Re: 1-Wire Headache

["Martin McCreesh" <martin@xxxxxxxxxxxx>]

How do you mean 'wired in series'. The data lines should all be
connected to the same wire.
----- Original Message -----
From: Quinten Uijldert
To: ukha_d@xxxxxxx
Sent: Tuesday, July 17, 2007 10:14 PM
Subject: Re: [ukha_d] 1-Wire Headache


And another question is if you are using parasite power or not? And
what Dallas sensors they are? DS1820 or DS18S20?

On 17 Jul 2007, at 19:42, Stuart Poulton wrote:

> Marc,
>
> 85c is the reading that is returned as an error, normally that a
> conversion wasn't able to be made.
>
> 2 questions
>
> 1 - Are you making connections to all 3 legs of the sensors ?
> 2 - What sort of cabling are you using.
>
> I've successfully run 1-wire over 100m of cat5, using modules that
> daisy chained (modules of my own design)
>
> Cheers
>
> Stuart
>
> On 17 Jul 2007, at 17:49, Marc Fuller wrote:
>
>> Hey Guys,
>>
>> Just bought myself a TEMP08 to replace my Quasar logger. It's all
>> up and
>> running and 3 of the sensors are working perfectly. My problem is
>> with
>> the fourth.
>>
>> For some reason the fourth sensor that is at the end of the bus,
>> keeps
>> showing a temperature of 85c, which is obviously not correct.
>> Occasionally it will show the correct temperature, but mostly it
>> shows
>> 85c. I replaced the probe with a new one and am getting the same
>> thing !
>>
>> Now I must admit I don't totally understand 1-wire yet.. this is
my
>> first proper jump into it. So it could be that I have set up the
bus
>> incorrectly ? or what else is likely to cause this problem ?
>>
>> The probes are wired in series and the farthest one is only about
10
>> meters away.
>>
>> Anyone got any ideas ? Could I just be really unlucky and have two
>> probes shorting out ?
>>
>> Any help appreciated
>>
>> Marc
>>
>>
>>
>>
>>
>>
>
>
>
>
>
>





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