这篇文章主要介绍了Python之PyQT多线程串口代码分析,小编觉得挺不错的，现在分享给大家，也给大家做个参考。一起跟随小编过来看看吧
这篇博客主要记录一下pyqt多线程串口的主要代码分析，文末会有工程的源代码文件
首先，从pycharm启动qtdesigner
之前给客户做的上位机，保密起见，删减了大部分的框图构件，但不影响本篇串口教程
QtDesigner界面如下：
忽略 添加数据以及表格数据显示，这里用不到
着重讲一下类的构成
新建一个串口类SerialThread，继承自QtCore.QThread，实现全部的串口收发功能
class SerialThread(QtCore.QThread):
dataReadoutSignal = pyqtSignal(str) def __init__(self, parent = None, portName = 'COM3', baudrate = 9600, parity = 'N', bytesize = 8, stopbits = 1, timeout = None):
super(SerialThread, self).__init__(parent)
self.m_serialPort = serial.Serial()
self.m_serialPort.port = portName
self.m_serialPort.baudrate = baudrate
self.m_serialPort.parity = parity
self.m_serialPort.bytesize = bytesize
self.m_serialPort.stopbits = stopbits
self.m_serialPort.timeout = timeout
self.OpenScom() def OpenScom(self):
try:
self.m_serialPort.open()
self.m_serialPort.setRTS(True)
self.m_serialPort.setDTR(True) except Exception as ex:
print(ex) return ex def ScomSendOneData(self,datain):
if isinstance(datain,int):
listTemp = []
listTemp.append(datain)
d = bytes(listTemp)
self.m_serialPort.write(d) else: if isinstance(datain,str):
d = datain.encode('utf-8')
self.m_serialPort.write(d) def ScomGetintData(self):
n = self.m_serialPort.inWaiting() if n:
data = self.m_serialPort.read(n).hex() #writefile
print(data) def ScomGetstrData(self):
if self.m_serialPort.is_open:
n = self.m_serialPort.inWaiting() if n > 0:
data = self.m_serialPort.read(n).decode('GB2312',errors='ignore') return data def run(self):
cnt = 50
while cnt <= 3000:
sendstr = str(cnt) if len(sendstr) == 2:
sendstr = '00' + sendstr else: if len(sendstr) == 3:
sendstr = '0' + sendstr
self.ScomSendOneData('SET' + sendstr + 'V')
cnt = cnt + 5
print('此时设置电压为：' + sendstr + 'V')
time.sleep(2)函数功能见名知意，此处不表。这里主要讲一下run函数，run函数实现了一次循环，50到3000步进取5，发送内容是SET0050V到SET3000V，当然，我这样做是业务需求，如果并不需要这个功能，run函数可以写成
def run(self):
while true:
time.sleep(2)界面我们用QtDesigner制作的ui文件通过pyUIC生成py文件
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生成的代码如下（太长，只留前几行）
# -*- coding: utf-8 -*-# Form implementation generated from reading ui file 'CashUpdateUI11v.ui'## Created by: PyQt5 UI code generator 5.6## WARNING! All changes made in this file will be lost!from PyQt5 import QtCore, QtGui, QtWidgetsclass Ui_cash(object):
def setupUi(self, cash):
**
**
**此时，新建一个类MyWindow，继承QMainWindow和Ui_cash，并在类内部，创建SerialThread成员
总体代码如下：
class MyWindow(QMainWindow,Ui_cash):
def __init__(self):
super(MyWindow,self).__init__()
self.scomList = []
self.threadList = []
self.setupUi(self)
self.actionOpen.triggered.connect(self.openMsg)
self.actionSave.triggered.connect(self.saveMsg)
self.pushButton.clicked.connect(self.ScomAutoFind)
self.addDataButton.clicked.connect(self.getRHandT)
self.tableWidget.setColumnCount(5)
self.tableWidget.setRowCount(1)
self.tableWidget.setHorizontalHeaderLabels(['11', '22', '33', '44', '55'])
self.tableRowCnt = 0
self.tableColumnCnt = 0
self.ThreadComID = 0
self.addDatasignal = pyqtSignal(str)
