2015

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Galileo Board Temperature Sensor

Published by on June 17, 2015 | Leave a response

My independent study project turned into a full-blown research project last semester. The project involves benchmarking lots of physical and virtual machines, which means the project involves generating lots and lots of heat. My equipment is in a room that has no air conditioning on evenings and weekends. I knew it got hot in there over the weekend, but I wanted to know: just how hot did it get?

So, using the Intel Galileo Board 2 I won at IDF2014, I cobbled together a smart temperature sensor. It uses a TMP36 analog temperature sensor wired to the Galileo’s Arduino-compatible analog input pins. With the Yocto Linux image on an SD card, a little Python daemon, and some /proc filesystem flags tweaked to control the Galileo’s onboard analog-to-digital converter, I can scrape data from the temperature sensor and make it available as JSON feeds, which were then read in by another script to be processed into a HTML report. It’s a little kludgy, but it works.

You can find the actual (current) feeds of the equipment room here. A glance at the week graph shows the pattern of air conditioning availability.

I’ll release the source code and write up step-by-step instructions soon.

 

How did I even…?

Published by on June 3, 2015 | Leave a response
How did I even...?

What it says on the tin. (Click for embiggened version.)

Photo of blown supply trace on motherboard

Back of motherboard

The trace appears to be the 3.3V voltage line between the ATX connector (pin 13) and the DDR2 RAM slots on a Micro-ATX motherboard. (Edit: DDR2 does not run at 3.3V, so either it’s going somewhere else or I have no idea what’s going on–probably the latter.) I upgraded the RAM from 2x1GB to 2x2GB, but apparently in the process I also upgraded from “working-but-wonky backup server” to “dead motherboard with a side of magic smoke”.

I’ve never seen anything like it. I’ve put disassembled and put together hundreds of computers and the worst damage I’ve ever caused is a broken header pin. The only thing I can think of is the RAM sticks (which are tiny half-height sticks) may have been damaged when I pulled them from another computer, or when I installed them. One of them has a pin that is discolored and raised away from the module. Unfortunately, I don’t know if it was that way before or after the trace fried.

I’m keeping the motherboard for soldering practice.

Another photo:

blown_trace_1

Anybody seen anything like this before?

Achievement Get: Bachelor’s Degree

Published by on May 24, 2015 | Leave a response
"I'd like to thank glucose, for allowing my brain to function..."

It’s 12:35AM so I’m not going to be very wordy. Here’s the upshot:

  • My mother and I have graduated from California State University, Sacramento, with our Bachelor’s degrees!
    • She now has a Psychology degree.
    • I now have a Computer Science degree.
  • I was the Student Speaker at commencement. Hopefully most of you that listened to it were inspired to go out there and do cool things.
  • I’m going to grad school.
    • CSUS for my Master’s degree.
    • Stanford or Berkeley for my PhD…eventually.
      • My dream: d.school. My Agile project management class did a presentation on it. I’d love to attend.
  • …but I’m thinking about getting into the Software Engineering field somewhere between the Master’s and the PhD. After experiencing the joy of working on a small team that got stuff done and had fun while doing so (courtesy of Senior Project, and literally the first time I have experienced this kind of team), I’m very excited about the prospect of working with people who love working with computer software and hardware…and who love working with other people.

Obligatory image of me being inspiring on four hours of sleep:

Me standing at the podium

“I’d like to thank glucose, for allowing my brain to process all those cat videos…”

I’m still waiting for it to sink in: we have our degrees.

Fun With Routers, part 2 – Netgear WNR1000v2 VC + OpenWRT

Published by on March 28, 2015 | 3 Responses

Garage sales. Garage sales are awesome. I picked up a Netgear WNR1000v2 VC router at a garage sale for $5 last year. That’s a bargain, until you realize that this router should’ve retailed for $5. The stock firmware is terribad and limited. A JavaScript bug prevents WPS from being disabled unless you visit the administration page using Internet Explorer. It doesn’t help that some of these units were modified by Comcast to only accept certain firmware updates, and then passed out like candy to clueless Internet subscribers who needed a troublesome device to scream at daily. (As if dealing with Comcast wasn’t bad enough already.)

Enough ranting. Here’s the cool part: OpenWRT didn’t support it at the time. No, wait, that’s not the cool part. The cool part is, I accidentally got a custom build of OpenWRT onto the thing after investing in a USB TTL serial adapter and flailing around with OpenWRT’s source code. Wait, that’s still not the cool part.

I don’t remember how I got it working. It was towards the end of last semester, and last semester was two forevers ago in computer years. I posted on the OpenWRT forum but didn’t get any response, and I didn’t know enough about OpenWRT’s internals to submit a patch, so I slapped my hackish build onto the device and immediately forgot about it.

