Arduino之数字处理：无延时LED闪烁

Arduino之数字处理：无延时LED闪烁

本示例演示了如何在不使用delay()来点亮LED。点亮LED，并记录下时间。然后，每次通过loop()时，检测是否已经超过设定的闪烁时间。如果是，则改变LED的打开或关断状态，并设定新的时间。通过这种方式，LED连续闪烁的同时示例执行不会错过任何一条指令。

所需硬件

1. Arduino或者Genuino开发板
2. Arduino IDE 1.8.9
3. LED
4. 220欧电阻

电路连接方式

原理图

Arduino IDE 1.8.9调试过程

贴入代码后执行验证/编译，然后插入开发板后执行上传

代码如下

// An highlighted block
/* 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 should 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);
  }
}

测试效果图

参考内容：https://www.yiboard.com/thread-579-1-1.html