学习0基础ARDUINO电子设计实战指南第2个实验遇到问题

第二个实验是改变管脚控制发光二极管，我成功的改变了管脚，但是我再改回去以后发现13管脚的发光二极管和第7管脚的发光二极管居然同时闪亮，这个怎么回事呢？

代码贴上来看看。

这个是发光二极管插在13管脚闪亮的程序

/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
 
  This example code is in the public domain.
 */
 
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 13;

// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second
}
第七管脚插入发光二极管闪亮程序
/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
 
  This example code is in the public domain.
 */
 
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 7;

// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second
}
复制代码

代码看上去没问题。 烧了第二段程序，13号led 还是会亮？ 这就有点奇葩了。

是呀很奇怪啊

leozcr 发表于 2013-12-6 08:42
这个是发光二极管插在13管脚闪亮的程序

其实如果你不配置13号引脚的工作状态的话，mcu引脚的状态在我理解当中是浮动的。有的时候确实也会受到其他引脚工作状态的印象。

比如说，当你把模拟传感器接在A0，你读取A0的数据，在用指令读取A1模拟口1的数值，你会发现，模拟口1没有接设备，但是其读数会随着接有传感器模拟口0的读数变化。

可以尝试定义13号引脚的工作状态，并且初始化，看看还是否存在同样的现象。

/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.

  This example code is in the public domain.
*/

// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 7;

// the setup routine runs once when you press reset:
void setup() {               
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
  pinMode(13, OUTPUT);
  digitalWrite(13,LOW);
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second
}