Piece of Mind

I love this feeling.

After some sweaty late night tennis, hop on the car, start the engine, knowing where I am and where I want to go (home), but nothing in-between.

There’s a compass.

I am terrible at directions.

So I just drive in the general direction of where I think home is (I can do that thanks to the compass), and hope I’ll eventually end up on one of the few roads I know, and I can get home from there.

I’ve done it a few times and I think I’ve taken a different route every single time. Oftentimes I don’t even know what direction I am driving without looking at the compass. When I reach intersections… well there’s a 2/3 chance of getting it right (assuming the target is in one of the 2 quadrants in front).

From South Arm to my house at Blundell @ Gilbert, I think I’ve even gone to Granville and back once (those are roads in Richmond btw).

The stars are beautiful, and there are very few cars on the roads. The silence is relaxing. I don’t mind driving a little longer.

Try it some time! (I can help you get lost if you want. I’m GOOD at it)

Just sent my oscilloscope PCB for manufacturing, and it will take about a month, so I’m thinking about my next project now .

I’ve always wanted to build something that flies. That’s my childhood dream.

I think it’s about time.

Did quite a bit of reading over the weekend, end up deciding on a quadrocopter.

There are basically 3 types of flying machines -
1) Lighter-than-air (LTA) vehicles – things that use hot air or helium (or *gasp* explosive hydrogen) to float in air, and motors just for maneuvering. Like an airship.
2) Fixed wing aircrafts – airplanes. Aerodynamically stable (if engines fail, you can still glide it back home).
3) Rotary wing aircrafts – helicopters, tri-copters, quadrocopters. Aerodynamically unstable, and requires precise electronic control to maintain stability (if engines fail, it will enter free fall immediately… bloody!).

Airplanes would be too hard on the mechanical side, since I know nothing about aerodynamics.

I was debating between airship and rotary wings… airships are just not cool enough =P and they are heavily influenced by wind, which may suck.

And quadrocopter is apparently the easiest to build/control among all rotary wing crafts, so I’ll start with that.

In my dream, it has a range of about 1km, sends a live video feed, and allow remote control, as well as GPS based auto-pilot (auto return home and waypoints).

Major challenges -

Control

For the thing to be stable, the rotors have to make sure there is no tilt on all 3 axises of rotation (roll, pitch, yaw). And to do that, it must know its own orientation, which is a lot more difficult than it sounds, requiring an inertial measurement unit (IMU), usually consisting of a 3 axis gyroscope and a 3 axis accelerometer, along with a few other things (GPS, magnetometer) to correct long term drift. This alone will cost >$100. Also very complicated algorithms and crazy math.

Radio

High frequency = high bandwidth and low range. Vice versa.
To stream video, I’ll need at least a few hundred kbit/s, which means it will probably have to be 2.4GHz.
That will limit my range to about 1km with line of sight, but I’m hoping that won’t be a problem…
Lower frequency radio can do a few kilometers, but at tiny fraction of the bandwidth.

Power

I looked at some motors used by other people. They draw about 10A (yes! 10 AMPS!) each, for a total of ~40A.
That means I will probably have to ditch my favourite NiMH, and go lithium polymer. Both for the energy:weight ratio and output current.

Regulation

They (the government) don’t want whatever you build to crash into a 747. Which sounds reasonable.

Transport Canada doesn’t seem to have any regulations for “model aircrafts” except it must be <35kg. I have already emailed them for clarification.

I want this thing to be classified as a “model aircraft” because it’s the only class that doesn’t require any license/certification to fly.

In the US, they also have a restriction of a maximum altitude of 100m. That would be fine with me, too. I’m not going to launch my chopper into low earth orbit or something =P. For comparison, commercial airliners fly at about 10km – 100 times higher.

They also have a line of sight requirement, meaning you must be able to see the aircraft with naked eye at all times. And if it’s autonomous, you must be able to do manual override to get it out of trouble any time.

I’ll get to work =D.

There are 2 ways to do everything – there is the right way, and then there is my way.

This is my way.

3 big chunks of ice with a little bit of water added to increase surface area.

I think the effect is more placebo than real lol. But still!

Experimenting with freezing point depression now. Theoretically, 10% NaCl by weight will give me a freezing point of -5C. We’ll see…

In an ideal world, I can reuse the salt too!

