Monday, December 19, 2011

Grades

I have just finished grading the final exams, and the average was about 82%. I was pretty happy with how it came out, and most of you didn't end up changing your grade going into the final exam by very much. I should have your grades posted Monday evening some time, and will try to email each of you a grade breakdown as well. 

Wednesday, December 14, 2011

Final project videos


All the final projects finished up nicely, and we have video and code for all of them. So, in case you want to try them out, here is some information:

4 bit maze [Daniel Jenkins, Andrew Wagner]:

Mr. Jenkins and Mr. Wager implemented the Arduino four bit maze found here, and explain their project in this video.

d-pad/joystick controlled Etch-a-Sketch [Coston Rowe, Andrew Hicks, David Thompson]:

Mr. Rowe, Mr. Hicks, and Mr. Thompson used Parallax servo motors and a homemade joystick/d-pad to remotely draw on an etch-a-sketch. Their Arduino code is here, and they describe their work in this video.

Daft punk helmet [Jacob Moxley, Cameron Darling]:

Mr. Moxley and Mr. Darliny used an Arduino Uno and the LoLShield they assembled to create a Daft Punk-inspired helmet with scrolling messages. Their code was based on cibomahto’s LoLShield library, with some modifications to fix lower-case letter display and implement sprite-style graphics. They describe their work in this video.

RFID tunes [Ali Cortez, Max Peeples]:

Mr. Cortez and Mr. Peeples implemented a tune generator based on reading RFID cards that encode pitches, notes, rests, etc. Their code and all project details are here, and they describe their work in this video.

“Incredimen” pseudo-Theremin [David Gillespie, Derek Brazzell]

Finally, Mr. Gillespie and Mr. Brazzel made a pseudo-Theremin. The main differences from a traditional Theremin are the use of lower frequency oscillators (~80kHz) to make things easier, and using a op-amp simple summing circuit for multiplexing rather than a more complicated mixer. The use of lower frequencies does impact the sensitivity, but it still works great and sounds very, very weird. They describe their work in this video, which apparently they spent quite a bit of time on!

If you want more project details, you can contact me and I'll either tell you what I know or put you in touch with the students who did the project.

Tuesday, December 13, 2011

Final exam hints

The final exam is really difficult. My wife asked me if it was difficult because you all hadn't studied enough or something, and my reply was "no, they have studied, it is just really difficult." Then I decided I should probably help get you started a little bit ...

Even with massive hints, some of them are still very hard (or messy, or both). They are more open-ended problems than you are probably used to, requiring approximations or assumptions that you have to come up with on your own to generate reasonable solutions. With one exception, not the sort of problems where you just identify formulas or set up an integral or two. If there is a lesson here, I guess it is that realistic problems are messy and difficult, and half the time you don't even know where to start. The trick is to figure out how to make it look approximately like one of the nice tidy textbook problems, without sacrificing too much in the way of accuracy or realism.

Anyway: here are the massive hints I spoke of. I also corrected a typo in number 4 - it should be "b/a" in the log, not "a/b".

Monday, December 12, 2011

Your final exam

Here you go. Feel free to ask questions about the problems if something seems unclear, or you don't know how to get started. I'll clarify what I can without giving away too much ...

Friday, December 9, 2011

Dell laptop cord left in lab

I found a stray Dell laptop power cord in the lab after class today. I'll bring it to the main office (206 Gallalee), if it is yours you can drop by to claim it from 9-12, 1-4:45 any weekday.

Wednesday, December 7, 2011

Continuing your projects

Just a thought: if any of you need PH elective credit, and would like to continue to refine and complexify your final projects (or something else), I'd be happy to work with you next semester via an independent study course. If this sounds like something interesting, let me know and we can talk about the details.

Tuesday, December 6, 2011

Final projects and "report"

Well, everyone's project basically works. Most of you have a little polishing to do, but the basic idea worked out for everyone, and you managed to build some pretty cool stuff. It would be a shame if this information were lost, right?

Keeping that in mind, and the fact that nothing can really be deleted from the internet, I've decided to change the final reporting requirements. In your favor, as it were. Rather than writing a final report at this late date, I want you all to make short videos describing your project, along with a demonstration of how it works. There are no real restrictions, just a few guidelines & suggestions:

  • You don't have to be on camera yourselves, just your project. You do have to speak though.
  • A few minutes is enough, if you can describe the project well enough
  • You should briefly describe the point of the project, showing diagrams or schematics as necessary (say, on the blackboard or a sheet of paper) so it is clear how you made it work
  • Describe the hardware and code required to make it work, in brief. Include links with the video to make this easier (see below).
  • End with a live demo of the project, showing its basic functionality, operation, and major components
  • Upload to YouTube or your preferred time sink
  • If you made heavy use of particular web pages (e.g., schematics, code, etc), send me those links.
  • The video + links should be enough for a reasonably proficient tinkerer to reproduce your project.
  • Do plan a short script or sketch of what you want to do for your video, it will not go well if you just start shooting and rambling at the camera :-)

I'll post links to the videos here, along with files of any schematics/code you think is non-obvious. The basic idea is that should someone like yourselves search for a similar project, they'll find your video and any interesting supplemental information required to make it work. Maybe then they will have an easier time doing it themselves, or at least be inspired to try it out, having seen it is possible. Many of you came up with your projects this way, so you'll be paying it forward a bit.

During Wednesday & Friday's classes, I'll bring in my camera, phone, and laptop (all of which take video), or you can use your own phones/laptops/etc. There should be enough time during those two class periods for most of you to complete your short videos, or we can work out another time for you to come in and do it outside of class if you like. For that matter, if your project is portable, you can do it in your dorm room.

So, all you really need to do for your projects at this point is (1) polish as you see fit, (2) take a video, (3) turn in any code/schematics/links/etc to include as supplemental information with the video.

Grading will count one lab report grade each for: (1) video quality/clarity/etc, (2) functionality of the project (how well it worked), (3) overall polish of the completed project (hardware & code), (4) creativity in coming up with and implementing the project. That means the final project is just under half your lab grade, which is itself 15% of your overall grade. It is a group grade, each team member gets the same grade for the final project.

More details and discussion in Wednesday's class.

Friday, December 2, 2011

Notes on EM waves, radiation, etc

Here are some notes on radiation, EM waves in conductors and insulators, etc - the stuff we've been covering the last several lectures. They are rather long, and incomplete in places ... but they do cover some interesting things I didn't quite get time to go over in lecture.

The first part is deriving the radiated power by accelerating charges, and applying that to several systems (oscillating charges, circular motion, etc.). The second part is deriving the blackbody radiation, which we did not cover (you'll see this in PH253). The last part is EM waves in solids, complex conductivity and dielectric functions derived from a model of oscillating charges. An appendix shows how to derive B from E in a moving reference frame.