Parsing a serial stream too slowly

[M.Pekala]

On Jan 23, 5:00 pm, Jon Clements <jon... at googlemail.com> wrote:
> On Jan 23, 9:48 pm, "M.Pekala" <mcdpek... at gmail.com> wrote:
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> > Hello, I am having some trouble with a serial stream on a project I am
> > working on. I have an external board that is attached to a set of
> > sensors. The board polls the sensors, filters them, formats the
> > values, and sends the formatted values over a serial bus. The serial
> > stream comes out like $A1234$$B-10$$C987$,  where "$A.*$" is a sensor
> > value, "$B.*$" is a sensor value, "$C.*$" is a sensor value, ect...
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> > When one sensor is running my python script grabs the data just fine,
> > removes the formatting, and throws it into a text control box. However
> > when 3 or more sensors are running, I get output like the following:
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> > Sensor 1: 373
> > Sensor 2: 112$$M-160$G373
> > Sensor 3: 763$$A892$
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> > I am fairly certain this means that my code is running too slow to
> > catch all the '$' markers. Below is the snippet of code I believe is
> > the cause of this problem...
>
> > def OnSerialRead(self, event):
> >         text = event.data
> >         self.sensorabuffer = self.sensorabuffer + text
> >         self.sensorbbuffer = self.sensorbbuffer + text
> >         self.sensorcbuffer = self.sensorcbuffer + text
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> >         if sensoraenable:
> >                 sensorresult = re.search(r'\$A.*\$.*', self.sensorabuffer )
> >                         if sensorresult:
> >                                 s = sensorresult.group(0)
> >                                 s = s[2:-1]
> >                                 if self.sensor_enable_chkbox.GetValue():
> >                                         self.SensorAValue = s
> >                                 self.sensorabuffer = ''
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> >         if sensorbenable:
> >                 sensorresult = re.search(r'\$A.*\$.*', self.sensorbenable)
> >                         if sensorresult:
> >                                 s = sensorresult.group(0)
> >                                 s = s[2:-1]
> >                                 if self.sensor_enable_chkbox.GetValue():
> >                                         self.SensorBValue = s
> >                                 self.sensorbenable= ''
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> >         if sensorcenable:
> >                 sensorresult = re.search(r'\$A.*\$.*', self.sensorcenable)
> >                         if sensorresult:
> >                                 s = sensorresult.group(0)
> >                                 s = s[2:-1]
> >                                 if self.sensor_enable_chkbox.GetValue():
> >                                         self.SensorCValue = s
> >                                 self.sensorcenable= ''
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> >         self.DisplaySensorReadings()
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> > I think that regex is too slow for this operation, but I'm uncertain
> > of another method in python that could be faster. A little help would
> > be appreciated.
>
> You sure that's your code? Your re.search()'s are all the same.

Whoops you are right. the search for the second should be re.search(r'\
$B.*\$.*', self.sensorbbuffer ), for the third re.search(r'\$C.*\$.*',
self.sensorcbuffer )