self.datadict = {'RHldy':0,'Tldy':0,'meaRT':0,'voltport':0} def getMCUdata(self):
if self.ThreadComID == 0:
self.showMsgbox('请先连接串口') else:
self.ThreadComID.ScomSendOneData(' 5501AA')
time.sleep(0.1)
strt = self.ThreadComID.ScomGetstrData() if strt is None:
self.showMsgbox('请将串口线连接到电路板') return None
print(strt)
self.datadict['voltport'] = strt[4:-3] + '.' + strt[-3:-2]
self.ThreadComID.ScomSendOneData(' 5502AA')
time.sleep(0.1)
strt = self.ThreadComID.ScomGetstrData() if strt is None:
self.showMsgbox('请将串口线连接到电路板') return None
print(strt)
self.datadict['meaRT'] = strt[4:-4] + '.' + strt[-4:-2] return 1
def insertTableNewLine(self):
self.tableWidget.setItem(self.tableRowCnt, 0, QTableWidgetItem(self.datadict['RHldy']))
self.tableWidget.setItem(self.tableRowCnt, 1, QTableWidgetItem(self.datadict['Tldy']))
self.tableWidget.setItem(self.tableRowCnt, 2, QTableWidgetItem(self.datadict['meaRT']))
self.tableWidget.setItem(self.tableRowCnt, 3, QTableWidgetItem(self.datadict['voltport']))
self.tableWidget.setItem(self.tableRowCnt, 4, QTableWidgetItem(str(datetime.date.today())+' '+str(datetime.datetime.today().hour)+':'+str(datetime.datetime.today().minute)))
self.tableRowCnt += 1
self.tableWidget.insertRow(self.tableRowCnt) def openMsg(self):
file,ok = QFileDialog.getOpenFileName(self,"打开记录表","C:/",".txt") def getRHandT(self):
if self.ThreadComID == 0:
self.showMsgbox('请先连接串口') else:
data,ok = QInputDialog.getText(self, "露点仪数据", "按如下格式记录：\n RH空格T\n示例：\n RH(0~100):66.6\n T(0~200):9.8\n 输入：66.6 9.8", QLineEdit.Normal, "66.6 9.8" ) if ok == True:
data = re.findall('^[0-9]+\.[0-9]+\s+[0-9]+\.[0-9]+$', data.rstrip()) if len(data) == 0:
self.showMsgbox('数据格式有误，重新录入') else:
data = data[0].split()
print(data)
self.datadict['RHldy'] = data[0]
self.datadict['Tldy'] = data[1] if self.getMCUdata() is None: return None
print(self.datadict)
self.insertTableNewLine() else:
self.showMsgbox('请重新录入数据') def showMsgbox(self,strtoshow):
QMessageBox.warning(self,'提示',strtoshow,QMessageBox.Ok) def saveMsg(self):
file,ok = QFileDialog.getSaveFileName(self,"保存记录表","C:/",".txt") def ScomAutoFind(self):
self.pushButton.setDisabled(True)
self.scomList = list(serial.tools.list_ports.comports()) if len(self.scomList) <= 0:
self.showMsgbox('未发现串口，请检查线缆连接')
self.pushButton.setDisabled(False) else:
comNum = len(self.scomList)
print(str(comNum) + 'Scom is found') while comNum:
comNum = comNum - 1
if "USB" in str(self.scomList[comNum]):
self.ThreadComID = SerialThread(portName=self.scomList[comNum][0])
self.ThreadComID.start()
self.graphicsView.setStyleSheet("background-color: rgb(0, 255, 0);")
print(str(self.scomList[comNum]) + ' is added')由于我用的是RS232转USB接入电脑，设备名称是USB-SERIAL CH340，当然还有其他RS232转USB芯片，如PL2303等。我这里就单独检查USB是否在设备名称中，没有检查全名，这里要根据实际需求变动 
最后就是main了，没什么特别
if __name__ == "__main__":
app = QApplication(sys.argv)
myshow = MyWindow()
myshow.show() print('程序终止')
sys.exit(app.exec_())看一下实际运行效果：
实际运行，（忽略 添加数据 与 数据记录表….） 
点击connect后， 
当然点击添加数据也是没问题的哈 
奉上全部工程文件，链接如下：
https://download.csdn.net/download/ysgjiangsu/10324162