Just picked up my lovely (shiny) saxophone today, after not even seeing it for the past 3 years.

The sound was nothing short of remarkable, depending on how you look at it – a perfect reproduction of constipation noise, interleaved with hyper-modern randomly-variable rate uncontrolled vibrato.

The victim. No photoshopping! It IS shiny .

I think I deserted it right after I did my last RCM exam (there was a time when I thought paying someone to tell me how good I am is a terribly awesome idea).

Sharing the love!

Warning: This post may contain spoilers for Toy Story 3. I’ll try my best not to tho. If you think you’ll ever want to watch it, proceed cautiously. If you haven’t and don’t think you will, think again =P.

hypocrite hypocrite hypocrite hypocrite hypocrite hypocrite hypocrite hypocrite hypocrite hypocrite

I’m the biggest hypocrite in the world.

After writing a whole blog post about how silly this 3D thing is, I just went to watch Toy Story 3, in 3D =P.

Some things are worth dying for.

Toy Story is worth living for.

I’m not sure if it’s the nostalgia or Rex (the dinosaur learning how to rawr), but I feel so kiddo again.

It’s one of those films that you don’t have to think about deeper meanings, or try to decipher some hidden message, or facts of life, or whatever.

It’s just toys. So little yet so much (no, this is not an attempt to sound profound). It’s all in the details. The character development is crazy for just chunks of plastic. And then their interactions and the lol moments take it to infinity and beyond.

The 3D is quite well done, too. There is no “dragons and demons ripping mortals apart”, but it makes the film so much more vivid. And it’s not grossly over-exaggerated like some other 3D films that just want to show off the technology.

Well worth the extra $4.

You’ll never be the same again! Well, not for a few hours at least.

A few weeks and a few swearing sessions later…

Congratulations!!
The layout is complete and has no shorted nets.

2 layers PCB. Probably going to get it manufactured by Olimex.

This is my first board ever, so I’m guessing there are tons of errors everywhere. lol.

All the surface mount caps are the same type (0.1uF ceramic). I used through hole capacitors for the other few because SMD capacitors tend not to be labeled… the labels would be too small to see anyways.

2 connectors on the left are BNC (oscilloscope probe connection). Goes to analog frontend (the part without ground plane), then the programmable gain amplifier (U1), then 2 ADCs (U3 U4), then FPGA (U6). U10 is the 25MHz oscillator for the FPGA. U5 is the DAC used to set voltage offset. U7, U8, U12 are voltage regulators. U11 is charge pump doubling inverter to generate negative voltage for amplifiers. U9 is USB interface chip. The connector on the right is USB-B.

In case you are wondering, most of the holes (181 holes!) are vias (connections between the 2 layers), not for soldering components. So no, I won’t be spending the next 20 years of my life soldering this board =P.

Next step, throwing a pile of money at Digikey!! (very exciting)

Actually, I think I will solicit some feedback from random forums first.

The layout file in gEDA PCB format -
http://cyberfish.wecheer.com/tmp/board.pcb

Feel free to poke around.

On Debian/Ubuntu, do “apt-get install geda”, and “pcb board.pcb”.

I don’t think gEDA runs on Windows. Sorry. Some people reportedly have successfully built it on Windows, though.

A friend of mine, who prefers to stay anonymous for personal security (duck!), drew this.

(click for full image, or mouseover to be enlightened!)

She may not have her own exhibition at the art gallery yet (a post on my blog is almost as good), but this is very promising talent!

It’s the minor league for xkcd.

If you are the author of xkcd and wants her to join you, or wants to sponsor a young promising artist, or just want to have a good time, call her at
778-372-1287

Satisfaction guaranteed.

It’s not who I am underneath, but what I do that defines me.

- Batman

Nevertheless, I believe something that has been representing me for so many years deserves at least a blog post for its retirement.

2003 – 2010 (aged 7)
My registered trademark, the “><((((->” MSN display name, will be no more. So long, and thanks for all of the one fish.

It’s about time to move on.

It has been faithfully representing me on MSN ever since grade 7. Only the number of fins have ever changed, and that was accidental. I’ve also changed its swimming direction once, and exactly 1 person noticed =P (or at least told me they did).

