Re: 1-Wire Headache

["marcrfuller" <groups@xxxxxxxxxxxxxxxxxx>]

Hey Martin,

This is how they are wired


VDD ---------- SENSOR1 PIN1 ---------- SENSOR2 PIN1 ---------- SENSOR3
PIN1

DQ ---------- SENSOR1 PIN2 ---------- SENSOR2 PIN2 ---------- SENSOR3 PIN2

GND ---------- SENSOR1 PIN3 ---------- SENSOR2 PIN3 ---------- SENSOR3
PIN3


And this is working fine for the first two sensors, but the last is
still reporting 85c.

I hope the diagram makes it through :D

Cheers

Marc


-- In ukha_d@xxxxxxx, "Martin McCreesh" <martin@...> wrote:
>
> 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
>   >>
>   >>
>   >>
>   >>
>   >>
>   >>
>   >
>   >
>   >
>   >
>   >
>   >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>