This reference is for Processing 3.0+. If you have a previous version, use the reference included with your software in the Help menu. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Core Javadoc and Libraries Javadoc.
| Class | |||
|---|---|---|---|
| Name | digitalRead() |
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| Examples |
import processing.io.*;
// On the Raspberry Pi GPIO 4 is physical pin 7 on the header
void setup() {
// INPUT_PULLUP enables the built-in pull-up resistor for this pin
// left alone, the pin will read as HIGH
// connected to ground (via e.g. a button or switch) it will read LOW
GPIO.pinMode(4, GPIO.INPUT_PULLUP);
}
void draw() {
if (GPIO.digitalRead(4) == GPIO.LOW) {
// button is pressed
fill(255);
} else {
// button is not pressed
fill(204);
}
stroke(255);
ellipse(width/2, height/2, width*0.75, height*0.75);
}
| ||
| Description |
Returns the value of an input pin, which is either GPIO.HIGH (1) or GPIO.LOW (0) You need to set the pin to input by calling pinMode() before calling this function. |
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| Syntax | .digitalRead(pin) | ||
| Parameters |
| ||
| Returns | int |