I believe it was a modified version of some random ASCII art I found on the internet to match my online pseudonym (cyberfish), which has served me just as long.

I will probably change it in the next few days (I sign in from 4-5 places… so it takes a while to change them all). So take a picture with it, give it a hug, or even just a stare, while you still can .

The pseudonym, though, is here to stay, fortunately (for me) unfortunately (for it). Probably for life.

I’m not sure where the “cyberfish” came from. I think I just grabbed 2 random words from a dictionary, and stuck them together, hoping it will give me a unique identifier, and after 50 years, I’ll be able to google it and see nothing but my own stuff. Nope, lots of people are using it too.

People have said it’s girly. And I agree.

Girls are cool. I like girls. They are pretty (the pretty ones are).

I may not be the beast, but she sure is the beauty =D.

Just got my Nexus One! It’s gorgeous.

Similar specs to iPhone 4 (5MP camera with auto-focus, a bunch of sensors, 512MB RAM, 1GHz ARM CPU, etc), without the Communist Apple touch.

Can change the battery, has SD card (instead of way overpriced internal memory), has native msn client, has flash, and you can actually decide what you want to run on it =P.

Going to use it with Wind’s cheap data plan =D ($35 total for 500MB/month is amazing)

Got it without contract for some big pile of money. The Xperia X10 can be had for almost free with Rogers 3 years contract, but I don’t like contracts, and I don’t like Rogers (or any of the big carriers for that matter). Wind may not have cute animals on their site, but their attitude sounds so much better. They actually make sense.

It’s funny that I’m into smartphones because I don’t really talk on the phone all that much. About 2 seconds a day calling my mom to pick me up, and a few hundred texts a month to my dear friend Cindy about… things that you wouldn’t want to hear about. And then there are the occasional tennis invitations that always end up nowhere for some reason… But otherwise not much at all!

I use my phone as anything but a phone. I’m thinking about using a phone without a plan… hmm. I wish they would just sell data =P. Otherwise it will just be an expensive ebook reader.

Trivia: Linus Torvald, the “inventor” of Linux, also got a Nexus One! He is very picky about phones, and only buy phones that run Linux.

In my not so humble opinion, blogs are the second most significant invention in the history of mankind, after sliced bread.

When I first started blogging about 5 years ago (?), it was very different. It felt like an obligation. To readers. To “trends” (it was a trendy thing to do at that time, when everyone had Xanga, instead of Facebook).

I tried hard to be interesting, to not bore my readers to death, to have “something” to write. It wasn’t for myself. It was for “readers”. As if my blog really had any significance to anyone else.

Ended up writing about the weather every other day, and about how I have nothing to say the rest of the time, and things I pretended to care about, pretending to sound thoughtful or profound by copying and pasting quotes from nowhere. Then I pretended to be interested in some people’s blogs and leave comments hoping they will do the same because number of comments was a measure of personal worth, like how number of Facebook friends is now.

I’m not sure how I survived through that, but those were the dark days. That’s not the kind of blogging I am talking about.

As you can clearly see from this post, I have given up on trying to be interesting a long time ago (are you STILL reading?! =P). And obviously, my writing hasn’t improved one bit over the last few years.

It feels so much better. Now that I can write about what I really care about, and not worry about what people think (don’t count the number of “about”s in this sentence!). It almost feels like an extension of my consciousness (no, this is not an attempt to sound profound. Just a display of my confusion).

I don’t even proof-read my posts anymore.

I always feel a lot better when I put things down on paper (err. keyboard). Happy things, sad things, ugly things. Whether people read it doesn’t really matter.

And I just lied. If whether people read it or not doesn’t really matter, I could just write in a diary or something.

It does matter. It’s the feeling of sharing that brings relief and happiness. Knowing that someone somewhere on the internet is reading this post makes writing it so much more interesting.

And I know a few of my friends DO read my blog, instead of doing a million more interesting things they could be doing. And I would love to say I don’t care since that sounds so much cooler. But I do. I do get excited when I find out people read my blog.

So thank you . You have changed me. A little part of me is made out of you (how right does that sound?).

If you have never tried blogging, try it some time! (and remember to link me) It’s a whole new world.

Smoking marijuana would give you similar experience, but blogging is legal almost everywhere, not just in BC . Equally addictive, though.