Author Archives: benfranske - Page 10

Collecting weather with one wire

I thought I’d written about this in the past, but it appears I have not so I’ll have to take a bit more time to explain this than I thought. To make a long story shorter my interest in weather and computers indicates that at some point I would like to have a computerized weather station at the house. In looking into this, and with my strong preference for inexpensive and open source solutions, I came across the Dallas Semiconductor 1-Wire protocol. As it turns out there are a lot of things you can do with the 1-wire protocol, including using their iButtons and readers as the basis for an access control system (another fun project). One of the early ways they popularized the 1-wire system was by developing an inexpensive weather station.

The station is now sold by Automatizacion Aplicada a Gasolineras (AAG) on their website. The sourceforge One Wire Weather (OWW) project is an open source solution to logging and displaying the data from just such a station. As an added benefit the OWW project has a page listing hardware suppliers, projects and scripting resources. If you’re interested in this sort of thing I encourage you to look at the 1-Wire products and the OWW project as a fun activity.

News for campus computing

I don’t know that I can add another publication or website to my list of reading material becasue I’m already so far behind but I found out that there’s an enterprise IT trade paper just for college and university settings. CampusTechnology is a monthly publication with roots going back to 1988 and published by 1105 Media, which is nice to see since the majority of the trade journals are controlled by CMP and IDG.

Shorten that URL

Several times in the past I’ve considered building an open source program similar to TinyURL (with some improvements) for my own use. I think it would be especially handy as a way for me to link to other sites from my blog while keeping strict anti-spam measures in place (which sometimes whine about my own off-site links).

I can’t believe this hasn’t been done before as the code shouldn’t be that difficult. I did spend some time recently looking for starter code but didn’t quite come up with what I was looking for. Instead I found lists of simialr sites which don’t appear to use open source code either the notlong service has links to some of their competitors and the Perl Shorten library gives another list of such services. The closest I have come is this short url php script but I haven’t looked at the code yet and I’m tempted not too because I’m not thrilled with the way the short urls appear to be handled and there is no information about how the code is licensed. The last thing I want is to get caught up in a licensing battle like the SCO/IBM case.

If you know of any open source PHP/mySQL URL shortening projects please add a coment and share the wealth.

Ajax comes to your server

I recently heard about the nifty Ajaxterm project. The idea is to provide terminal access to Linux servers without the need for a Java client which has been the way this has been accomplished in the past. Obviously the connection is insecure unless you use SSH and relies on the local webserver staying up so their are some limitiations. Nonetheless, this is a cool project and one that could prove useful in a number of system management scenarios.

Organizing Books

I have a lot of books, probably far too many and certainly far too many for me to remember what all I have. I often think it would be helpful if I could search a database of my books when I’m checking to see if I have something. There are some sites online where you can do this with a small collection for free or pay to catalog a larger collection but I have two problems with that. First, I don’t like trusting comapnies with my data which could be sut off at any time. Second, I have this thing about doing it myself and using open source software. I keep meaning to write a simple PHP/mySQL program to handle this but just have too many similar PHP/mySQL projects that I need to work on first.

I recently came across some open source software that would provide a good atarting point for such a system. Home Library seems to be just what I’m looking for, though it may be a bit immature. I’m going to be keeping my eye on this as I could use somthing to catalog all my DVDs and videotapes as well. I was also pointed towards the bibliophile project at sourceforge. While not a final product itself they have a number of links to catalog like programs on the projects page. While these are more geared towards organizing references for papers they are useful in their own right and apparently might be useful as catalogging software too.

Recovering from an ext3 hard drive crash

If you run a Linux system and have had the misfortune of having your hard drive crash without a recent backup or RAID configuration you’re in for a world of hurt. Thankfully, there are some free utilities that might make things go a bit easier for you.

My favorite utility is a gem called dd_rescue. This program will work quite hard (and efficiently) to recover as much of your data as possible onto another hard drive or a disk image. It does this by reading smaller and smaller block sizes, isolating as much of the good data as possible before copying it off. Of course this program can’t bring back data that is in the bad area itself, but it does salvage everything it can. I’ve used it a couple of times and one time it worked pretty well, recovering all the important data and the other time I got almost nothing usable. If you need a quick and dirty attempt to get things going again as quickly as possible this is your ticket.

SHSU switches from Cisco Call Manager to Asterisk

According to NetworkWorld Sam Houston State Univeristy in Texas is moving from Cisco Call Manager to Asterisk for the backend of their VoIP system. The story is being discussed on Slashdot as well.

Score one for open source! As someone who has worked on both the Asterisk and Call Manager platforms I have to say that I much prefer working with Asterisk.

Ultra cheap VoIP Phones

If you’re in the market for a very inexpensive VoIP phone you might want to take a look at something based on the PA1688 chipset. You can find a list of manufacturers who sell these phones (for as little as $50 I’m told) on the VoIP-wiki though the page is labeled as PA168 for some legacy reason.

