Author Archives: benfranske - Page 5

Protecting your Dallas 1-wire network

I’ve written before about the various interesting applications for the Dallas 1-wire network such as HVAC control, access control, weather stations, etc. A few weeks ago I finally got around to ordering some 1-wire sensors to play with myself. I must say that I’ve had nothing but a good time with them. I’m currently running outdoor temperature and rainfall logging which you can see for yourself as the data is uploaded to a number of servers including Weather Underground and the National Weather Service (through the Citizen Weather Observer Program). In future postings I hope to discuss a bit more about how simple this was to get going and show off my own weather homepage (still in development).

For now I wanted to share the design for a 1-wire surge suppressor. As it turns out some people have had a problem, specifically with 1-wire weather equipment, with lightning inducting large currents into their 1-wire network and damaging the sensors and/or serial adapter. To combat this problem Philip Gladstone has posted some easy to build protection circuits for both 1-wire devices and the serial port adapter. While I haven’t built them myself yet I hope to have some time to do so before storm season gets into full swing.

Thoughts on the Virginia Tech tragedy

I have a fe thoughts on the tragedy that occurred yesterday at Virginia Tech that might provide interesting points for discussion. As our understanding of the situation continues to unfold there will undoubtedly be more calls on the administration at VT to provide answers. For example, there are already a great number of media outlets wondering about the use of email as a notification mechanism as well as the decision to hold of notifying students and canceling classes. Some of the criticisms will be fair and deserve to be heard but many are just the media pandering to those who have little connection to the education system and minimal understanding of the situations faced by school administrators and faculty. Here I will lay out a few of the questions being asked and provide information about why or why not they may be appropriate criticisms.

First, I remain amazed at how such a great number of people will instantly seize the opportunity to use a tragedy such as this to push an agenda which may not even have much to do with the event at hand. So far today I’ve already heard from anti violence in media and games groups blaming video games and a culture of violence for acts such as this. While it may or may not be true to any variety of degrees it seems rather early to be pushing this agenda with the little we know about the impetus for the attack. These groups would certainly have egg on their face if the assailant turned out to be a Luddite who turned out to avoid all media, this is unlikely by my point stands that it’s simply too early to be saying anything like this. I’ve also heard from both sides of the gun control issue saying that either there are too many guns which enables this kind of attack and conversely that if more people had guns it would have been stopped earlier. While I personally believe the second amendment has it’s uses (particularly in the original intent of overthrowing an oppressive government) and have no significant issues with sport hunting I think it is overused to justify things such as conceal and carry weapons. I do think it’s rather silly, naive and agenda pushing to think that if everyone were carrying a weapon this kind of attack could either be dissuaded to begin with or quickly contained. It’s easy to get facts about gun control but much more difficult to get meaningful contextualized and realistic ones. My own feeling is that a great number of people carrying guns are ill prepared to use them and are likely to make a situation worse rather than better. On the other hand let’s be realistic gun control would not prevent violent crimes such as this, laws are easily ignored and bypassed. What gun control is really about is stopping people from committing crimes of passion, someone who upsets someone who just happens to be carrying an easily accessible gun and decides to use it in the heat of an argument. But enough on that rats nest.

Secondly, I think one of the most difficult things for the VT leadership to deal with, at least from a PR perspective, will be the question of student notification and the delay in the decision to cancel classes. As far as the method of notification goes there has been a lot of talk about the use of email by the media and whether this is appropriate. My response is that it is most likely the only way to reach as many students as possible in a short amount of time. Unlike a K-12 school where students are typically confined to a single or small cluster of buildings college students are widely spread out at any given time and I know of no college or university with a site wide paging or notification system so the only alternatives to email I can think of would be broadcast media (which was most likely already reporting the incident) and driving police cars around using their PA to address students though this is only a realistic way to reach people outdoors and not those in buildings. As for the delay in official notification, there is a legitimate question about why it took so long but it’s not unusual in college scenarios. Most college administrations tend to avoid sharing details about much at all with students or anyone else until their hand is forced. It seems to be an unfortunate culture which has developed because they want to avoid riling up students over the many unpopular decisions they make. Here I do see room for criticizing the administration but it’s unlikely we’ll see wide scale change of this behavior of withholding information from students on a broad scale because it is so deeply ingrained into the administrative structure.