But! A hardworking developer who goes by the handle SaltwaterC took the time to figure out this pesky little device and made some nice builds and patches. That’s the cool part. Thanks, SaltwaterC!

If you have one of these, don’t throw it out! They actually work great with OpenWRT, especially if you can rescue one from the bargain bin at your local thrift store.

Hello 2015!

Published by on March 27, 2015 | Leave a response

So yeah, haven’t posted in awhile. Life has been crazy, awesome, and aggravating all simultaneously. (You know, like it always is, just more so.) So what’s been going on?

Here’s the cliff notes version. Expect sporadic blog posts in the future about these subjects.

  1. Upcoming Graduations: Holy Educational Achievement Get, Batman: I will graduate with my Bachelor’s degree in Computer Science in May 2015. But what, you ask, what’s with the plural s? My mother is graduating too! She will be earning her Bachelor’s degree in Psychology this May. I’m so proud of her. She’s put up with all the stresses and pressures of college life, only in a sixty-something year old body instead of a twenty-something year old body. She came out on top anyway, because she’s awesome like that. Go mum!
  2. Prepping for Grad School: Because I like college too darn much. I’ll be attending CSUS in the Fall as a graduate student in Computer Science.
  3. Senior Project: Whenever I see a poorly-designed website or application, I snarkily call it a “Senior Project”. Is that derogatory to hard working seniors in CSC190 and CSC191? Yeah, but it pretty much sums up the Senior Project experience: chaotic and messy and all around annoying. And fun. (Sometimes.) Don’t get me wrong, it’s a very valuable course, but it’s also transcendentally irksome. (Sometimes.) Also, we’re learning like a year’s worth of stuff on the fly and stuffing it into a month or two, because we’re still learning how not to plan things. At least I have extra motivation to learn ASP.NET/C# and other cool things, like Selenium.
  4. Independent Study Project: Because why have one massive project to work on when you can have TWO? I’m working on a performance testing framework to do some performance analysis on virtual machines. The results of my project will be used to inform decisions on program contest judging systems.
  5. Supplemental Instruction (SI) Class: Two years ago, the campus gave me a classroom and a group of twelve nervous compsci students who wanted extra guidance in CSC20. By the end of the semester, my students owned the material like Horatio Caine owns bad puns. That’s apparently good enough for the campus, because it’s happened three more times. This is my fourth semester leading the CSC20W discussion section, and my first under the indomitable Dr. Krovetz. I have to step up my game to match him. Dr. Wang was cool, but Dr. Krovetz is the cool kid that all the cool kids want to be. I can’t just be competent any more. No. I have to be awesome. Like Batman. Batmaaaaaaaan. (Nananana nananana!)
  6. Teaching With Greenfoot: So Greenfoot is an awesome application for teaching the basics of Java programming and 2D game design to youngsters. But wait, you might say: Cody, you’re not that old–you’re only a few years ahead of most of your students! All right, okay, so I’m not that old; I’m in my 20s, but I’ve been doing the SI class long enough to where I call all of my students “youngsters” regardless of their age. However, in this case, I mean actual youngsters. Greenfoot is great for teaching kids how to program. It’s powerful enough (and complicated enough) to make fun programs, but it also offers instant feedback and scaffolds the boring parts of the program to bridge the gaps in a tween’s or teen’s attention span.
  7. Minecraft: I’m sorry. What is this “free time” thing you speak of? I faintly recall that I used to–no, never mind, tell me later; I have to go punch some trees. (I’m hoping to put my world map up on the blog eventually.)
  8. The Usual Horrible Abuse of Old Hardware: Actually, not so much. I barely used any duct tape this time! I had an old laptop with a Pentium P6000 CPU in it. It was so slow, it made baby kittens cry. (Okay, so it wasn’t that bad, but I wanted something better.) I gave it an i5 instead. And a SSD. And 8GB of RAM, because go big or go home.
  9. Hanging Out with Friends: So I’m generally okay at being social and just being part of a group (instead of teaching or leading it), but for some reason, I never really did it much before this semester. But now I have a group of close friends that I hang with on campus. We spend most of our time talking about Minecraft and making innuendo-laden remarks and listening to music and impersonating our professors’ voices and trying to dance and generally just goofing off. Yay for being a more emotionally healthy person!
  10. Working on my Driver’s License: Because who doesn’t want to strap themselves into a two-ton metal death projectile and go careening down the highway while dodging irritated drivers who think the speed limit is 85? I’m aiming to get my license by July.

So yeah, that just about covers it. If you’re looking for more sarcasm, go watch Minute Minecraft Parodies. And expect more posts from me in the near future.

-C