Question

如何用python写个串口通信的程序

Answer 1

就是打开串口后，启动一个线程来监听串口数据的进入，有数据时，就做数据的处理（也可以发送一个事件，并携带接收到的数据）。
我没有用到串口处理太深的东西。
客户的原程序不能给你，不过我给你改一下吧。
里面的一些东西，已经经过了处理，要运行，可能你要自己改一下，把没有用的东西去掉。
我这里已经没有串口设备了，不能调了，你自己处理一下吧，不过基本的东西已经有了。
=================================================================
#coding=gb18030

import sys,threading,time;
import serial;
import binascii,encodings;
import re;
import socket;

class ReadThread:
def __init__(self, Output=None, Port=0, Log=None, i_FirstMethod=True):
self.l_serial = None;
self.alive = False;
self.waitEnd = None;
self.bFirstMethod = i_FirstMethod;
self.sendport = '';
self.log = Log;
self.output = Output;
self.port = Port;
self.re_num = None;

def waiting(self):
if not self.waitEnd is None:
self.waitEnd.wait();

def SetStopEvent(self):
if not self.waitEnd is None:
self.waitEnd.set();
self.alive = False;
self.stop();

def start(self):
self.l_serial = serial.Serial();
self.l_serial.port = self.port;
self.l_serial.baudrate = 9600;
self.l_serial.timeout = 2;

self.re_num = re.compile('\d');

try:
if not self.output is None:
self.output.WriteText(u'打开通讯端口\r\n');
if not self.log is None:
self.log.info(u'打开通讯端口');
self.l_serial.open();
except Exception, ex:
if self.l_serial.isOpen():
self.l_serial.close();

self.l_serial = None;

if not self.output is None:
self.output.WriteText(u'出错：\r\n %s\r\n' % ex);
if not self.log is None:
self.log.error(u'%s' % ex);
return False;

if self.l_serial.isOpen():
if not self.output is None:
self.output.WriteText(u'创建接收任务\r\n');
if not self.log is None:
self.log.info(u'创建接收任务');
self.waitEnd = threading.Event();
self.alive = True;
self.thread_read = None;
self.thread_read = threading.Thread(target=self.FirstReader);
self.thread_read.setDaemon(1);
self.thread_read.start();
return True;
else:
if not self.output is None:
self.output.WriteText(u'通讯端口未打开\r\n');
if not self.log is None:
self.log.info(u'通讯端口未打开');
return False;

def InitHead(self):
#串口的其它的一些处理
try:
time.sleep(3);
if not self.output is None:
self.output.WriteText(u'数据接收任务开始连接网络\r\n');
if not self.log is None:
self.log.info(u'数据接收任务开始连接网络');
self.l_serial.flushInput();
self.l_serial.write('\x11');
data1 = self.l_serial.read(1024);
except ValueError,ex:
if not self.output is None:
self.output.WriteText(u'出错：\r\n %s\r\n' % ex);
if not self.log is None:
self.log.error(u'%s' % ex);
self.SetStopEvent();
return;

if not self.output is None:
self.output.WriteText(u'开始接收数据\r\n');
if not self.log is None:
self.log.info(u'开始接收数据');
self.output.WriteText(u'===================================\r\n');

def SendData(self, i_msg):
lmsg = '';
isOK = False;
if isinstance(i_msg, unicode):
lmsg = i_msg.encode('gb18030');
else:
lmsg = i_msg;
try:
#发送数据到相应的处理组件
pass
except Exception, ex:
pass;
return isOK;

def FirstReader(self):
data1 = '';
isQuanJiao = True;
isFirstMethod = True;
isEnd = True;
readCount = 0;
saveCount = 0;
RepPos = 0;
#read Head Infor content
self.InitHead();

while self.alive:
try:
data = '';
n = self.l_serial.inWaiting();
if n:
data = data + self.l_serial.read(n);
#print binascii.b2a_hex(data),

for l in xrange(len(data)):
if ord(data[l])==0x8E:
isQuanJiao = True;
continue;
if ord(data[l])==0x8F:
isQuanJiao = False;
continue;
if ord(data[l]) == 0x80 or ord(data[l]) == 0x00:
if len(data1)>10:
if not self.re_num.search(data1,1) is None:
saveCount = saveCount + 1;
if RepPos==0:
RepPos = self.output.GetInsertionPoint();
self.output.Remove(RepPos,self.output.GetLastPosition());

self.SendData(data1);
data1 = '';
continue;
except Exception, ex:
if not self.log is None:
self.log.error(u'%s' % ex);

self.waitEnd.set();
self.alive = False;

def stop(self):
self.alive = False;
self.thread_read.join();
if self.l_serial.isOpen():
self.l_serial.close();
if not self.output is None:
self.output.WriteText(u'关闭通迅端口：[%d] \r\n' % self.port);
if not self.log is None:
self.log.info(u'关闭通迅端口：[%d]' % self.port);

def printHex(self, s):
s1 = binascii.b2a_hex(s);
print s1;

#测试用部分
if __name__ == '__main__':
rt = ReadThread();
f = open("sendport.cfg", "r")
rt.sendport = f.read()
f.close()
try:
if rt.start():
rt.waiting();
rt.stop();
else:
pass;
except Exception,se:
print str(se);

if rt.alive:
rt.stop();

print 'End OK .';
del rt;