python通过com串口连接硬件

使用python是通过com串口连接硬件设备

注意点

1.首先安装serial库，可以运行pip insatll pyserial或在ide上安装

2.Serial()方法参数

Port:串口号；

Baudrate:波特率

Parity:奇偶校验位

Bytesize:数据位

3.由于串口使用的是字节，故而要进行转码，否则串口会不识别

 

此处贴核心代码：

 

import threading

import time

import serial

import logging

 

class ComThread:

    def __init__(self, Port='COM3',Baudrate=115200,Parity=serial.PARITY_NONE,Bytesize=serial.EIGHTBITS):

        # 构造串口的属性

        self.l_serial = None

        self.thread_read = None

        self.alive = False

        self.waitEnd = None

        # 串口号

        self.port = Port

        # 波特率

        self.baudrate = Baudrate

        # 校验位

        self.parity = Parity

        # 数据位

        self.bytesize = Bytesize

        self.ID = None

        self.data = None

        self.device_name = ''

 

    # 定义串口等待的函数

    def waiting(self):

        logging.debug("定义串口等待的函数")

        if not self.waitEnd is None:

            self.waitEnd.wait()

 

    def SetStopEvent(self):

        logging.debug("设置stop event")

        if not self.waitEnd is None:

            self.waitEnd.set()

        self.alive = False

        self.stop()

 

    # 启动串口的函数

    def start(self):

        try:

            logging.debug("启动串口的函数")

            self.l_serial = serial.Serial()

            self.l_serial.port = self.port

            self.l_serial.baudrate = self.baudrate

            self.l_serial.parity = self.parity

            self.l_serial.bytesize = self.bytesize

            # 设置等待时间，若超出这停止等待

            logging.debug("设置等待时间，若超出这停止等待")

            self.l_serial.timeout = 2

            logging.debug('参数--串口：'+str(self.port)+',位/秒：'+str(self.baudrate)+',奇偶校验：'+str(self.parity)+',数据位：'+str(self.bytesize))

            self.l_serial.open()

            # 判断串口是否已经打开

            logging.debug("判断串口是否已经打开:"+str(self.l_serial.isOpen()))

            if self.l_serial.isOpen():

                # 这里写自己的逻辑，我这里是开了一个线程监听串口读数据

                self.waitEnd = threading.Event()

                self.alive = True

                self.thread_read = None

                logging.debug("激活标志alive:" + str(self.alive))

                self.thread_read = threading.Thread(target=self.FirstReader)

                self.thread_read.setDaemon(True)

                self.thread_read.start()

                logging.debug("线程启动。。。")

                return True

            else:

                return False

        except Exception as e:

            logging.debug(str(self.port)+"开启异常："+str(e))

            return False

    # 发送数据

    def SendDate(self,i_msg,send):

        lmsg = ''

        isOK = False

        if isinstance(i_msg):

            lmsg = i_msg.encode('gb18030')

        else:

            lmsg = i_msg

        try:

            # 发送数据到相应的处理组件

            self.l_serial.write(send)

        except Exception as ex:

            pass;

        return isOK

 

 

    def FirstReader(self):

        logging.debug(":数据监控开始。。。")

        # num = 0

        data = ''

        bytes_data = ''.encode('utf-8')

        try:

            while self.alive:

                time.sleep(0.2)

                tmp_data = ''

                tmp_data = tmp_data.encode('utf-8')  # 由于串口使用的是字节，故而要进行转码，否则串口会不识别

                n = self.l_serial.inWaiting()  # 获取接收到的数据长度

                if n == 0:

                    self.data = data

                    bytes_data = b''

                    data = ''

                    continue

                logging.debug("获取接收到的数据长度："+str(n))

                if n:

                    # 读取数据并将数据存入data

                    # print(self.l_serial.read(n))

                    tmp_data = tmp_data + self.l_serial.read(n)

                    # 输出接收到的数据

                    logging.debug('get data from serial port:'+str(tmp_data))

                    # 显示data的类型，便于如果出错时检查错误

                    logging.debug('输出数据的数据类型:' + str(type(tmp_data)))

 

                # 获取还没接收到的数据长度

                n = self.l_serial.inWaiting()

                # 判断是否已经将下位机传输过来的数据全部提取完毕，防止之前没有获取全部数据

                logging.debug('获取还没接收到的数据长度:' + str(n))

                bytes_data = bytes_data + tmp_data

                data = data + str(tmp_data)

        except Exception as e:

            logging.debug('获取com数据异常：'+str(e))

        self.waitEnd.set()

        self.alive = False

 

    def stop(self):

        try:

            self.alive = False

            self.is_send = False

            self.data = None

            if self.thread_read is not None:

                self.thread_read.join()

                logging.debug(str(self.thread_read.ident) + '线程关闭。。。')

 

            if self.l_serial is not None and self.l_serial.isOpen():

                self.l_serial.close()

                logging.debug(str(self.l_serial.port) + '串口关闭。。。')

        except Exception as e:

            logging.debug('关闭'+str(self.port)+'线程失败：'+str(e))

 

写得比较粗糙，望见谅