Re: [9fans] Twente '9con -- some photos

[Axel Belinfante <Axel.Belinfante@cs.utwente.nl>]

> I'll bet cooling isn't a problem on this device, then... ;-)

right. :-)

on the device under discussion there is another device:
a grey box hidden behind the oven -- you can only see the
cables leading to it on e.g.
http://www.insultant.net/nl/2004/Twente9con/DSC00582.jpg.
The grey box is linked to the plan 9 system via a parellel port.

The grey box houses a webcam (currently not connected,
 it was used until we switched to non-transparent coffee pots)
and some electronics that has the parallel port connection.

The big photo behind the sofa under the world map, e.g. in
http://www.insultant.net/nl/2004/Twente9con/DSC00585.JPG
http://www.cs.utwente.nl/~belinfan/Twente9con2004/Large0/0020.jpg
shows the insides of the grey box, and some of the people
responsible for its existence (student doing the work, supervisors).

A coffee maker receives its power via this grey box.
The electronics can measure the power consumption
of the coffee maker in some rough steps:
 - 0 watt (machine off)
 - 100 watt (keep coffee warm)
 - 2000 watt (prepare coffee)
This info is made available over the parallel port.
The electronics can also cut the power to the coffee maker
if the right command is send to the parallel port.
(to switch the coffee maker off if it has been on too long)

There is a daemon on the plan 9 machine that looks at
the parallel port and polls for the coffee maker status,
and makes it available in a small fs.

The red bar at the bottom of the screen in
http://www.insultant.net/nl/2004/Twente9con/DSC00581.JPG
is based on stats(1), it shows when coffee was being prepared.
It uses the parellport watching fs.

The info used to be made available via the web
and via some client programs on the users' desktops
but is currently not completely operational.
Older info is at http://wwwhome.cs.utwente.nl/~slurp/


The system was developed under linux. When the system (disk)
broke, a while ago, I set it up again, and moved it to plan 9 -
it was a good pretext to get a plan 9 machine up and running
as 'hobby project'. By the time I was ready to tackle (port to plan 9)
the simple image processing software that took the webcam
picture and looked in it for evidence of 100%, 75%, 50%, 25%,
10% of coffee, or no coffee, or no pot, the coffee maker was
replaced by one that uses non-transparent coffee pots
(and no longer has the small heater to keep coffee warm).
A bit later I upgraded the hardware, and the 'new' machine
no longer has the two parallel ports needed to connect
both quickcam and power consumption measuring hardware,
so the quickcam is not used currently.


Axel.

> On Mon, 03 Jan 2005 09:46:41 +0100, Devon H. O'Dell
> <dodell@sitetronics.com> wrote:
> > Dan Cross wrote:
> > > Joseph Stewart <joseph.stewart@gmail.com> writes:
> > >
> > >>Thanks for the photos... I was wondering; in the photo DSC00582.JPG,
> > >>is the device the gentleman has his coffee cup on, is that some new
> > >>hardware Plan9 has been ported to? I'd sure like to hear some detail
> > >>on this!
> > >
> > >
> > > I don't know, but I'm pretty sure it's called a `table.'  I don't think
> > > it'll run Plan 9.  :-)
> > >
> > >       - Dan C.
> > 
> > I'm pretty sure it was a refrigerator, actually... ;)