Kegbot FAQ

From KegbotWiki

Jump to: navigation, search

Contents

What is the software?

There's 3 components to the kegbot software.

  • Micrcontroller Software -- This is a small program loaded on to the microcontroller. It responds to commands over a serial connection, and reports status on the same line.
  • Host controller software -- Several python modules written to talk to the microcontroller, database (of users, privileges, drinks), and interfaces to the LCD and iButton reader.
  • Front end -- A set of PHP scripts that interprets the drink histories and builds the front page (see kegbot.org)


Where is the parts list?

See the Kegboard page for details on the electronic parts.


Is the software available?

Yes! Point your Subversion client at the following URLs: 

http//svn.hoho.com/svn/mjw/trunk/pykeg
http//svn.hoho.com/svn/mjw/trunk/kegbotweb
http//svn.hoho.com/svn/mjw/trunk/pylcdui

Description of components:

pykeg 
Core code that controlls the attached hardware, logs drinks, manages access control, and so on. The microcontroller code also happens to live here.
kegbotweb 
The front-end code; what you see at kegbot.org
pylcdui 
A comprehensive library for controlling CrytalFontx and Matrix-Orbital character LED displays; it includes a library of high-level UI widgets for those displays

All source code is copyright Mike Wakerly 2003-2006, and is released under the GNU General Public License (GPL) Version 2.

Is it secure?

No one has stolen kegbot!


No, it really isn't secure! I can short the valve!

Yes, there are a number of ways one could get around the physical security of the kegbot, including:

  • Short out the solenoid valve relay
  • Lift open the chest freezer, cut beer line, guzzle
  • Build a circuit that pretends to be the iButton for user id X
  • Compromise the controlling PC, inject unauthorized access/cost rules

Let's be perfectly clear here: Kegbot is not designed for total beer security; it's designed with circumventable protection from unauthorized pours -- but by definition, you'd have to be a real jerk to try to circumvent any of these. And do you want a real jerk drinking your beer?

I believe kegbot still provides adequate security for the party scenario: where you very likely will have jerks on your premesis. That said, you're free to design countermeasures for the above scenarios on your kegbot.

--Mike 23:28, 2 Aug 2005 (EDT)


Is it safe?

We are proud to report a 100% survivabilty rate!


Is foam a problem?

Foam has not proven to be a major problem, though due to various technical issues, we can't say 100% that the inline flowmeter and solenoid don't affect foaming.

We have seen slightly elevated amounts of foam in some kegs, but during the development and testing phase of kegbot we have perpetrated many crimes against beer that leave us as yet unable to confirm the source of the foam.

Some things that have contributed to foam in the past:

  • freezing/thawing a keg
  • brass plumbing fittings
  • multiple diameter changes in the beer line
  • cycling the solenoid unduly without actually pouring any beer

All of these were issues during the shakedown of kegbot that have been resolved. We are currently awaiting a few last parts/changes before getting a new keg and thereby new information on this front, but rest assured that despite all of our mistakes the beer was always still drinkable (though occasionally not in the way the brewer intended).

It also helps to make sure your beer line is balanced. Here are two sites on how to balance your beer lines:

Why not use a scale to weigh the keg?

I've heard people mention this idea before, and I don't think its that great. The idea is that, you place a large, sensitive scale inside the fridge, and monitor the decrease in weight as a beer is poured.

I can't imagine this would be more precise or cost less than the flowmeter solution. Unless you found the perfect scale, it would either be too sensitive, or not sensitive enough. I'd be happy to be proven wrong, though. This solution is, however, non-invasive. I'd switch to a scale in a second if it could get ounce-level precision of the flowmeter -- less crap in your beerline, the better!

How much would it cost to build?

Depending on which of the pour monitoring, control, and fridge control components, the cost is probably around $150 for all three. This assumes you have a spare computer lying around.


Why not do everything on a microcontroller?

The kegbot uses a Linux box to store drink data, talk to the controller board, and do other things. Some people might prefer to have the microcontroller board do everything, eliminating the need for the host box.

There's nothing really wrong with this idea; in my case, I just don't have the time and expertise to build an embedded device that does everything I want the kegbot to do. The combination of a specialized controller (with limited functionality) and a host PC to do the rest seems to be working well.


I heard you said Kegbot promotes 'responsible drinking'. What were you thinking?!

Yes, this was the tragically misinformed theme of a Slashdot article on Kegbot. My remark was intended as a joke; I don't believe Kegbot actively promotes responsible drinking, and I don't believe it promotes irresponsible drinking either. Ultimately, how you use a kegbot -- and a kegerator, no less -- is a personal matter.

--Mike 23:28, 2 Aug 2005 (EDT)


I heard you said Kegbot was going to 'revolutionize' drinking games. You're nuts!

There's a lot you could do with a network attached keg, and some sort of kegbot-aware drinking game was one half-baked idea I've wondered aloud about. There's nothing implemented and nothing planned here.

--Mike 23:28, 2 Aug 2005 (EDT)


When kegbot ranks drinkers, how does it know that the person really drank what was recorded?

It doesn't. You'll have to live with some form of the honor system. Depending on your setup, what you charge for beer (if anything) might discourage unnecessary/excessive pouring.

--Mike 23:28, 2 Aug 2005 (EDT)


Can I make a soda-based Kegbot?

Sure; if you are underage or don't like beer, the kegbot would work with many other liquids. Probably some of the fun of the statistics would be lost, however. (See the newly created Soda-based kegbot page.)

--Mike 23:37, 2 Aug 2005 (EDT)

What kind of beer can I put in the Kegbot?

Probably any kind you want. Note that some beers may react differently to the presence of the flow hardware. We've had the following beers on tap:

Yes, Budwiser, Coors, and Miller are not used, as they are thought to be extremely corrosive to the sensitive beer hardware...

--Mike 23:46, 2 Aug 2005 (EDT)

== Where's the !*

Retrieved from "http://kegbot.org/wiki/Kegbot_FAQ"
Personal tools