digitalRead()

[Digital I/O]

描述

Reads the value from a specified digital pin, either HIGH 或 LOW.

語法

digitalRead(pin)

參數

pin: the number of the digital pin you want to read (int)

回傳

HIGH 或 LOW

範例程式碼

Sets pin 13 to the same value as pin 7, declared as an input.

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
}

Notes

If the pin isn’t connected to anything, digitalRead() can return either HIGH 或 LOW (and this can change randomly).

Unlike Arduino, the analog input pins (referred to as A0, A1, etc) of 86Duino cannot be used as digital pins.

參考

• [程式語法] pinMode()
• [程式語法] digitalWrite()

語法參考主頁面

The text of the 86Duino reference is a modification of the Arduino reference and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.