Finally, there is the issue of the delay in canceling classes. This is really a different issue than notification as it could occur before or after notification and independently of any other notification. Again, the decision to hold off canceling classes until quite a while after the first shooting is a legitimate place to criticize the administration and is similarly ingrained within the educational culture. For several reasons, some to do with academic freedom and others to do with logistics and the history of continuing classes through many situations, administrations in general tend to shy away from canceling classes college wide in favor of leaving it to individual instructors many of whom share similar beliefs that the “show must go on”. For example, the University of Minnesota prides itself that it cancels classes university wide on very rare occasions and there was much discussion about a closing this winter for one day due to weather. On a more related note when I was doing my undergraduate in Wisconsin we actually never canceled class on September 11, 2001 and I continued to attend classes all day knowing full well the state of terror found throughout the country that day. Many professors fully expected students to continue to come to class and have regular discussions despite the events of the day. Not until the next day did the University cancel classes as a day of mourning and reflection. This seems to be rather typical in the college and university environment and something that may indeed be changed by this incident.

I would not at all be surprised to hear that VT will be sued by the parents of victims, especially those from the second attack, who feel the university was negligent in not canceling classes and warning students. I would not be surprised if the parents would prevail either. Barring significant evidence from the school that they acted reasonably I think most juries would be inclined to hang them out to dry. Again, I think there is a legitimate complaint that they failed to make decisions that could have prevented a great number of the deaths and I think they will have a hard time convincing people otherwise.

The problem of multicasting

Bob Cringely has an interesting article about a new service called NeoKast which purports to make internet video broadcasting possible without requiring multicast support at the router or substantial amounts of bandwidth. I’m sure the technology is patented, which is unfortuanate as it would be nice to see some open versions of this software. As far as I can tell the NeoKast service is essentially emulating a multicast network by using peer hosts to spread the feed, in real time, to other viewers in a peer to peer manner. It’s an interesting idea but perhaps its time has already come and gone. While there are some live events that attract enough viewer interest where considerable amounts of bandwidth might be saved, for the most part it seems that the future of Internet video is on demand video which is a horse of a different color and which does not benefit from this method at all, at least in its current incarnation.

Online Amateur Radio Repeater Directory

I recently found the website which contains a listing of many of the amateur radio repeaters in the United States. I actually had a plan at one point to develop a similar PHP/MySQL driven site but simply have way too many other projects going to take on another. That said I do have a few issues with the US Repaters site. First, the site is a mess graphically and navigation leaves a lot ot be desired. The lack of an interface for owners of repaters and/or coordination bodies to make changes, users to search, etc. is also unfortuante. Secondly, the data is copyright instead of being open and freely available. As inexpensive as webhosting is these days and seeing that ham radio has a long tradition of sharing knowledge I am disappointed to see someone attempting to assert control over this factual data. I think a simple ad supported site (not the ads all over approach US Repeaters takes) would be sufficient to support such a directory. If someone out there is interested in working on an open PHP/MySQL repeater directory I would be more than happy to provide web space, bandwidth and my ideas. Contact me if interested.

Converting PAL DVDs to NTSC

Occasionally I’ll find a PAL (European video standard) video which I really want to preserve on an NTSC (US/Japan video standard) video DVD for showing where computers are not at hand. Because the frame rate of the video (the number of still pictures in each second of video) differs but sound must remain synced up this is a difficult thing to do. One of the best sites I’ve found with instructions for doing this with free tools is this one. The downside is that it’s a pretty lengthy and involved process and, at least to my eye, the end result is still sub-optimal. If you have any better resources for making this conversion I encourage you to post a comment and share them.

Remembering Chernobyl

On April 26, 1986 reactor 4 at the Chernobyl nuclear power plant in the Soviet Union near what is now Pripyat, Ukraine. Nearly twenty one years later this remains the worst nuclear power accidents and a reminder of both the awesome and potential destructive nature of nuclear power. In recent years, as radioactivity levels in the area have decreased and time has marched on, there has been much less discussion about the accident and it often receives only a cursory discussion in schools. To those still living in the area who see constant reminders of the destruction and sacrifice which followed the accident the Internet has provided a medium to ensure the accident is never forgotten.

