27 October 2012

KawaiiKart Mega Update

Quite a bit of time passed since my last update and quite a byte has changed! (well, maybe not 8x as much, but you get the idea.) KawaiiKart is almost finished designed! Here's the latest model:



The box behind the seat is the 35cc engine. I also have to install the steering assembly at some point and decide what to do with the extra lengths of aluminum on the outer frame of the chassis.

The steering is still a little sketchy (I had to remove some (important) constraints to make Autodesk happy), but it looks fine! I still have to work out how the steering column works; my plane projection for the loft on the steering column is very sketchy. Turns out the angle of the steering column with respect to the chassis is 35 degrees, not 45. No big deal, band saws are my friends.

I also have some design updates. I'm ditching the hubmotors because time to production is way too long compared to using off-the-shelf components. I am willing to manufacture battery packs though; a 16-cell pack isn't very hard.

If you're interested in following my progress, check back every so often; I hope to make lots of progress before the new year! In fact, my BOM is almost done!

22 October 2012

I love you EVGA

The Nvidia-only GPU and motherboard manufacturer has the best customer service ever!

Remember the GTX 460 2Win I got from eBay? It stopped working a couple of weeks later. I instinctively opened an RMA request on EVGA's website and mailed the defective card in, only realizing after I dropped it off at USPS that the warranty-is-void sticker was removed! I panicked and prayed that EVGA would be nice and send me a replacement anyway.

Less than a week later, EVGA calls me, but I didn't pick up since my 6.02 exam was about to start (literally). A couple days later I receive email from EVGA that a replacement is coming my way! I checked the serial number and it indeed is not that of the one I sent in! Woo!

I finally took the time today to retrieve it from desk and test it. After booting my computer with my 30" plugged into the unit, I got a black screen, so I rebooted the machine. No luck. I then installed my 8800GTS (another EVGA card), plugged the 30" into that, and the machine booted with video. It's a bummer that the card has issues driving my 30", but I bought it for compute, so no worries.

I'm convinced that EVGA was nice only because I mentioned that I have an SR-2 in the RMA request.

Here's to two more?

09 October 2012

iPhone 5: First Impressions

The phone comes in immaculate packaging, as with any Apple product. I believe the iPhone 5's box is moderately smaller than that of the original iPhone's. Inside the box, you will find the iPhone 5 sitting at the top layer, underneath a packet of manuals other textual paraphernalia, and finally a 5W USB charger, Apple EarPods, and a Lightning cable.

I immediately saw two imperfections with my phone, both at the lower right on the aluminum. They're at most 0.5mm wide; I don't own a micrometer or have one handy, but they're certainly less than a millimeter in width. That said, I will not be exchanging the phone or putting it in a case.

When you pick up the phone, you notice how thin and light it is. 0.8oz is nothing impressive on paper, but it is very tangible in your hand. In addition, the thinness of the phone is tangible as well, but not as much as the lack of weight.

The phone boots very quickly in about 7-10s. You are then greeted by the setup assistant, which works just like the one in iOS 5. I restored my phone using my iPad 2's backup on iCloud, which took no more than two minutes.

Moving around in iOS 6 is very zippy. I haven't yet felt any lag navigating around or while using apps. Gaming is butter smooth as well; Real Racing 2 flies, although extremely cramped on a phone compared to on iPad. The phone stays cool while gaming.

I have noticed one glitch, probably caused by video drivers, but it might be hardware related. The screen will display about 5 rows of scrambled lines when I switch between the numbers keyboard and the qwerty keyboard while typing my password for the App Stores. This bug is pretty hard to reproduce; it's only happened three times to me so far.

I also noticed that the phone gets quite warm while browsing on LTE. The aluminum especially acts like a fantastic hand warmer (will definitely be useful for the upcoming Boston winter).

Battery life has been great as well. I got a bit more than 10 hours of use surfing the web, playing some light games, and listening to 5 hours of music on and off. Push Exchange was on the entire time. I predict that I will have to charge the phone every 1.5 days, compared to every night with my previous phones (iPhone, Dell Streak, HTC HD2).

The included EarPods are decent. They have more bass than Apple's in ears, but cannot touch my B&W P5's or my Sennheiser HD428s. The treble and midtones are not as warm as the P5's. Unfortunately, without any removable grill design, they look like they will be jammed by earwax by some point in the future. That said, they're definitely a step up from the previously included earbuds.

Lightning works well. The cable is indeed bidirectional and it's also very small. I'm not bothered by the lack of compatibility with old accessories because, well, I don't have or use any besides the cables.

11 September 2012

New School Year, New Strategies?

