Qt：在树莓配中控制gpio阵脚

关于树莓派的介绍这里不做描述，关于gpio更多的信息可以移步：

http://www.cnblogs.com/vamei/p/6751992.html

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写了一个简单的demo，控制20号针脚，直接上代码：

jqgpio.h：

#ifndef JQGPIO_H_#define JQGPIO_H_// Qt lib import#include <QObject>#include <QMutex>class JQGpio{private:    JQGpio() = default;public:    ~JQGpio() = default;    static bool exportGpio(const int &portId, const bool &isOutPort);    static bool unexportGpio(const int &portId);    static QPair< bool, bool > readGpio(const int &portId);    static bool writeGpio(const int &portId, const bool &state);    static QString gpioExportFilePath();    static QString gpioUnexportFilePath();    static QString gpioDirectionFilePath(const int &portId);    static QString gpioValueFilePath(const int &portId);private:    static QMutex mutex_;};#endif//JQGPIO_H_

jqgpio.cpp：

#include "jqgpio.h"// Qt lib import#include <QDebug>#include <QFile>#include <QThread>QMutex JQGpio::mutex_;bool JQGpio::exportGpio(const int &portId, const bool &isOutPort){    mutex_.lock();    {        QFile file( gpioExportFilePath() );        if ( !file.open( QIODevice::WriteOnly ) )        {            mutex_.unlock();            return false;        }        if ( !file.write( QString( "%1\n" ).arg( portId ).toLatin1() ) )        {            mutex_.unlock();            return false;        }        file.waitForBytesWritten( 5000 );    }    {        for ( auto tryCount = 0; tryCount < 5; ++tryCount )        {            QThread::msleep( 100 );            if ( QFile( gpioDirectionFilePath( portId ) ).exists() )            {                break;            }            if ( tryCount == 4 )            {                qDebug() << "JQGpio::exportGpio: direction not exist error:" << portId;                mutex_.unlock();                return false;            }        }        QFile file( gpioDirectionFilePath( portId ) );        if ( !file.open( QIODevice::WriteOnly ) )        {            mutex_.unlock();            return false;        }        if ( isOutPort )        {            if ( !file.write( "out\n" ) )            {                mutex_.unlock();                return false;            }        }        else        {            if ( !file.write( "in\n" ) )            {                mutex_.unlock();                return false;            }        }        file.waitForBytesWritten( 5000 );    }    mutex_.unlock();    return true;}bool JQGpio::unexportGpio(const int &portId){    mutex_.lock();    QFile file( gpioUnexportFilePath() );    if ( !file.open( QIODevice::WriteOnly ) )    {        mutex_.unlock();        return false;    }    if ( !file.write( QString( "%1\n" ).arg( portId ).toLatin1() ) )    {        mutex_.unlock();        return false;    }    file.waitForBytesWritten( 5000 );    mutex_.unlock();    return true;}QPair< bool, bool > JQGpio::readGpio(const int &portId){    QFile file( gpioValueFilePath( portId ) );    if ( !file.open( QIODevice::ReadOnly ) ) { return { false, false }; }    const auto &&data = file.readAll();    if ( data.startsWith( "0" ) ) { return { true, false }; }    if ( data.startsWith( "1" ) ) { return { true, true }; }    return { false, false };}bool JQGpio::writeGpio(const int &portId, const bool &state){    QFile file( gpioValueFilePath( portId ) );    if ( !file.open( QIODevice::WriteOnly ) ) { return false; }    if ( state )    {        if ( !file.write( "1\n" ) ) { return false; }    }    else    {        if ( !file.write( "0\n" ) ) { return false; }    }    file.waitForBytesWritten( 5000 );    return true;}QString JQGpio::gpioExportFilePath(){    return QString( "/sys/class/gpio/export" );}QString JQGpio::gpioUnexportFilePath(){    return QString( "/sys/class/gpio/unexport" );}QString JQGpio::gpioDirectionFilePath(const int &portId){    return QString( "/sys/class/gpio/gpio%1/direction" ).arg( portId );}QString JQGpio::gpioValueFilePath(const int &portId){    return QString( "/sys/class/gpio/gpio%1/value" ).arg( portId );}

main.cpp：

// Qt lib import#include <QCoreApplication>#include <QDebug>#include <QThread>// JQLibrary lib import#include "jqgpio.h"int main(int argc, char *argv[]){    QCoreApplication a(argc, argv);    qDebug() << "JQGpio::exportGpio( 20, true ):" << JQGpio::exportGpio( 20, true );    for ( auto i = 0; i < 10; ++i )    {        qDebug() << "JQGpio::writeGpio( 20, true ): "<< JQGpio::writeGpio( 20, true );        QThread::sleep( 1 );        qDebug() << "JQGpio::writeGpio( 20, false ): "<< JQGpio::writeGpio( 20, false );        QThread::sleep( 1 );    }    qDebug() << "JQGpio::unexportGpio( 20 ):" << JQGpio::unexportGpio( 20 );    return 0;}