十二、Qt之串口開發

主要是藉助第三方庫 qextserialport

#include "qextserialport.h"
QextSerialPort *com;        //串口通信對象

/**
 * @brief 讀取串口數據
 */
void frmComTool::readData()
{
    if (com->bytesAvailable() <= 0) {
        return;
    }

    QUIHelper::sleep(sleepTime);
    QByteArray data = com->readAll();
    int dataLen = data.length();
    if (dataLen <= 0) {
        return;
    }

    if (isShow) {
        QString buffer;
        if (ui->ckHexReceive->isChecked()) {
            buffer = QUIHelper::byteArrayToHexStr(data);
        } else {
            //buffer = QUIHelper::byteArrayToAsciiStr(data);
            buffer = QString::fromLocal8Bit(data);
        }

        //啓用調試則模擬調試數據
        if (ui->ckDebug->isChecked()) {
            int count = App::Keys.count();
            for (int i = 0; i < count; i++) {
                if (buffer.startsWith(App::Keys.at(i))) {
                    sendData(App::Values.at(i));
                    break;
                }
            }
        }

        append(1, buffer);
        receiveCount = receiveCount + data.size();
        ui->btnReceiveCount->setText(QString("接收 : %1 字節").arg(receiveCount));
    }
}

/**
 * @brief 發送串口數據帶參數
 */
void frmComTool::sendData(QString data)
{
    if (com == 0 || !com->isOpen()) {
        return;
    }

    //短信貓調試
    if (data.startsWith("AT")) {
        data += "\r";
    }

    QByteArray buffer;

    if (ui->ckHexSend->isChecked()) {
        buffer = QUIHelper::hexStrToByteArray(data);
    } else {
        buffer = QUIHelper::asciiStrToByteArray(data);
    }

    com->write(buffer);
    append(0, data);
    sendCount = sendCount + buffer.size();
    ui->btnSendCount->setText(QString("發送 : %1 字節").arg(sendCount));
}

/**
 * @brief 打開串口
 */
void frmComTool::on_btnOpen_clicked()
{
    if (ui->btnOpen->text() == "打開串口") {
        com = new QextSerialPort(ui->cboxPortName->currentText(), QextSerialPort::Polling);
        comOk = com->open(QIODevice::ReadWrite);

        if (comOk) {
            //清空緩衝區
            com->flush();
            //設置波特率
            com->setBaudRate((BaudRateType)ui->cboxBaudRate->currentText().toInt());
            //設置數據位
            com->setDataBits((DataBitsType)ui->cboxDataBit->currentText().toInt());
            //設置校驗位
            com->setParity((ParityType)ui->cboxParity->currentIndex());
            //設置停止位
            com->setStopBits((StopBitsType)ui->cboxStopBit->currentIndex());
            com->setFlowControl(FLOW_OFF);
            com->setTimeout(10);

            changeEnable(true);
            ui->btnOpen->setText("關閉串口");
            timerRead->start();
        }
    } else {
        timerRead->stop();
        com->close();
        com->deleteLater();
        
        changeEnable(false);
        ui->btnOpen->setText("打開串口");
        on_btnClear_clicked();
        comOk = false;
    }
}

參見 關於QT串口通信的一點理解