[Weather] NSLU2 (SLUG) and the 1wire Weather Stations (David Bray)

[David W. Bray]

I have been running a 1-Wire weather station on a Linux PC for several 
years. This summer I converted it to a NSLU2 running Unslung 6.8.
It is running the same source as the Linux PC, just recompiled on the 
SLUG with a few directory/file name changes.

My setup is as follows:
1) I have a 512MB USB flash stick as the only drive, and 1 USB to RS232 
port.  I still have 70MB free on the stick.
2) I set up a ramdisk for the weather station -- both program and data 
storage.  So there is minimal use of the USB flash.
3) The program collects the data and stores it in the ramdisk (shared 
memory) for all applications that want it.
4) Another application runs via crontab every 1/2 hour to send required 
data to two different websites -- Wunderground and my own.
5) Also when the data is sent to the web sites it writes a log file to 
normal flash stick storage. So if power is lost the log is safe.
6) I installed appWeb (web server) on NSLU2 and have a php web 
application to display the data upon demand. It uses the share memory 
data to draw graphs etc.
7) Another php application which will create a WAP html page upon demand 
from my cell phone.

All of the 1-Wire sensors that I have for the weather station are on the 
one 1-Wire line.  I have a second set of 1-Wire sensors that are 
currently read by a TINI. Some time in the future I will put these on a 
NSLU2. If the NSLU2 Unslung will support 2 USB to RS232 ports (which I 
hope can be done with a USB HUB) I will write another application to 
replace the TINI, and it will run independently as a background process 
  concurrently with the current weather station process.  This will be 
nice since then all of my 1-Wire data will be shared on the same device 
in the same shared memory.

The SLUG with Unslung Linux is a wonderful, little, quite, low power 
consumption computer for 1-Wire applications!!!

So my vote for Push or Pull is neither!  Just use the SLUG.

--David Bray

weather-request at buoy.com wrote:
> Date: Thu, 5 Oct 2006 17:56:48 -0400
> From: "Paul Davis" <pdavis at mrv.com>
> Subject: [Weather] NSLU2 (SLUG), OWFS vs OWHTTPD, owwnogui,	and the
> 	1wire Weather Stations
> To: "List for 1 Wire Weather Stations and devices" <weather at buoy.com>
> Message-ID:
> 	<81EF3F1352B56B4A8C6CD53DBC06F3BF9F67FC at bosmail.BOS.int.mrv.com>
> Content-Type: text/plain;	charset="us-ascii"
> 
> I'm soliciting input from others on the list that have been using the
> LinkSys NSLU2 (SLUG) for 1wire operations.
> 
> I've finally got my SLUG operational (unslung 6.8) and de-underclocked.
> Now I'm mulling over different ideas on how to pull the weather station
> (and other 1wire) data from my SLUG and do something useful with it. I'm
> wondering if anyone else is using the owfs/owhttpd approach, or if you
> are all using owwnogui. I'd be interested in the reasoning for your
> decisions regarding one vs. the other.
> 
> In my case, I have more devices to monitor than just the weather station
> and associated sensors, so I opted for owfs. I still have to determine
> whether it's better read the values from owfs and push the data out to a
> data collection/processing server OR to pull the data from the SLUG
> remotely via owhttpd.
> 
> My aim is to have the SLUG be a low power data collection system for the
> 1wire sensors and I'm not doing any local data storage. It's running off
> a 1GB usb stick, so I do have room for other programs, web pages, etc.
> but I do not want to use it for storing 1wire data. The 1wire network
> consists of various branches connected through a single hub and then to
> the USB 1wire adapter on the SLUG.
> 
> So what do you guys think? Push or pull?
> 
> Paul

-- 
David W. Bray
E-mail: dbray at twcny.rr.com
Home Pages: http://davidbray.org