lardbucket: technology


Calcsy – See your calculator on your computer

Filed under: Education, Math, Programming, School, Technology — Andy @ 9:17 pm

Calcsy LogoCalcsy is a tool you can download and use on your computer to show (and save) the screen of your TI-84+ or TI-89 Titanium calculator.

It’s useful for projecting the screen large enough for other people to see, or for taking a screenshot to use in instructions. For example, I’ve used it in teaching how to graph functions on a calculator, and I suspect it will be similarly useful to other people.

I first wrote Calcsy almost two years ago, and have been (very) slowly making it better since then. It’s now to a state where I think it’s reasonable to release. At the moment, it’s only available for Mac OS X, although it should be possible to port to Windows if there’s enough demand. Hopefully it’s pretty self-explanatory, but feel free to let me know if you have any questions.

All you need is a TI-84+ (or TI-84+ Silver Edition) or TI-89 Titanium and a USB cable to plug it in to your computer. The program is free, and you don’t need any special software on your calculator. (You also don’t need one of the special “Presentation Link” adapters – your computer and a normal USB cable works just fine.)

Other details of note: I suspect it won’t work with the very new TI-84+ Color calculators, but I’m happy to try to make it work if someone wants to send me one. Also, the logo was made by David Felice, so thanks are due to him.

Anyway, it’s free, go check it out. Let me know if you have any questions/comments/problems/etc.

Andy Schmitz


Getting Complicated, Embedded YouTube Videos

Filed under: Hacks, School, Technology — Andy @ 3:29 pm

So, earlier today, Karl Fisch asked for a copy of an Olympics video from NBC’s website to use in his school. A number of the “standard” ways of getting the video didn’t seem to work, so I figured I’d pitch in. By the way, the first thing to try (if whatever addons you might have to download YouTube videos don’t work – although I don’t use any myself, I’m told they didn’t work in this case) is to click the YouTube button.

The YouTube button will usually open the video up into YouTube’s website, where most addons for downloading a video will work better, and there are plenty of other websites happy to help you.

In this case, clicking the button only got to the NBC Olympics home on YouTube. A quick search of the channel showed that the video I was looking for wasn’t on the NBC Olympics channel, and I’d have to find another way to download it.



Announcing scavhunt

Filed under: Open Source, Programming, School, Technology — Andy @ 5:48 pm

Since the end of Dan Meyer’s SLV SCAV, it’s been in the back of my mind to get the source code available to more people, and there was at least some interest from others about running their own copies.

As a result, I took the time to go through the code, remove any references to the school, students, or teachers that I could find, and generally cleaned the code up for release. I changed the name to “scavhunt,” and made a working version that I can release. I’m happy to say that the code is now available as open source (AGPL v3), from GitHub as scavhunt.

Unfortunately, I haven’t yet had the time to properly document things. As it is, if you pull the code down (either use git if you’re comfortable with it, or download a tarball/zipball with the “Downloads” button in the upper-right corner of the GitHub page), it should be a working scavenger hunt, although a bit sparse. There are a number of files you should modify, and some directories that need to be writable by the web server, but those are all documented on the file (and also on the GitHub page for the project). It comes with two example questions as a basis for writing your own, although additional question types exist in the code as well.

So, the code is now available for your use, however you see fit (as long as it complies with the AGPL v3, which is pretty relaxed in terms of usage). If anyone has any questions, feel free to contact me at andy [dot] schmitz [at] gmail [dot] com, or potentially file an issue on GitHub (although I’m new to GitHub, so it may take me a while to figure out how to respond). Unfortunately, at the moment, I don’t have enough time to necessarily improve the code in the ways I would like to, but I can certainly answer questions and respond to pull requests from those who would like to improve it on their own. Contributing your improvements back would be greatly appreciated. And hey, if you use it, I’d appreciate an email or tweet (@aschmitz) to see where it’s in use.

Andy Schmitz

P.S. This is indeed where the scoreboard movement tracking code came from, so that section is rather well-commented. Unfortunately, the rest is less documented, but hopefully understandable.


