DigitalIn Class Reference

A digital input, used for reading the state of a pin. More...

#include <DigitalIn.h>

Public Member Functions
	DigitalIn (PinName pin)
	Create a DigitalIn connected to the specified pin. More...
	DigitalIn (PinName pin, PinMode mode)
	Create a DigitalIn connected to the specified pin. More...
	~DigitalIn ()
	Class destructor, deinitialize the pin. More...
int	read ()
	Read the input, represented as 0 or 1 (int) More...
void	mode (PinMode pull)
	Set the input pin mode. More...
int	is_connected ()
	Return the output setting, represented as 0 or 1 (int) More...
	operator int ()
	An operator shorthand for read() More...

Detailed Description

A digital input, used for reading the state of a pin.

Note

Synchronization level: Interrupt safe

Example:

// Flash an LED while a DigitalIn is true
 
#include "mbed.h"
 
DigitalIn enable(p5);
DigitalOut led(LED1);
 
int main() {
    while(1) {
        if(enable) {
            led = !led;
        }
        ThisThread::sleep_for(250);
    }
}

Definition at line 56 of file DigitalIn.h.

Constructor & Destructor Documentation

DigitalIn() [1/2]

DigitalIn

(

PinName

pin

)

Create a DigitalIn connected to the specified pin.

Parameters

pin	DigitalIn pin to connect to

Definition at line 67 of file DigitalIn.h.

DigitalIn() [2/2]

DigitalIn	(	PinName	pin,
		PinMode	mode
	)

Create a DigitalIn connected to the specified pin.

Parameters

pin	DigitalIn pin to connect to
mode	the initial mode of the pin

Definition at line 78 of file DigitalIn.h.

~DigitalIn()

~DigitalIn

(

)

Class destructor, deinitialize the pin.

Definition at line 86 of file DigitalIn.h.

Member Function Documentation

read()

int read

(

)

Read the input, represented as 0 or 1 (int)

Returns

An integer representing the state of the input pin, 0 for logical 0, 1 for logical 1

Definition at line 97 of file DigitalIn.h.

mode()

void mode

(

PinMode

pull

)

Set the input pin mode.

Parameters

pull	PullUp, PullDown, PullNone, OpenDrain

is_connected()

int is_connected

(

)

Return the output setting, represented as 0 or 1 (int)

Returns

Non zero value if pin is connected to uc GPIO 0 if gpio object was initialized with NC

Definition at line 114 of file DigitalIn.h.

operator int()

operator int

(

)

An operator shorthand for read()

See also

DigitalIn::read()

DigitalIn  button(BUTTON1);
DigitalOut led(LED1);
led = button;   // Equivalent to led.write(button.read())

Definition at line 128 of file DigitalIn.h.