Question

您好我是Arduino的新手并且我试图创建1秒延迟，但我不知道如何生成完成delay_ms功能的代码我试图解决这个问题，但似乎没有做得更好谢谢 void setup（） {

word millisecs;   
Serial.begin(9600); 
}   
void setup() asm volatile(
"          ldi r16,0x3F    ; r16 = 00111111\n"
"          out 4,r16       ; set pins 8-13 as outputs in DDRB\n"
::: "r16");
millisecs = 1000;            // 1s blink delay
Serial.begin(9600);
}
void loop() 
{
long starttime = millis();        // make a note of the start time

asm volatile(
// jump to "blink" - ie jump around the delay_ms subroutine
"            rjmp  blink%=        ; relative jump to 'blink' \n"
  "          ldi r16,0x3F    ; r16 = 00111111\n"
"          out 4,r16       ; set pins 8-13 as outputs in DDRB\n"
::: "r16");

 registers used:
 r31 - millisecond count (lo byte)
 r30 - millisecond count (hi byte)
 r17 - 100 microsecond count
 r16 - 1 microsecond count
Overall delay (ms) = r30:r31 * r17 * r16
---------------------------------------------------------------------*/
"delay_ms%=:    nop                 ; code to replace  nop  \n"
"delay_100us%=: nop                 ; code to replace  nop  \n"
"delay_1us%=:   nop                 ; code to replace nop  \n"
"               sbiw r30,1          ; decrement ms count (r31:r30)\n"
"               brne delay_ms%=     ; loop to delay_ms while > 0  \n"
"               ret                 ; return from subroutine      \n"

Answer 1

内置了这样做

http://arduino.cc/en/Reference/delay

你只需要给它延迟的ms数。所以一秒钟

delay(1000)

Answer 2

对于这么简单的事情，你的工作方式太难了。请参阅BlinkWithoutDelay（以下代码）。该代码也是安装Arduino IDE时安装的Arduino示例的一部分。那里有很多好的学习例子。（哦 - 代码对var long使用previousMillis。这是一个错误（imo）。最好使用unsigned long。）

你也可以选择使用Timer interrupts，但是对于一个简单的第二次延迟（特别是如果你没有太多经验），我会建议上面的方法并在代码中完成所有这些理解。

/* 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

 This example code is in the public domain.


 http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
 */

// constants won't change. Used here to
// set pin numbers:
const int ledPin =  13;      // the number of the LED pin

// Variables will change:
int ledState = LOW;             // ledState used to set the LED
long previousMillis = 0;        // will store last time LED was updated

// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
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);
  }
}

如何创建1秒延迟Arduino

2 个答案: