Blink an led once without using a delay

Projects Programming
1

I have a nano watching sensors. when a sensor see something it toggles an led but that confuses people. I would like to be able to have the led turn on for 1/2 second then off but I can's use a delay because I need to be watching for more inputs from the sensors. I'd like if it sees an input and then 1/4 second later sees another one it just stays on 1/2 second from the last input.
The sensors are IR sensors and I'm using the code from Arduino Tutorials | tronixstuff.com so timer 2 is already used.
Is there a way I can set up another timer so that I can set it and it will turn on a pin for 1/2 second then turn it off and then do nothing until I trigger it again?
Thanks

2

You dont have to use a timer, use millis()

bool startBlink = false;
bool ledOn = false;
unsigned long blinkStarted;

void loop() {

  startBlink = true;    // this triggers the blink


  if (startBlink) {
    startBlink = false;
    blinkStarted = millis();
    ledOn = true;
    digitalWrite(13, HIGH);
  }
  if (ledOn && ((millis() - blinkStarted) >= 500)) {
    ledOn = false;
    digitalWrite(13, HIGH);
  }
}
3

looks like exactly what I wanted, thanks