I'm back at the MIT and junior year started off with a sizzle today. Having barely survived the past two years, I figured I should revise my various strategies in hopes for a more successful remaining two years. In no particular order:
  • Digital handwritten notes: has a more similar tactile feel to writing on paper than typing on a keyboard, yet makes my notes more accessible for studying and saves organizational issues. Combined with taking iPad instead of my laptop wherever I go, this saves a considerable amount of weight.
  • Make local git repositories for coding classes: just in case I accidentally my code in between. 
  • Run/Jumprope/DDR: sufficiently tires me out so I maintain my (sleep) schedule. Plus aerobic exercises burn way more calories than resistances ones.
Classes have been fine so far; it's only the fourth day, after all! 

6.02 Intro to EECS II: This class is about compression and digital signals, with which I don't have much experience. It should be relatively straightforward since it's an intro class.

6.837 Graphics: This class is about all things computer graphics, from physics engines to modeling to ray tracing! It's also in C++, which is convenient, but could potentially be frustrating. Bummer that Fredo is not teaching it this term.

18.100C Intro to Analysis: This is a Death Class at the Institvte, which should definitely give me a run for my money. I haven't done math in quite some time, so it should be (refreshingly masochistic and) fun.

18.337/6.338 Parallel Scientific Computing: I'm pretty sure this class has already won my heart, if not for the material taught, but for our class [super]computer. We will be using a state of art 8-processor Sandy Bridge-E beast, with 80 cores and 1TiB of RAM! This baby will absolutely crush my SR-2 in (embarrassingly) parallel tasks, but I'm sure will lose miserably in single threaded tasks (that don't demand too much memory, of course). Hah.

21F.107 Chinese I Streamlined: This class is for people who have conversational skills but do not have much reading or writing proficiency. Hopefully all the memorization won't kill me.

Speaking of the SR-2, it is sadly out of commission until about next week because:
  • I left the OS X boot flash drive at home (NJ), which is pretty unfortunate. I did put the aml file onto the disk, but that did not work.
  • The AMD 6870 that I was using is now sold to a friend. Well that's a non-issue now because my new GPU came in yesterday!!
  • Both plastic motherboard standoffs were broken during transport. I purchased some epoxy from Home Depot this past summer, but never got around to re-securing the mounts. I also need to cut the hole in the back for the IO ports, which I may get to this weekend.
Obligatory room pics. 

My desk has turned into a parking lot. Name all the vehicles!


New GPU! It's an Nvidia GTX 460 2Win I bought on eBay. (oops camera rotate fail)

Steve Jobs is finally hung! (hanged?) Also the iMac makes an excellent timepiece.

04 September 2012

PhotoNotes: Alaska

Inspired by my professor Frédo Durand, I've decided to write about my photography adventures, including practical advice and whatnot. I hope you find it useful!

Practical Details

Weather

Alaska during late August is mild, around 5-20ºC depending where you go. Anchorage and the south were quite nice, at around 10-20ºC, but Denali was quite cold. All the areas were decently rainy. I think we got lucky and dodged most of it, having only rained hard one day when we were driving from Anchorage to Denali. It does drizzle often though, so make sure you protect your gear as necessary! The coldness does get to you while hiking, especially if it's raining, so bring gloves!

Transportation

We rented a car for the two weeks we are here. We got a Chevy Malibu 1LT from Alamo, which was quite decent, save for the abysmal quality interior plastics, which showed every scuff and scratch. Unlike the Prius rental from last summer, this car doesn't struggle at speeds near 80mph. The roads are incredibly well paved, have gorgeous scenery, are not crowded at all, making driving a pleasure.

Disk Space

You are going to someplace exotic and probably a once in a lifetime trip, so shoot RAW! Beware RAW files are huge; it's more or less a 1.5:1 ratio between file size and resolution. My 1D3 was generating about 10-15MB files and my 5D2 at least 25MB. This explodes if you're shutter happy; I can easily shoot 30+GB of photos on an action-packed day, especially in your first few days since everything looks exotic and snapshot-worthy. My biggest gaffe was not bringing enough external storage, with about 60GB free space altogether.

Special Photography

Car

I think this is common sense: to get the best photographs from the car, roll down the window to shoot! You never know how smudges on the window will ruin what may be an excellent photograph. Take care to use a fast shutter speed, otherwise you may get motion blur.

Boat

A day cruise will mostly likely be in your itinerary; I went on two. They're fantastic for getting up close to glaciers and to see sea life. Depending on the size and then length of the cruise, you may have to compete for a good spot to shoot the animals. The decks are especially windy and cold in August, so dress warm so you can keep your good spot. The boat also rocks quite a bit, so image stabilization won't help much. You won't be close to the animals (at all), so bring a (super) tele! I was very sad that my 70-300L on an APS-H (1.3x) sensor was not sufficiently long.

Zoo

There's a nice zoo in Anchorage that's worth checking out. There's no indoor exhibits, so leave the fast prime at home. However, do bring your standard and tele zooms, as you can get quite close to the polar bears and petting zoo animals.

