> Date: Thu, 30 Apr 2015 08:28:23 -0400
> From: Paul W Panish
> Subject: Re: [Owfs-developers] Temperature sensitive bus timing using
> DS18B20
> I'm running Debian Linux on a Beaglebone Black. I've done nothing
> special for a kernel build, and I've built owfs u
Am 30.04.2015 um 14:28 schrieb Paul W Panish:
>
> I have some questions on your comments. The issue of the w1 drivers
> is new to me, and sounds like it may be an explanation of what I'm
> seeing, though I still don't understand why there should be a
> temperature dependence.
>
I don't see any co
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Jan,
I have some questions on your comments. The issue of the w1 drivers is
new to me, and sounds like it may be an explanation of what I'm seeing,
though I still don't understand why there should be a temperature
dependence.
I'm running Debian Lin
Actually the Hobbyboards product I was talking about is the DS2408 based
Parallel I/O board. As I just said, I'm also using the LinkUSB bus master.
Paul W Panish
Mobile: (603) 343-8901
> On Apr 29, 2015, at 22:40, Eloy Paris wrote:
>
> Hi Loren,
>
> On Wed, Apr 29, 2015 at 06:03:56PM -0700,
> owfs-developers-requ...@lists.sourceforge.net wrote:
> From: Paul W Panish
> Subject: [Owfs-developers] Temperature sensitive bus timing using DS18B20
>
>> My problem is that there seems to be a strong temperature dependency for
>> bus read/write errors caused by the DS18B20 sensors.
Mick,
I don't know anything about the Python api, or how it returns errors. I'm
pretty sure owfs performs retries under the hood, but I assume these are
invisible to the user. I'm not doing anything more than checking for error
returns from OW_get() in the c api. It sounds like you're already c
Hi Loren,
On Wed, Apr 29, 2015 at 06:03:56PM -0700, Loren Amelang wrote:
[...]
> So I'm watching for ideas on which USB interface to try...
> Hobbyboards seems to be well recommended, but this kind of report
> makes me worry. Are you using their USB interface to reach your
> 18B20s? I guess
On Wednesday, April 29, 2015 at 12:06 PM,
owfs-developers-requ...@lists.sourceforge.net wrote:
From: Paul W Panish
Subject: [Owfs-developers] Temperature sensitive bus timing using DS18B20
> My problem is that there seems to be a strong temperature dependency for
> bus read/write errors
Hi Paul,
I use Python to drive my system, at startup and every hour I walk the
1-wire directory looking for devices, all other times I just use read().
This is all in a try: except: and exceptions are written to a log file,
but that gets rotated. I have looked in the current logs and there are
Am 29.04.2015 um 18:35 schrieb Paul W Panish:
>
> Thanks for that, I'll implement the verification on write, I didn't
> realize that I could read from the output register without affecting
> state. This may be enough to get the levels of reliability I need.
>
Actually, the DS2408 PIO write comman
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Jan,
Thanks for that, I'll implement the verification on write, I didn't
realize that I could read from the output register without affecting
state. This may be enough to get the levels of reliability I need.
Note that the only element in the syste
Am 29.04.2015 um 02:04 schrieb Paul W Panish:
> I’m providing power and
> ground through the CAT5e cabling.
>
I assume you use one wire for +5V, one wire for 1W and six wires for
GND? That would be correct.
>
> The errors are not just on access to the temperature sensors (which are
> hot), but
Rick,
That sounds unrelated. Most likely you have an intermittent short or
broken wire (if normally closed, perhaps caused by temperature), or your
door contact is causing a similar problem.
My problem isn't with bouncing inputs, it's that the device access is
corrupted at high temperatures.
Pau
As an aside, I too use a Hobbyboards 8 Channel I/O (DS2408) board. At
the moment I use it to sense state of a magnetic door contact. The
hobbyboard is located in an upstairs closet near the home automation
computer that collects data. The wire connecting the magnetic door
contact is thin gauge
Mick,
Thanks for the response. The mechanism I've implemented attempts 5 reads
as quickly as the api responds. As each access fails I log the error
message returned by the api as a WARNING and retry. After 5 attempts I
log an ERROR and skip the update. Unfortunately I mistakenly deleted my
log fil
Hi Paul,
I assume all references to temperatures in your mail are degree F, if so
I am surprised that it causes a problem. I use 27 DS1820's on my system
which includes 7 measuring solar panels, these can and have gone to over
120 degrees C and I have not experienced the problems that you have
I’m wondering if anyone has information on an issue I’ve been having
with DS18B20 temperature sensors.
For some time I’ve been developing a wood fired boiler/heating/DHW
system controller
(https://sourceforge.net/projects/bctl/?source=directory) using the
owcapi for all sensing and I/O functionali
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