FastGPIO::PinLoan< pin > Class Template Reference

#include <FastGPIO.h>

Public Member Functions
	PinLoan ()
	~PinLoan ()

Data Fields
uint8_t	state
	The state of the pin as returned from FastGPIO::Pin::getState. More...

Detailed Description

template<uint8_t pin>
class FastGPIO::PinLoan< pin >

This class saves the state of the specified pin in its constructor when it is created, and restores the pin to that state in its destructor. This can be very useful if a pin is being used for multiple purposes. It allows you to write code that temporarily changes the state of the pin and is guaranteed to restore the state later.

For example, if you were controlling both a button and an LED using a single pin and you wanted to see if the button was pressed without affecting the LED, you could write:

bool buttonIsPressed()
{
    FastGPIO::PinLoan<IO_D5> loan;
    FastGPIO::Pin<IO_D5>::setInputPulledUp();
    _delay_us(10);
    return !FastGPIO::Pin<IO_D5>::isInputHigh();
}

This is equivalent to:

bool buttonIsPressed()
{
    uint8_t state = FastGPIO::Pin<IO_D5>::getState();
    FastGPIO::Pin<IO_D5>::setInputPulledUp();
    _delay_us(10);
    bool value = !FastGPIO::Pin<IO_D5>::isInputHigh();
    FastGPIO::Pin<IO_D5>::setState(state);
    return value;
}

Definition at line 484 of file FastGPIO.h.

Constructor & Destructor Documentation

PinLoan()

template<uint8_t pin>

FastGPIO::PinLoan< pin >::PinLoan ( )

inline

Definition at line 490 of file FastGPIO.h.

References FastGPIO::Pin< pin >::getState(), and FastGPIO::PinLoan< pin >::state.

~PinLoan()

template<uint8_t pin>

FastGPIO::PinLoan< pin >::~PinLoan ( )

inline

Definition at line 495 of file FastGPIO.h.

References FastGPIO::Pin< pin >::setState(), and FastGPIO::PinLoan< pin >::state.

Field Documentation

state

template<uint8_t pin>

uint8_t FastGPIO::PinLoan< pin >::state

The state of the pin as returned from FastGPIO::Pin::getState.

Definition at line 488 of file FastGPIO.h.

Referenced by FastGPIO::PinLoan< pin >::PinLoan(), and FastGPIO::PinLoan< pin >::~PinLoan().

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The documentation for this class was generated from the following file:

• src/FastGPIO.h