Hi Marcus,
Sorry it has taken me a while to reply. I have tested it your
suggestion and of course it works fine. It all seemed so obvious when I
read your reply:)
Another question, I can't get it to stop cacheing. Even following the
example on your web page, I get -
>>> connection = Connection ("/dev/ttyD0")
>>> for s in root.find () : print s
...
<Sensor /10.2054A9010800/ - DS18S20>
<Sensor /10.522FA9010800/ - DS18S20>
<Sensor /28.C0617A020000/ - DS18B20>
<Sensor /28.F26D7A020000/ - DS18B20>
<Sensor /09.2179B9050000/ - DS2502>
>>> s.use_cache (0)
>>> for s in root.find () : print s
...
<Sensor /10.2054A9010800/ - DS18S20>
<Sensor /10.522FA9010800/ - DS18S20>
<Sensor /28.C0617A020000/ - DS18B20>
<Sensor /28.F26D7A020000/ - DS18B20>
<Sensor /09.2179B9050000/ - DS2502>
>>>
So I don't see the /uncached/ entries that I was expecting.
It is not a major problem for me, but I would like to force it to do a
real read every time.
Again, thank you so much for all your help, I have learned a lot about
1-wire and Python over the past few months, still a lot more to learn
though I fear.
Cheers
Mick
On Mon, 2010-05-31 at 23:50 +0200, Marcus Priesch wrote:
> Hi mick,
>
> i am really sorry, but obviously your post scrolled out of my inbox
> view ... and i just forgot it ;)
>
> well, KeyError is the desired behaviour when you do a "get" on a
> "dictionary" like object ... so your code should be prepared for it ;)
>
> as i see aou alread catch the IOError - however i am very unsure why you
> do this ... ?!?! pyowfs shouldnt raise an IOError at all ...
>
> but instead you should watch ot for KeyError whenever accessing an
> attribute from a Sensor ...
>
> e.g.:
>
> @property
> def present (self) :
> try:
> return self.sensor.get ("present")
> except IOError, KeyError:
> return -777
>
> or
>
> @property
> def present (self) :
> try:
> return self.sensor.get ("present")
> except IOError:
> return -777
> except KeyError :
> print "key not found"
> return -888
>
> or simply in your main loop :
>
> s1 = Sens1 (connection)
> s2 = Sens2 (connection)
> while True : # repeat forever
> for s in [s1,s2] :
> try :
> print "reading %r" % s
> print 'temp = ', s.temp
> print 'id = ', s.id
> print 'present = ', s.present
> print 'power = ', s.power
> except KeyError :
> print "something wrong with sensor %r" % s
>
> hope this helps you out ;)
>
> regards,
> marcus.
>
> Am Mittwoch, den 19.05.2010, 23:27 +0100 schrieb Mick Sulley:
> > Hi Marcus,
> >
> > Thanks for your fast response. I just tested version 0.1.3, I now get
> >
> > Start of loop 21530
> > S1 reading
> > temp = 26.5
> > id = 522FA9010800
> > present = 1
> > power = 0
> > S2 reading
> > temp = something wrong with temp
> > None
> > id = 2054A9010800
> > present =
> > Traceback (most recent call last):
> > File "./pyowfs_test1.py", line 72, in <module>
> > print 'present = ', s2.present
> > File "./pyowfs_test1.py", line 36, in present
> > return self.sensor.get ("present")
> > File "/usr/local/lib/python2.6/dist-packages/pyowfs/owfs.py", line 95,
> > in get
> > raise KeyError (key)
> > KeyError: 'present'
> > m...@mick-desktop:~/Documents/Controls$
> >
> >
> > What I am trying to do is to read the data from all the sensor and if
> > one goes missing flag it up somehow, maybe setting the 'present'
> > attribute to zero, but it needs to continue reading the others and if
> > the missing one come back it needs to start reading that one as well.
> >
> > Here is the code that I am using to test, maybe there is a better way to
> > achieve this?
> >
> >
> > #! /usr/bin/env python
> > # Filename pyowfs_test1.py
> > # based up the code from Marcus Priesch
> >
> >
> > from pyowfs import Connection
> > import sys
> >
> > class Sensor (object) :
> > id = None
> > def __init__ (self, connection):
> > self.conn = connection
> > self.sensor = connection.find (id = self.id)[0]
> > self.cache = 0
> >
> > """class TempSensor (Sensor) :
> > def temp (self) :
> > return float (self.sensor.get ("temperature"))
> > """
> > class TempSensor (Sensor) :
> > @property
> > def temp (self) :
> > try:
> > return float (self.sensor.get ("temperature"))
> > except TypeError:
> > print 'something wrong with temp'
> > @property
> > def power (self) :
> > try:
> > return self.sensor.get ("power")
> > except IOError:
> > return -888
> > @property
> > def present (self) :
> > try:
> > return self.sensor.get ("present")
> > except IOError:
> > return -777
> > @property
> > def id (self) :
> > try:
> > return self.sensor.get ("id")
> > except IOError:
> > return "Cant find the id"
> >
> > class Sens1 (TempSensor) :
> > id = "522FA9010800"
> >
> > class Sens2 (TempSensor) :
> > id = "2054A9010800"
> >
> > """ Start of the main program """
> > connection = Connection("/dev/ttyD1")
> > for s in connection.find () :
> > print s
> >
> > loop = 0
> > """ Need to read the sensor list and match the sensors found to the
> > names on the list, mark each one as present or not """
> >
> > s1 = Sens1 (connection)
> > s2 = Sens2 (connection)
> > while loop > -1:
> > print 'Start of loop ', loop
> > print 'S1 reading '
> > print 'temp = ', s1.temp
> > print 'id = ', s1.id
> > print 'present = ', s1.present
> > print 'power = ', s1.power
> > print 'S2 reading '
> > print 'temp = ', s2.temp
> > print 'id = ', s2.id
> > print 'present = ', s2.present
> > print 'power = ', s2.power
> > loop = loop + 1
> >
> >
> > ------------------------------------------------------------------------------
> >
> > _______________________________________________
> > Owfs-developers mailing list
> > Owfs-developers@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/owfs-developers
> >
>
>
>
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>
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> Owfs-developers@lists.sourceforge.net
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