查看DigitalRead()的源代碼

<pre style="color:blue">
int digitalRead (uint8_t pin)  	
</pre>
讀數(shù)字引腳<br>

讀數(shù)字引腳, 返回引腳的高低電平. 在讀引腳之前, 需要將引腳設(shè)置為INPUT模式.<br>

參數(shù):<br>
*pin 	引腳編號

返回:<br>
HIGH或LOW

<pre style="color:green">
int ledPin = 13; // LED connected to digital pin 13
int inPin = 7;   // pushbutton connected to digital pin 7
int val = 0;     // variable to store the read value

void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin 13 as output
  pinMode(inPin, INPUT);      // sets the digital pin 7 as input
}

void loop()
{
  val = digitalRead(inPin);   // read the input pin
  digitalWrite(ledPin, val);    // sets the LED to the button's value
}
</pre>
注解:<br>
    如果引腳沒有鏈接到任何地方, 那么將隨機返回 HIGH 或 LOW.