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Arduino输入波动

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Arduino输入波动,arduino,Arduino,通过下面的代码，我得到了一个类似下面的日志。为什么呢 int analogPin = 5; int val = 0; void setup(void) { Serial.begin(9600); } void loop(void) { val = analogRead(analogPin); Serial.print("Analog reading = "); Serial.println(val); } 结果: Analog reading = 998 An

通过下面的代码，我得到了一个类似下面的日志。为什么呢

int analogPin = 5;
int val = 0;

void setup(void) {
   Serial.begin(9600);
}

void loop(void) {
   val = analogRead(analogPin);
   Serial.print("Analog reading = ");
   Serial.println(val);   
}

结果:

Analog reading = 998
Analog reading = 981
Analog reading = 511
Analog reading = 159
Analog reading = 24
Analog reading = 108
Analog reading = 439
Analog reading = 946
Analog reading = 1023
Analog reading = 420
Analog reading = 116
Analog reading = 25
Analog reading = 151
Analog reading = 542
Analog reading = 997
Analog reading = 982
Analog reading = 513
Analog reading = 161
Analog reading = 25
Analog reading = 107
Analog reading = 437
Analog reading = 945
Analog reading = 1023
Analog reading = 421
Analog reading = 117
Analog reading = 25
Analog reading = 150
Analog reading = 541
Analog reading = 997
Analog reading = 983
Analog reading = 515
Analog reading = 162
Analog reading = 25
Analog reading = 107
Analog reading = 437
Analog reading = 945
Analog reading = 1023
Analog reading = 422
Analog reading = 117
Analog reading = 25
Analog reading = 149
Analog reading = 540
Analog reading = 997
Analog reading = 983
Analog reading = 516
Analog reading = 162
Analog reading = 25
Analog reading = 107
Analog reading = 436
Analog reading = 945
Analog reading = 1023
Analog reading = 422
Analog reading = 117
Analog reading = 25
Analog reading = 150
Analog reading = 540
Analog reading = 998
Analog reading = 982
Analog reading = 516
Analog reading = 162
Analog reading = 25
Analog reading = 108
Analog reading = 437

结果只是噪音吗

一旦我插入电缆，我就会看到以下模式：

Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 72
Analog reading = 447
Analog reading = 1023
Analog reading = 1023
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 118
Analog reading = 849
Analog reading = 1023
Analog reading = 835
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 40
Analog reading = 401
Analog reading = 1023
Analog reading = 1023
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 0
Analog reading = 89
Analog reading = 475
Analog reading = 1023
Analog reading = 1023

那是我的心跳吗？？？不知道什么会对空管脚产生这样的影响。

是的，未连接的模拟管脚产生随机噪声是很正常的。从（我的）重点：

如果由

random（）

生成的值序列不同很重要，则在后续执行草图时，使用

randomSeed（）

使用相当随机的输入初始化随机数生成器，例如未连接管脚上的analogRead（）。

关于插入电缆时看到的值，它们是否有意义取决于输入引脚的信号。如果存在一些差异，可能值得用示波器查看信号

另外，请参见它是浮动输入。如果一个引脚未连接到任何东西或直接连接到5V电源。 arduino对此有点解释。

有关更多详细信息，请查看维基百科，我有PPG传感器板和Arduino Mega。我在我的工具上试过你的密码。当PPG传感器板检测到我的心率时，它开始变为全零。让我解释一下串行监视器的输出。首先，到处都是0。我的心率被检测到了。现在不是0。它充满了数字。这些不仅仅是噪音。这些是我现在的噪音+真实心率数字。我猜Arduino在它的探测频率上显示了图形峰值