temperature acquisition on FreeBSD

[Jim King]

patpro wrote:

>>> What I would do today is continue to use the Dallas Semiconductor
>>> temperature probe devices and just drive them from the Dallas
>>> 1-wire to RS-232 serial port adapter.  You'll need some additional
>>> software to discover, address, fetch and convert measurements from
>>> each of the probes as compared to the Spiderplant box.
>>>
>>> As far as software, you can start with /usr/ports/comms/mlan or
>>> /usr/ports/comms/mlan3 to talk to the adapter.
>>
>
>
> If I understand well, you're talking about this device :
>
> https://store.ibutton.com/cgi-bin/ncommerce3/ 
> ProductDisplay?prrfnbr=2531&prmenbr=776


That's the one (DS9097U).


> But it looks like one can only plug 1 probe, and by the way, I can't  
> find simple temp probes.
> The starter kit looks good  
> (http://www.ibutton.com/ibuttons/1921Kit.html) but the DS9097U-S09 
> has  no addressable 1-Wire chip onboard. And it seems it uses TMEX 
> driver,  so I'm not sure mlan or mlan3 freebsd ports can read data 
> from it.


DS9097U is just an adapter to allow you to plug a 1-Wire bus into an 
RS232 port.


> Thermocron looks really good too  
> (https://store.ibutton.com/cgi-bin/ncommerce3/ 
> ProductDisplay?prrfnbr=2438&prmenbr=776) and is apparently supported 
> by  mlan :


Thermochron would be more expensive.  They're $25 each; a plain 
temperature iButton is $7, and bare DS1920s are probably a lot less than 
that.  Also, DalSemi has had major problems producing Thermochrons and 
quantities have been pretty limited for the last couple years.  (A 
Thermochron is a nifty toy to have though - I've had fun with mine.)


> So now, will TMEX driven hardware work on FreeBSD with mlan ? and 
> does  anybody have experience pluging more than one temp. probe on 
> the  DS9097U adapter family ?


The DalSemi 1-Wire bus is really a bus - if you want more devices you 
just wire them onto the bus (i.e. connect them in parallel with the 
other devices).

fyi, I played with mlan3 a little bit.  I connected one of the DS1920 
probes from my Spiderplant HLT into a DS9097U, and the 'temp' program 
from mlan3 worked fine and was able to display temperature readings from 
the probe.

Jim