Re: [misterhouse-users] Dallas onewire help, please

[Neil C. <nc...@co...>]

Denis Cheong wrote:
> Neil Cherry wrote:
> 
> 
>>OK, I've found further information, seems that the ports and onewire
>>devices are working. I checked them with an external program and
>>I can poll the temperature probes. Since others have said they have it
>>working I'd like to know what kind of serial port do you have it working
>>with and what DS9097xxxx are you using? Further testing to follow.
> 
> 
> Neil
> 
> I have my 1-wire network sort of working with the DS9097U-009, and have had
> 2 DS18B20 (temp sensors) and 3 DS2407(6)s (TO-92 package) connected via a
> Digiboard Classic PCI 8-port serial interface.  I also have a number of ID
> buttons.

I've not had luck with the Digiboard (a different problem). I'll be working on
that later.

> At the moment my problem is that the relays on the DS2407s don't seem to
> like staying on; they reset themselves without rhyme or reason after a few
> seconds, half an hour, a few hours ... I think it's a bus power issue, in
> that (according to the data sheets) if the data line is held low longer than
> 5ms while the DS2407 is in an "on" state the DS2407 will  reset its memory
> and revert to off ... I'm still working on resolving it :(

Try moving the DS9097U over to a plain serial port and see if the problem
persits. I know that the Digiboard Xe had limited power output. My DI-194
refused to work on it but it worked on the normal serial port.

> In my experience, the DS9097 has some funny circuitry in it, in that if you
> reverse the polarity of the 1-wire or do something else even more stupid it
> will lock up to protect itself, in proportion to how stupid what you were
> doing was.  So if you reverse the 1-wire polarity for a few seconds it will
> stop reporting anything for a minute or two, and if you stick it with 12V
> from your power rail, then it will lock itself up for a few hours.  Leave it
> overnight and it comes back good and true.  Strange...

Last night I did some further testing. It turns out that I can't use the
older DS9097 (bit twiddles DTR, and RTS). The DS9097U-009 has an extra
chip that I guess is needed so I've ordered 2 of them. The onewire stuff
works with an external program made for the DS9097U-S09. So I'm guessing
that is what is causing my problems. Still more to follow.

-- 
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