c++ - Arduino - 通过按钮停止循环

Question

所以我一直在试验 TinkerCad，等待我的 arduino 到来。目前我有一个 LED 灯循环，我想通过按一个按钮来启动和停止循环。

目前我可以通过按钮开始我的循环，但无法通过按下相同的按钮来停止循环。这和去抖有关系吗？

const int button = 10;
const int led1 = 8;
const int led2 = 4;
const int led3 = 3;
const int timedelay = 250;

boolean buttonstate = false;  

void setup()
  {

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(button, INPUT);
}

void loop() {

if(digitalRead(button)==HIGH)  // check if button is pushed
   buttonstate = !buttonstate;    //reverse buttonstate value

   if(buttonstate==true)
  {  
    digitalWrite(led1, HIGH);
    delay(timedelay); 
    digitalWrite(led1, LOW);
    delay(timedelay); 
    digitalWrite(led2, HIGH);
    delay(timedelay);
    digitalWrite(led2, LOW);
    delay(timedelay);
    digitalWrite(led3, HIGH);
    delay(timedelay);
    digitalWrite(led2, HIGH);
    delay(timedelay);
    digitalWrite(led1, HIGH); 
    delay(timedelay);
    digitalWrite(led3, LOW);
    delay(timedelay);
    digitalWrite(led2, LOW);
    delay(timedelay);
    digitalWrite(led1, LOW); 
    delay(timedelay);
    digitalWrite(led1, HIGH); }
   else {
        digitalWrite(led1, HIGH);
  }     
}

我的电路设置:



编辑:

我已经调整了我的代码，用毫秒替换了延迟并寻找按钮状态的变化。仍在寻找一种在循环结束时调整 interval_led1 以制作病态 LED 灯序列的方法。

const int led1 = 13;
const int led2 = 8;
const int led3 = 5;
const int button = 10;
int ledState_led1 = LOW;             // ledState used to set the LED
int ledState_led2 = LOW;
int ledState_led3 = LOW;


// 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_led1 = 0;        // will store last time LED was updated
unsigned long previousMillis_led2 = 0;
unsigned long previousMillis_led3 = 0;

long interval_led1 = 500;           // interval at which to blink (milliseconds)
long interval_led2 = 600;
long interval_led3 = 700;

boolean buttonstate = false;


void setup() {

pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(button, INPUT);

}





void loop() {
   // 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_led1 = millis();
  unsigned long currentMillis_led2 = millis();
  unsigned long currentMillis_led3 = millis();

  bool current_state = digitalRead(button);
  bool prev_buttonstate= false;

if(current_state==HIGH && current_state != prev_buttonstate)
{  
   buttonstate = !buttonstate;    //reverse buttonstate value
}
prev_buttonstate = current_state;



if(buttonstate==true)
    if (currentMillis_led1 - previousMillis_led1 >= interval_led1) {
    previousMillis_led1 = currentMillis_led1;
    if (ledState_led1 == LOW) {
      ledState_led1 = HIGH;
    } else {
      ledState_led1 = LOW;
    }
    digitalWrite(led1, ledState_led1);
    }

if(buttonstate==true)    
    if (currentMillis_led2 - previousMillis_led2 >= interval_led2) {
    previousMillis_led2 = currentMillis_led2;
    if (ledState_led2 == LOW) {
      ledState_led2 = HIGH;
    } else {
      ledState_led2 = LOW;
    }
    digitalWrite(led2, ledState_led2);
    }

if(buttonstate==true)
    if (currentMillis_led3 - previousMillis_led3 >= interval_led3) {
    previousMillis_led3 = currentMillis_led3;
    if (ledState_led3 == LOW) {
      ledState_led3 = HIGH;
    } else {
      ledState_led3 = LOW;
    }
    digitalWrite(led3, ledState_led3);
    }
}

Answer 1

在这里，您的两种情况在延迟方面非常不同:if(buttonstate==true) 执行时间很长，因为其中有多个 delay 指令，else 非常快，因为其中没有 delay。

当 buttonstate==True 并且您按下按钮时(正如 Delta_G 所说，delay() 阻止测试在大多数情况下发生，您应该使用 millis() 例如进行计时，但假设您很幸运并且通过了您的第一个 if 语句)，所以 buttonstate 将翻转为 false 。

由于您的 else 指令没有延迟，电路板将立即返回到您的初始 if ，不幸的是，它仍然是 true ，因为您的速度不够快，无法仅按此按钮几微秒。因此 buttonstate 将再次翻转，您的代码将落入您的 if(buttonstate==true) 中，这很长，允许您在重新评估 if(digitalRead(button)==HIGH) 之前及时释放按钮。

解决方案(除了@Delta_G 提出的计时问题和@TomServo 提出的硬件问题)是寻求按钮状态的变化。因此，您必须与它之前的值进行比较。您可以声明另一个 bool 值 boolean prev_buttonstate = false; 并且可以执行以下操作:

bool current_state = digitalRead(button);
if(current_state==HIGH && current_state != prev_buttonstate)
{  
   buttonstate = !buttonstate;    //reverse buttonstate value
}
prev_buttonstate = current_state;

希望能帮助到你!