Continuous Blinking Led

Projects Programming
1

Hey guys

I am wondering if i can have a continuous blinking led while my main sketch is running.

Thanks

Ian

2

Yes you can since you program it.

What is your project?

3

See blink without delay and the look up Finite Sate Machines (FSM) in the playground/examples.

Mark

4

Yes, but probably not in the way you are thinking. That is, the LED cannot just blink by itself. However, you also don't need to put a delay in your main loop (for the blinking LED)

Try something like this:

int led = 13;
bool ledOn = false;
int blinkRate = 500; // blink every 1/2 second
unsigned long blinkTimer;

void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
  blinkTimer = millis();
}

void loop() {

// include this call anywhere in your main loop
  BlinkMyLed();
}

void BlinkMyLed() {
  if (millis() + blinkTimer > blinkRate) {
    blinkTimer = millis();
    digitalWrite(led, ledOn);
    ledOn = !ledOn;
  }
}
5

ianscott-arduino:
Hey guys

I am wondering if i can have a continuous blinking led while my main sketch is running.

an

if (millis() + blinkTimer > blinkRate) {

you will want to stay away from addition with unsigned long math, you will have rollover/overflow problems...

a better approach would be subtraction...

int ledPin = 13;

void setup()
{
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
}

void loop()
{
  blinkMyLed();
}

void blinkMyLed()
{
  static unsigned long lastBlinkTime = 0;
  if (millis() - lastBlinkTime >= 50UL)
  {
    digitalWrite(ledPin, !digitalRead(ledPin)); //toggles the led
    lastBlinkTime = millis();
  }
}