LED digitalWrite(ledPin, HIGH); delay(1000); digitalWrite(ledPin, LOW); delay(1000); digitalWrite(ledPin, HIGH); delay(1000); digitalWrite(ledPin, LOW); delay(1000); Serial.print("B"); } else { digitalWrite(ledPin, HIGH); delay(5000); digitalWrite(ledPin, LOW); // delay(1000); } // clear the string: inputString = ""; stringComplete = false; } } /* SerialEvent occurs whenever a new data comes in the hardware serial RX. This routine is run between each time loop() runs, so using delay inside loop can delay response. Multiple bytes of data may be available. */ void serialEvent() { while (Serial.available()) { // get the new byte: char inChar = (char)Serial.read(); // add it to the inputString: inputString += inChar; // if the incoming character is a newline, set a flag so the main loop can // do something about it: if (inChar == '\n') { stringComplete = true; } } }