In many ways the Chernobyl accident remains shrouded in mystery. In part thanks to the suppression of news and reporting during the Soveit era and in part due to the deaths of key figures there remains much we do not know about the accident and the aftermath. In much the same way there is controversy surrounding the discussion of the accident as well as modern exploration of the accident site. The goal of this article is to provide some guidance in the exploration of Chernobyl related resources.

A good place to start for an overview is the Wikipedia article on the Chernobyl disaster but remember that Wikipedia can be edited by anyone and may contain bias or inaccuracies. Another good place for background information and papers is the International Atomic Energy Agency’s Chernobyl page. If you’re specifically interested in the natural implications of the disaster you may want to check out the book Wormwood Forest: A natural history of Chernobyl by Mary Mycio.

Once you have a good understanding of the disaster itself you may want to start looking at some of the modern exploration and notes from the Chernobyl site. One of the most popular sites was created by the so called “Kid of Speed” Filatova Elena Vladimirovna who wrote two photographic stories (Ghost Town and Land of the Wolves) of trips into the exclusion zone and hosts them along with other thoughts on the disaster at her website. It is worth noting that several people have called parts of her stories (particularly early revisions) out as hoaxes but she remains a prominent figure and committed to remembering the disaster and her site contains many interesting photographs from the so-called exclusion area. The Nuclear Flower site, an anti-nuclear power site from Australia, contains some higher resolution photos from the exclusion area. The 26-04-1986 site was setup by seven artists from Moscow, Minsk and Berlin to commemorate the twentieth anniversary of the Chernobyl disaster and contains some artistic photos from the area. National Geographic also featured the Chernobyl disaster in their April 2006 issue and this online exhibit. Use the links of the side of that page to see photos, writings, maps, sites and sounds from the area. Looking toward the future you may examine the site, setup by the Swiss Agency for Development and Cooperation, which bills itself as an “international communications platform on the longterm consequences of the Chernobyl disaster”.

Downloading online Flash video

As with many technologies, the advent on online Flash video (flv) has both an upside an downside. On one hand it eliminates, or at least substantially reduces, the need to have a great variety of platform dependant streaming video tools (a la RealPlayer) but on the other hand there’s a lot of good, or at least interesting, content on YouTube which could either disappear without notice and requires an Internet connection to view. This is an argument I have with most of these Internet based services such as YouTube, Flickr, etc. I think people are setting themselves up for a future problem by posting so much potentially important data at sites with unknown and uncontrollable futures. Enough of my rant though. The point here is to find a solution, or at least a mitigation strategy for viewing Flash videos offline.

Thanks in part to others experiencing the same problem and the popularity of YouTube there are a number of people with an interest in this. Several online sites such as KeepVid and Javimoya offer web-based methods of saving these videos as well as downloadable FLV players for viewing them. Again though, I have a problem with relying on web services which are unpredictable in the future. A better solution would be to use a cross platform script, such as the python based youtube-dl, which does not rely on the cooperation of a third party. Even better is to understand how a script such as youtube-dl works by reading some information on manual FLV downloading from sites like this or this.

Remebering toasters that fly

I was recently reading some excellent interviews Tommy Thomas, of Low End Mac, did with the AfterDark team which brought back some fond memories of the flying toasters. Those who remember the quirky early Macintosh screensaver developed by After Dark (later Berkely Software) often wonder where the creativity went in screen saver development, something Thomas touches on in his interviews.

For the time being those who wish to relive the golden days of the screen saver you’ll either need to find an old copy of these screensavers many of which don’t run on modern operating systems or check out some of the knock off versions such as this free one, which unforunatly doesn’t look much like the original.

Decoding MDC Data

Many towns, counties and states still using analog based radio communications systems for public safety use Motorola MDC systems which emit a short “chirp” at the beginning or end of a radio transmission. If this is the case in your area you might be interested in the open source WinMDCD software. This software allows you to decode that chirp with a Windows based PC and see data such as date, time, unit ID or whatever else they’re transmitting. Note that if you’re interested in Motorola radio technology a great resource is BatLabs, in particular the BatBoard which has a great number of people who are extremely knowledgeable about Motorola radios.

I only wish I could have a room like this

Someone recently shared a link to this flickr collection where someone is showing off their basement Macintosh collection. I too have a basement vintage Macintosh collection but mine resides mostly on shelves and only gets pulled out for special occasions. I only wish that I had room and time to create as neat a display as this person has.