Qt上位机串口通信调试记录
开发环境
- 系统版本：Windows 10
- 开发工具：VS2013+Qt5.4.2
- 串口类库：第三方串口类qextserialport-1.2win-alpha（下载地址：https://sourceforge.net/projects/qextserialport/?source=directory）
qextserialport目录
-
目录结构
- windows平台下用到的文件
串口设置
- 初始化对象
if (Singleton::getInstance()->m_extSerialPort == NULL)
{
Singleton::getInstance()->m_extSerialPort = new Win_QextSerialPort(ui->comboBox_SerialPort->currentText(),QextSerialBase::EventDriven);
}
else
{
Singleton::getInstance()->m_extSerialPort->close();
}
Singleton::getInstance()->m_extSerialPort->setPortName(ui->comboBox_SerialPort->currentText());
- 参数设置及打开
if (Singleton::getInstance()->m_extSerialPort != NULL)
{
if (Singleton::getInstance()->m_extSerialPort->open(QIODevice::ReadWrite))
{
Singleton::getInstance()->m_extSerialPort->setBaudRate(BAUD115200);//波特率设置，设为115200
Singleton::getInstance()->m_extSerialPort->setDataBits(DATA_8);//数据位设置，设为8位
Singleton::getInstance()->m_extSerialPort->setParity(PAR_NONE);//奇偶校验设置，设为无校验
Singleton::getInstance()->m_extSerialPort->setStopBits(STOP_1);//停止位设置，设为1位停止位
Singleton::getInstance()->m_extSerialPort->setFlowControl(FLOW_OFF);//控制流设置，设为无控制流
}
}串口写操作
char *sendBuffer = (char*)malloc(FrameLengthWithoutData + 3 +2);//定义发送数组
SerialPortProtocol::CodingSerialport(sendBuffer, SystemConfig, Handshaking, Request, 0);//通信帧封装
sendBuffer[FrameLengthWithoutData + 3] = 0x0d;//帧尾添加0d 0a（换行符）
sendBuffer[FrameLengthWithoutData + 3 +1] = 0x0a;//帧尾添加0d 0a（换行符）
Singleton::getInstance()->m_extSerialPort->write(sendBuffer, FrameLengthWithoutData + 3 +2);//发送
备注：帧尾添加换行符，方便下位机界定数据帧结尾
串口读操作
将readyRead信号与自己的串口接收槽函数绑定，即可响应串口读数据事件
connect(Singleton::getInstance()->m_extSerialPort, &Win_QextSerialPort::readyRead, m_receiveSerialportObj, &ReceiveSerialPortThreadObject::receiveRun);
备注：串口读缓冲区一有字符便会触发readyRead信号，为了保证接收数据帧的完整性，接收槽函数可以循环读（将读到的字符暂存在缓冲数组中）直到读到指定长度的字符（或者帧尾字符）
再进行数据帧解码工作，代码如下
if (Singleton::getInstance()->m_extSerialPort->bytesAvailable() >0)
{
char readbuf[MaxDataLen];
int byte_size = Singleton::getInstance()->m_extSerialPort->readLine(readbuf, MaxDataLen);
if (readbuf[byte_size - 2] != 0x0d || readbuf[byte_size - 1] != 0x0a)
{
bool flag = readbuf[byte_size - 2] == 0x0d && readbuf[byte_size - 1] == 0x0a;
while (!flag)
{
if (Singleton::getInstance()->m_extSerialPort->bytesAvailable() > 0)
{
byte_size += Singleton::getInstance()->m_extSerialPort->readLine(readbuf + byte_size, MaxDataLen);
}
flag = readbuf[byte_size - 2] == 0x0d && readbuf[byte_size - 1] == 0x0a;
}
}
if (byte_size >= (FrameLengthWithoutData + 3 + 2))
{
int datalen = byte_size - FrameLengthWithoutData - 2 - 3;
char* data = (char*)malloc(datalen);
memset(data, 0, datalen);
int leve1comm, leve2comm, flag, curfram, totalfram, device;
if (SerialPortProtocol::DecodingSerialport(readbuf, byte_size - 2, data, &leve1comm, &leve2comm, &flag, &datalen, &curfram, &totalfram, &device))
serialcommand(device, curfram, totalfram, leve1comm, leve2comm, flag, QString(data));
//QString mess(data);
//emit message(mess);
delete data;
}
}