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Arduino/build/shared/examples/02.Digital/BlinkWithoutDelay/BlinkWithoutDelay.ino
Cristian Maglie a0727ac862 Merge branch 'master' into ide-1.5.x
Conflicts:
	build/shared/examples/02.Digital/BlinkWithoutDelay/BlinkWithoutDelay.ino
	build/shared/examples/09.USB/Keyboard/KeyboardMessage/KeyboardMessage.ino
	libraries/LiquidCrystal/examples/CustomCharacter/CustomCharacter.ino
	libraries/SD/examples/listfiles/listfiles.ino
2013-11-12 09:45:56 +01:00

68 lines
1.9 KiB
C++

/* Blink without Delay
Turns on and off a light emitting diode(LED) connected to a digital
pin, without using the delay() function. This means that other code
can run at the same time without being interrupted by the LED code.
The circuit:
* LED attached from pin 13 to ground.
* Note: on most Arduinos, there is already an LED on the board
that's attached to pin 13, so no hardware is needed for this example.
created 2005
by David A. Mellis
modified 8 Feb 2010
by Paul Stoffregen
modified 11 Nov 2013
by Scott Fitzgerald
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
*/
// constants won't change. Used here to set a pin number :
const int ledPin = 13; // the number of the LED pin
// Variables will change :
int ledState = LOW; // ledState used to set the LED
// Generally, you shuould use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0; // will store last time LED was updated
// constants won't change :
const long interval = 1000; // interval at which to blink (milliseconds)
void setup() {
// set the digital pin as output:
pinMode(ledPin, OUTPUT);
}
void loop()
{
// here is where you'd put code that needs to be running all the time.
// 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);
}
}