Birds and other fast moving critters

You'll want to practice AI-Servo or equivalent continuous focusing mode beforehand, otherwise you will get a lot of sort-of out-of-focus shots. Also good panning technique might be helpful if you can't shoot at a high shutter speed.

Animals

Moose

Moose are large animals that sometimes graze along a road. Be prepared to stop and shoot!

Mountain Goats/Dall Sheep

Dall sheep graze very very very up high. You'll probably need an 800mm lens to get close to filling the frame with a herd.

Sea Otter

Sea otters are the cutest. They're pretty shy animals, so they try to avoid the cruise ship unless you get lucky. You'll want something longer than a 400mm lens (35mm) so as to not rely on luck.

Sea lions


Sea lions enjoy lying down on rocks to absorb heat. They are easily heard by their bark.

Seals

Seals are timid animals. They highly enjoy sunbathing.

Jellyfish

Orca

Orcas are usually seen in herds. They don't normally show off with a full body out of the water jump.

Humpback Whale

These behemoths are also quite hard to get. If anything, they just show their tail. 

Porpoise

Porpoises are pretty annoying. When they come above the water surface, they make a huge splash, so you have to shoot them when they're about to come out or else you'll get a huge splash.

Eagle

Eagles are fast flyers! They generally fly quite far away, so you'll want a supertele. Rarely do you see them stationary, except at the zoo.

Puffin

Diving Puffin

Horned Puffin

Tufted Puffin

Hello there!

Puffins are pretty cute as well. There are two kinds in the area, the tufted puffin, which has crazy hair, and the horned puffin has an interesting horn-like pattern behind its eye. They dive under water to get the fish up to the surface, at which point they torpedo up and grab a fish.

Common Murre

Common Murre are small penguins that inhabit crevices of rocks. They're all black and white, so it's pretty easy to overexpose them. The easiest way to practice is to shoot seagulls, since they also have a lot of white.

Musk Ox

These don't really count as I photographed them at the Alaska Wildlife Conservation Center. However, you might just get to see them sparring or bullying each other, which is a treat compared to lazily grazing.

Bears

These also don't count since I photographed them in captivity.

Caribou

These also don't count since I photographed them in captivity.

Little Wild Critter


Equipment

Lenses

For this trip I brought along a 50 1.2L, a 24-105L on my 5D Mark II, and a 70-300L on my 1D Mark III. The 50 was mostly unused, save for some shots on the airplane. The 24-105 on the 5D is fantastic; you get an useful range for landscapes and other nearby things. The 1D3's crop factor on the 70-300 is quite nice, giving a ~400mm focal length on the long end, which turned out not to be long enough. To add insult to injury, the 70-300 does not support Canon's extenders. I wish I had  gotten the 100-400; they're about the same price, but the 100-400L has a bit more reach and supports extenders, at the cost of being much older and weighing a bit more.

Carrying gear

For most of the time, I had the cameras around my neck, which worked fine. I wasn't afraid of rain since the 1D3 is fully weather sealed and the 5D2 is partially sealed. I stashed them into my Thule crossover backpack at the end of the day.

Misc.

I had a Slik tripod that only got used once for a night shot of the starry sky at Miller's Landing, but the shot was accidentally deleted.

There were definitely deep pocketed amateurs or professionals in the wild.

Locations

Anchorage

Anchorage is a pretty pathetic excuse for a city. If I weren't told what the name of the place was, I would have assumed it was a suburb. It may not be pretty, but it has some great hiking trails at the Flattop Mountain in Chugach State Park around the perimeter. Plus, it has Alaska's only Apple Store in the 5th Avenue mall!

Alaska Wildlife Conservation Center

This is a little zoo-like area outside Anchorage along the Seward Highway. It's a pretty large portion of land in which animals such as musk ox and bears roam. It's somewhat expensive, but worth a visit.

Kenai Peninsula

Seward
On the outskirts of Seward is Exit Glacier, which has an easy 1mi hike to its viewing spot. Seward also has a fantastic glacier tour, from which we saw the Aialik Glacier and a plethora of wildlife. There's also plenty of recreational activity to do, such as camping, fishing, and kayaking.
Kenai
There's not much in the city of Kenai, but there are a few hiking spots and a beach along Sterling Highway outside it.
Homer
Homer is a quiet suburb and is known for its Halibut fishing industry. There's a small gem of a restaurant called Cafe Cups, which serves phenomenal steak and seafood. The town is very hilly and walkable, especially its 10 mile coastline.

Denali

Denali is the largest national park in Alaska. It's even bigger than Massachusetts! This vast space is filled with wildlife and plenty of snowy-capped mountains, including Mt. McKinley, the tallest mountain in the US. Unfortunately, you'll need to take one of their tour buses (a minimum 6hr ride) into the park to see more wildlife, since they don't hang out much near the entrance (you're only allowed to drive the first 15 miles). The moose seem to come out and graze in the morning around 11am, but no bears. Mt. McKinley is also hard to spot since it's hidden in the clouds for all but 60 days. The aurora borealis is also pretty tricky; the area is always cloudy and people claim the best viewing time is in September.

