如何在開始前延遲2秒才實現

andywwf

請問要如何在開始閃燈前, 先延遲2秒才觸發閃燈?
PS. 只在開始時發生一次2秒延遲

1. // constants won't change. Used here to set a pin number:
   
2. const int ledPin =  LED_BUILTIN;// the number of the LED pin
   
3. 
   
4. // Variables will change:
   
5. int ledState = LOW;             // ledState used to set the LED
   
6. 
   
7. // Generally, you should use "unsigned long" for variables that hold time
   
8. // The value will quickly become too large for an int to store
   
9. unsigned long previousMillis = 0;        // will store last time LED was updated
   
10. 
    
11. // constants won't change:
    
12. const long interval = 1000;           // interval at which to blink (milliseconds)
    
13. 
    
14. void setup() {
    
15.   // set the digital pin as output:
    
16.   pinMode(ledPin, OUTPUT);
    
17. }
    
18. 
    
19. void loop() {
    
20.   // here is where you'd put code that needs to be running all the time.
    
21. 
    
22.   // check to see if it's time to blink the LED; that is, if the difference
    
23.   // between the current time and last time you blinked the LED is bigger than
    
24.   // the interval at which you want to blink the LED.
    
25.   unsigned long currentMillis = millis();
    
26. 
    
27.   if (currentMillis - previousMillis >= interval) {
    
28.     // save the last time you blinked the LED
    
29.     previousMillis = currentMillis;
    
30. 
    
31.     // if the LED is off turn it on and vice-versa:
    
32.     if (ledState == LOW) {
    
33.       ledState = HIGH;
    
34.     } else {
    
35.       ledState = LOW;
    
36.     }
    
37. 
    
38.     // set the LED with the ledState of the variable:
    
39.     digitalWrite(ledPin, ledState);
    
40.   }
    
41. }

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mounsea1

放在setup里一段，或者设置一个标志位，用个if判断是否是第一次执行

andywwf

mounsea1 发表于 2022-1-14 10:27
放在setup里一段，或者设置一个标志位，用个if判断是否是第一次执行

不好意思, 我是新手.
可否說明詳細一些?

shouzama

andywwf 发表于 2022-1-14 21:17
不好意思, 我是新手.
可否說明詳細一些?

在 setup() 裏面放一條延遲 2 秒的指令
delay(2000);
就只有在開機時才會延遲