pyserial problem: script stops reading

[Steve Holden]

Frederic Wenzel wrote:
> On 9/9/06, Frederic Wenzel <freeed at gmail.com> wrote:
> 
>>On 9/9/06, Hendrik van Rooyen <mail at microcorp.co.za> wrote:
>>
>>>| I wrote a script on Linux that uses pyserial to read status messages
>>>| from a serial line using readlines(). For now, it just displays what
>>>| it gets on stdout:
>>>| (...)
>>>| ser = serial.Serial(port=1,
>>>|                                  baudrate=1200,
>>>|                                  rtscts=1,
>>>|
>>>| If the script does not time out there, I am not sure what else it is
>>>| doing. It seems to be in a wait state it does not get out of.
> 
> 
> When it stopped working again (unfortunately) I pressed ctrl c and got
> the following outputÖ
> 
> 14:53 | 0008 | 02 |   | 5  |Rack Abs.|  -  | --752
> 14:53 | 0005 | 02 |   | 2  |Rack Abs.|  -  | 00752
> 14:53 | 0008 | 02 |Traceback (most recent call last):
>   File "serialhandler.py", line 34, in ?
>     lines = sh.readLines()
>   File "serialhandler.py", line 29, in readLines
>     return self.ser.readlines()
>   File "/usr/lib/python2.3/site-packages/serial/serialutil.py", line
> 78, in readlines
>     line = self.readline(eol=eol)
>   File "/usr/lib/python2.3/site-packages/serial/serialutil.py", line
> 60, in readline
>     c = self.read(1)
>   File "/usr/lib/python2.3/site-packages/serial/serialposix.py", line
> 269, in read
>     ready,_,_ = select.select([self.fd],[],[], self._timeout)
> KeyboardInterrupt
> 
> 
> Apparently this is the place where it gets stuck. The select.select
> line does not return, not even for a timeout.
> 
> Fred
Try running your program with

     python -i [programname.py]

That way after you ^C it you'll be able to poke around a bit in an 
interactive shell (though I suspect that the stackframe contents will 
have been lost, so you'll only have globals to look at - that may or may 
not be enough).

regards
  Steve
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