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Groups > comp.arch.embedded > #13027
| From | Grant Edwards <invalid@invalid.invalid> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Simple protocol analyzer? |
| Date | 2013-08-07 15:02 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <kttni9$e1e$1@reader1.panix.com> (permalink) |
| References | <vradnSIUxLKwt5zPnZ2dnUVZ5qudnZ2d@giganews.com> <ktrb3v$ih6$1@reader1.panix.com> <y_ydnU1gndpIpJzPnZ2dnUVZ5h2dnZ2d@giganews.com> <ktrge0$hrt$1@reader1.panix.com> <xgrMt.1627$7K3.791@fx07.iad> |
On 2013-08-07, Clifford Heath <no.spam@please.net> wrote:
> On 07/08/13 04:48, Grant Edwards wrote:
>> If you want the timestamp for the start of the line, it's a bit more
>> complicated:
>> #!/usr/bin/python
>> import serial,time
>> p = serial.Serial('/dev/ttyS1', 9600)
>> while 1:
>> first = p.read(1)
>> stamp = time.time()
>> rest = p.readline()
>> print stamp, first+rest
>
> Does Python's serial object put the line into raw mode so you can get
> the first character before the linefeed is sent? or did you miss that?
> Just curious, not nit-picking.
Yes. The port defaults to raw mode (8,none,1). The author of
pyserial is an embedded systems developer who (I believe) wrote it to
support a set of tools used for downloading/testing/debugging
microcontroller-based widgets that had serial ports. Since that's
mainly what I use it for, I find pyserial pretty much always defaults
to doing the "right" thing.
What it doesn't do is deal with the UARTs RX FIFO threshold setting or
the Linux tty layer's low_latency flag. If you're using a UART with a
large FIFO (e.g. 128 bytes), the incoming lines of text are short,
don't have significant gaps between them, and you care about
millisecond accuracy, then you'll need to go to some extra work to
select a low rx FIFO threshold and set the low-latency flag on the
device using something like the setserial utility (or the underlying
ioctl() call that it uses).
--
Grant Edwards grant.b.edwards Yow! DIDI ... is that a
at MARTIAN name, or, are we
gmail.com in ISRAEL?
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Simple protocol analyzer? Tim Wescott <tim@seemywebsite.really> - 2013-08-06 11:54 -0500
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-06 17:17 +0000
Re: Simple protocol analyzer? Tim Wescott <tim@seemywebsite.really> - 2013-08-06 13:00 -0500
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-06 18:48 +0000
Re: Simple protocol analyzer? Tim Wescott <tim@seemywebsite.really> - 2013-08-06 14:33 -0500
Re: Simple protocol analyzer? Frank Buss <fb@frank-buss.de> - 2013-08-07 14:52 +0200
Re: Simple protocol analyzer? Les Cargill <lcargill99@comcast.com> - 2013-08-07 08:06 -0500
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-07 14:48 +0000
Re: Simple protocol analyzer? rickman <gnuarm@gmail.com> - 2013-08-07 23:25 -0400
Re: Simple protocol analyzer? John Devereux <john@devereux.me.uk> - 2013-08-08 08:44 +0100
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-08 12:57 +0000
Re: Simple protocol analyzer? Clifford Heath <no.spam@please.net> - 2013-08-07 22:42 +1000
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-07 15:02 +0000
Re: Simple protocol analyzer? Grant Edwards <invalid@invalid.invalid> - 2013-08-07 15:15 +0000
Re: Simple protocol analyzer? Clifford Heath <no.spam@please.net> - 2013-08-08 08:50 +1000
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