Sketch that responds to certain commands, how is it done?

Question

Alright I have a half complete Arduino sketch at the moment. Basically the sketch below will blink an LED on a kegboard-mini shield if a string of chars equals *{blink_Flow_A}*

Answer 1

Perhaps something like the 'blink without delay' example in the IDE. You check the time and decide to when and how to change the LED/Digital out.

// Variables will change:
int ledState = LOW;             // ledState used to set the LED
long previousMillis = 0;        // will store last time LED was updated

// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long interval = 1000;           // interval at which to blink (milliseconds)

void setup(){
    // Your stuff here
}


void loop()
{
 // Your stuff here.

 // check to see if it's time to blink the LED; that is, if the 
 // difference between the current time and last time you blinked 
 // the LED is bigger than the interval at which you want to 
 // blink the LED.
 unsigned long currentMillis = millis();

if(currentMillis - previousMillis > interval) {
  // save the last time you blinked the LED 
  previousMillis = currentMillis;   

  // if the LED is off turn it on and vice-versa:
  if (ledState == LOW)
    ledState = HIGH;
  else
    ledState = LOW;

  // set the LED with the ledState of the variable:
  digitalWrite(ledPin, ledState);
}
}