VP8, WebM, and FFmpeg

Filed under: Programming, Technology — Andy @ 8:06 pm

So, today at Google I/O 2010, Google announced that, along with a number of other groups, they were releasing WebM, a video container and codec. (WebM itself specifies the container, which is a variation of Matroska, as well as the video format, the newly-released VP8, and the audio format, Ogg Vorbis.) I won’t get into the technical details of the codec, as I’m not really qualified to do so, but a developer for x264 has a reasonably thorough review of a prerelease version of the code here.

The interesting part of VP8 / WebM is that it is a reasonably good video standard that may be theoretically free to use. (The currently popular “best” video format, H.264, is riddled with patents and requires licensing for most uses, although encoding video that’s available for free doesn’t require payments until at least 20151.) It doesn’t appear as though anybody is claiming that WebM is the best video format available, but it’s reasonably good, and potentially free to use. (It’s impossible to know whether someone else has patented parts of the standard, because that would require examining every software patent ever granted, which is not going to happen.) For some background, the video codec, VP8, was produced by a company named On2 before Google bought them last year. Its predecessors, VP6 and VP7 were used for video in Flash2 and the video in Skype3, respectively.

Most of this will be fairly boring to anyone who normally reads this blog, but if you’re interested in a way to encode WebM videos yourself in Ubuntu, read on.


  1. The press release PDF from MPEG LA, the group licensing the patents for H.264
  2. An Adobe article on encoding video for Flash using VP6. An earlier version of this post claimed VP6 was the original codec for Flash, which is false.
  3. A press release


PvPGN for a Private LAN

Filed under: Hacks, Programming, Technology — Andy @ 10:43 pm

A few notes on setting up PvPGN (the continuation of bnetd) for a private LAN. (The reason I’m setting it up is that I don’t expect to have an Internet connection for connecting to proper, and would like to have the capabilities it provides, especially ladder games.) This post is generally much more technical than most of my previous posts, so you may want to skip it if you’re not really sure what’s going on. You won’t miss much.

So, my setup involves a router with DD-WRT, and an OLPC XO. The XO is set up using Ubuntu Intrepid on an SD card.



GraphSketch: Ten Thousand

Filed under: Ego, Hacks, Programming, Technology — Andy @ 2:24 pm

In under three weeks since it was launched, GraphSketch has now been used to create (over) 10,000 graphs. It also has had over 3,500 visitors, coming from every continent except Antarctica, though many visitors haven’t graphed anything (and many visitors have graphed far more than average). Work on new features (parametric and polar graphing, among others) will likely resume after school is over, as I still have three finals remaining, and am now off to continue studying for a math final.

At any rate, thanks to everyone who has promoted GraphSketch in one place or another for making it so successful.

Andy Schmitz

P.S. If you have any suggestions for GraphSketch itself, the original post on it is still probably the best place to leave them, as I’ll check back there for ideas when I’m working on it. Thanks!


Launching Recycling Reminder

Filed under: General, Hacks, Programming, Technology — Andy @ 10:37 am

Well, this was written way back when it seemed like a good idea, and it’s finally polished enough to actually release. Yay, something I actually finished!

On the off chance you might have some recycling that needs to be taken out (and you should..), this random little tool will let you set up a weekly reminder (an SMS message, actually) to actually get it out to the curb. It’s been working for me (and a few others) for several months now, so I’m fairly sure it’s stable.

So, if you’re (partially) responsible for getting your recycling out, go head over and sign up right now at Recycling Reminder. You’ll need a standard cellphone of some sort. It’s completely free, though clicking the ads now and then gets me a few pennies, if you’d like.

Please email me or leave a comment (or something) if you happen to find it useful, have a problem, or anything else. Thanks!



Kids these days

Filed under: Technology — Andy @ 2:09 pm

What happened to the old, existing protocols for everything? Why did JSON and Web 2.0 replace lightweight protocols for chat, discussions, and communication?

For: …we already had: …but everyone’s moving to:
Chat IRC, talk, Jabber (or AIM, if you must) Meebo, Facebook Chat, Campfire, Chatterous
Discussion Usenet, email, elists Google Groups, Wikis, Plurk
Status .plan files, Jabber status Twitter, Plurk, Facebook status

It’s not that the new alternatives aren’t necessarily any good (though some of them are missing features or tend to be unavailable), but that their functions already existed, for the most part. Strange.


Edit: Added Chatterous. Also, okay, “Y’all these days.” As apparently many of y’all aren’t kids.

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