24 August 2012

Dealing with Ruby's different versions

To my dismay, Ruby on Rails seems to be linked deeply into OS X's frameworks, which I don't want to mess with. Some poking reveals that the default installation, version 1.8, is in a system framework called Ruby.framework. The normal method to updating such tools is to remove the old version and then install the new one, but I did not want to take the risks this time. Turns out there's a great tool called rvm that will manage multiple Ruby versions!

Complete instructions are here: http://bigdiver.wordpress.com/2011/11/24/update-ruby-and-rails-on-mac-os-x/

They're written with OS X in mind, but adapting them for any Linux system should be trivial.

13 August 2012

The Ideal Notebook

If I didn't have my monster of a Hackintosh already.

Presenting the Mac Pro to go, or the retina MacBook Pro. Comes with a built-in 30" screen!


Clearly the first thing I do is run the notebook at native resolution, an incredible 2880x1800. The menu bar nearly disappears, while the dock becomes reasonably-sized. For those incredulous readers, my 20/13 eyesight is sufficient for this resolution. :-)


An 1880px vertical is quite nice for web designing, albeit highly misleading for emulating typical usage.


Day-to-day use. I can fit a bunch of apps onto one virtual desktop, which is how I work on my 30" Dell. It's huge compared to my MacBook Air, which has a 1440x900 screen, and a lot less claustrophobic than my six-year-old MacBook Pro, which has a 1920x1200 screen.

30 July 2012

Safari 6 View Source

To my surprise (not a good one, either), Safari 6 has done away with View Source in its vanilla state. I was shocked and disappointed when I was trying to view the source of a test page:


On the bright side, it's buried in the Develop menu in the snazzy console:


But yay, syntax highlighting!


26 July 2012

Two small lemmas

Two friends kindly pointed out to me that I will have power issues next year at MIT. Since most dorm rooms have one circuit (good for about 2kW), I can at most run two out of the following three items simultaneously: {computer, refrigerator, air conditioning}.

A friend suggested that I schedule all rendering and compute jobs late at night since the power grid will not be as hosed and to automate the modulation of my fridge/AC usage during the day. I also won't be helping the situation with a near-imminent upgrade to dual Nvidia GTX 580s, either.

15 July 2012

SR-2 Adventures, Part III

I recently ordered a third power supply (don't worry, I'm not modding this one!) for my hackintosh. It's a server grade unit rated at 1200W made by PC Power & Cooling, which should be sufficient for further upgrades, such as dual Nvidia GTX 580s (for raytracing, of course). At first, 1200W seems gluttonous, but we note that overclocked processors can consume up to 200W, since power is approximately proportional to clock speed squared.

Now onto the fun part: overclocking! Recall that this system uses two Intel Xeon X5650-like [1] chips sourced from eBay. To get up to 4GHz, we use the following voltages:
  • Disable Vdroop
  • Set Vcore to 1.35
  • Set Vtt to 1.35
  • Set DIMM to 1.65
  • V_IOH to 1.40
Then in the signal tweaks menu:
  • Set QPI0 to -86
  • Set QPI1 to -16
Then jiggle the settings in the CPU menu:
  • Enable Speedstep
  • Enable Turbo
  • Disable C-state
Note that enabling Turbo will get you a 21x multiplier, or so people say. Finally set BCLK to 191 and voilà, a 4GHz 12-core monster! Sadly OS X does not notice the turbo multiplier at 21x, so it won't show 4GHz in System Profiler. In any case, here's a screenshot of the system at 191x21:

Issues

Mac App Store can't verify computer

This one is annoying. I haven't bothered to fix the issue for this hackintosh (I did it for my single processor computer), but the solution involves deleting the network interfaces file, rebooting, and readding the interfaces in System Preferences. I will update this section once I fix the issue.

Flaky PS2-USB adapter

For BCLKs @ 195 and 200 I noticed that my keyboard would work for about 10 seconds after being plugged in and then it would stop working. I check the Console, which says

IOUSBPipe:ClosePipe for address, ep 1 had a retain count > 1. Leaking a pipe
IOUSBPipe:ClosePipe for address, ep 2 had a retain count > 1. Leaking a pipe

I am convinced that this is due to the overclock being unstable. The problem goes away when I'm running at 190 or 191. I also noticed that USB mouse and ethernet adapter aren't flaky at all, but my USB headset does develop crackling noises after a short while (under 10 min).

It's heating up my room!

Yep, sadly this rig is overpowering the air conditioner in my residence. I can feel it spewing hot air out the back. :(

[1] Duck test, but for CPUs: If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.