Question

I m trying to run this example program from the PySerial Documentation for opening serial ports. Source: http://pyserial.sourceforge.net/shortintro.html I tried running the code in both python version 2.7 and 3.4 but still get same error.

>>> import serial
>>> ser = serial.Serial(0)  # open first serial port
>>> print ser.name          # check which port was really used
>>> ser.write("hello")      # write a string
>>> ser.close()             # close port

在操作第二行的法典后,我有以下错误:

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    ser = serial.Serial(0)
  File "C:Python27libsite-packagesserialserialwin32.py", line 38, in __init__
    SerialBase.__init__(self, *args, **kwargs)
  File "C:Python27libsite-packagesserialserialutil.py", line 282, in __init__
    self.open()
  File "C:Python27libsite-packagesserialserialwin32.py", line 66, in open
    raise SerialException("could not open port %r: %r" % (self.portstr,     ctypes.WinError()))
SerialException: could not open port  COM1 : WindowsError(2,  The system cannot find the file specified. )

Answer 1

It sounds like COM1 is not available (it doesn t exist or it s already being used). I made this little scripts for listing available COM ports.

import serial
ser=serial.Serial()
for ns in xrange(101): 
    try:
        ser.port=ns
        ser.open()
        print "COM"+str(ns+1)+" available"
        ser.close()

    except serial.SerialException:
        print "COM"+str(ns+1)+" NOT available"

认为COM港号是你通过序列+1(0)的序号为COM1,序列号。 Serial(1) 开放COM2等

友情链接