After looking at a few of these phones I would never use one in a commercial installation where my preference would be for a Cisco or Polycom (two of the best) but they would be suitable as something to play around with on Asterisk at home or in a lab.

In related news I also heard about the OpenPBX fork of Asterisk. There is a little bad blood between the Digium and OpenPBX developers, essentially because the forked the Asterisk code because they didn’t want to give up the copyleft portion of the GPL license when contributing code to Asterisk (essentially prohibiting Digium from reselling or relicensing their changes). Something to keep an eye on if you’re interested in Asterisk or open source VoIP.

On Education and School Reform

There’s been some news recently in school reform circles centered around the opening of the Microsoft “School of the Future” in Philadelphia this fall. One such story is this one at the excellent blog and discussion site of John C. Dvorak. There, in the comments, you can already see the debate among the public-at-large about the effectiveness of school reform measures. This is a common and distrubing trend in talks about school reform. The uneducated public has little knowledge about what makes schools work and what doesn’t. What they have is “feelings” and articles from newspapers and magazines that are often incorrect and unreliable. Anyway, I wrote the following response in an attempt to encourage people to research and understand the problem before complaining and making foolish statements. If you’re interested in this sort of thing a must-read is “The Academic Achievement Challenge” by renowned educator Jeanne S. Chall. I don’t agree with a lot of her conclusions in the book, but it’s a great place to start the discussion.

As someone in the middle of an Education PhD program I have a few things to say. I don’t want to get into a long debate about this because I simply don’t have the time. First, I have read some about these Microsoft schools but I’m no expert. That said, the general public (and the politicians that cater to their wants) knows very little about education. There is a lot (and I mean a lot) of research about how students learn best and the best methods for teaching. The problem with implementation is at least twofold.

First, things like interdisciplinary learning work well, very well in fact. Here the implementation problem is generally cost. To do interdisciplinary learning well teachers of different subjects need to meet on a daily basis for a considerable amount of time and have additional planning time to boot. In effect you reduce the amount teachers can actually spend in front of a class by a quarter, meaning you have to hire more teachers and thus spend more. This is not something that makes the public or politicians happy. If you stary cutting corners to try and do it anyway you end up with less than satisfactory results and no one is happy. I always say that education would be the most expensive thing for the government to provide if it was done right. If people knew how much it really cost to educate someone there would probably be calls for the end of public education and a serious debate about whether education is worth it, it costs that much.

Secondly, public perceptions of education are a barrier to improving it. There is not general public (or political) support to take research into the classroom and apply novel teaching methods. In addition to costing more things like interdisciplinary learning, more teamwork and not having to memorize useless facts and instead learning how to research and solve problems are not what the majority of people want taught in schools. Parents generally are unhappy to learn their child no longer needs to memorize massive amounts of information such as dates and names which can be easily looked up. Even in the comments here you’ll find that people will debate what students should memorize vs. not. The effect is that novel teaching methods are usually undermined and not put fully into place making them less effective. The mentality is often that “I learned all this stuff in school, why aren’t my children” without the realization that there has been a paradigm shift in the world and what was appropriate in the past may no longer be appropriate.

My personal opinion is that people are far too open about criticizing education when they have little knowledge about how the education works. If you’re serious about wanting to make a change in education (or anything else for that matter) and want to criticize it you should spend a copious amount of time studying the research and not the junk you see in the newspapers and magazines, I mean real research studies published in refereed journals. If you start wanting to make changes before you understand why things are the way they are you end up wasting a lot of energy and can potentially cause a lot of students to be ill-prepared for their futures.

Recycling Paper

If you’re like me you generate a lot of paper that is printed on one side. Of course, you could put the paper in the recycling when you’re finished with it but assuming it doesn’t have any confidential information you could give it a new life as a scratch pad first.

My personal preference is to cut 8.5×11 sheets into quarters, but some may prefer halfs. The real trick is knowing what you need to glue the sheets together into notepads. While some people use multiple coats of rubber cement my preference is to do it the real way and use what the priniting/binding industry calls “padding adhesive” or padding glue. The trick is to get the edge you’re going to glue lined up straight and either weight down the edge or put it in a clamp such as this which are easily built or bought. You’ll need to apply several coats of padding adhesive with a brush, letting things dry between coats. Once the final coat is dry you can slice apart the large pad into several smaller ones using a common table knife or a “pad knife”. If you want a more professional stiff backed pad be sure to insert thick cardstock in the stack before gluing where you’ll split the pads. You could even go a step futher and use something like cut up macaroni and cheese boxes for the cardstock backing.

You can usually find padding adhesive where printing supplies are sold. Online it is available from a number of vendors for around $10 a quart.