Random Thought: Adding Apples and Oranges

You can't add apples and oranges, but you can add the electrons, protons, and neutrons within them. In turn, you can add the subatomic particles that compose each of those...

So... I'm not sure how to respond to "you can't add apples and oranges".

Product: Solowheel

Found out my TA has one of these. SO COOL! A tad steep for my price range though...

http://www.amazon.com/Inventist-The-Solowheel/dp/B007Q3FZYK

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On the other hand, this guy built his own segway using only analog components. Very impressive. 

Issues with the AVRISP

Today, my AVRISP was having some issues where it was able to program via command prompt's 'make program' from Makefile, but I was unable to connect to the device using AVR studio.

[Silly] resolution: after reinstalling the software driver for the AVRISP, I was able to set the software fuses, as shown in the images below, and increase the speed of my chip's clock by 8 times by removing the CKDIV8 fuse.

Article: Tracking in Guns

Tracking technology is letting users who have never fired a gun before accurately strike distant targets.

http://arstechnica.com/gadgets/2013/03/bullseye-from-1000-yards-shooting-the-17000-linux-powered-rifle/

Nuances in Eagle

4/2/13

When making custom parts, the orientation of the symbol's pin labels cannot be moved because they are hardcoded as part of the object shape.
source: http://www.eaglecentral.ca/forums/index.php/mv/msg/31318/108035/

Enabling the layer color-selector to have additional colors - disable "alpha blending", which is a technique that allows you to see through top layers in order to see underlying layers.
source: https://forum.sparkfun.com/viewtopic.php?t=17027

Never Too Late to Get Started!

Sure, many people knew what they wanted to do since before their 20s. But for the rest of us, it's never too late. Keep investing capital in yourself; it'll pay off.

http://www.businessinsider.com/what-successful-people-did-in-their-20s-2013-3?op=1

Morning Workout

Incrementally working my way towards doing this every morning.

Life's Too Short to Worry About Shipping Costs

I am very ordering-averse because of shipping costs; they frequently bump up the price of what I want to buy by ~10%. But, like being uncertain about printing PCBs, you shouldn't let the fear of mistakes become a source of procrastination. Of course, you shouldn't just order whatever parts you feel like ordering at the moment, but when you're 90-100% confident in yourself that you've accumulated the right materials, don't waste any more time worrying!

Three sites that I have been quite happy with are OnlineMetals, Sparkfun, and McMaster Carr, because of the vivid part descriptions and resources that they have. It's not only helpful for identifying what I want, but I can also learn new things just by browsing their inventories.

Digikey and Mouser are good for electronics parts, especially in bulk, but it's hard to make sure you get the right thing on the first try. 

Article: Uncanny Valley in Animations

"One day, realistic animation will completely replace film actors. And then it will be software developers, not merely beautiful people, who form our celebrity class. There will be better movies, and it will be cheaper to go see them." -Dr. Noah Smith

http://www.npr.org/blogs/thetwo-way/2013/03/28/175635684/is-it-real-with-new-technology-has-activision-crossed-the-uncanny-valley

Article: Things KAJ wish he knew

"I wish I'd been able to ignore the physical differences as I can now and just sit down, preferably on a shorter chair than them, and just talk to them about movies and books and history -- anything but basketball," he blogged.

Other items on his list include better choices in automobiles, taking a more adventurous approach to vacationing, an earlier discovery of yoga and a better diet.

The Hall of Famer and NBA's all-time leading scorer also wishes he did a better job maintaining friendships.

"I wish I'd called more, visited more, and generally paid more attention to those people who were most valuable in my life," wrote Abdul-Jabbar.

He also regrets he didn't pay enough attention to business and his own finances.

"I thought that if I played exceptional basketball, all else would fall neatly into place," blogged Abdul-Jabbar.

http://www.latimes.com/sports/lakersnow/la-sp-ln-kareem-abdul-jabbar-shares-regrets-20130329,0,5995727.story

Article: Start making abstract associations

• What if you used computers as telephones?
• What would happen if you used a web site as a Word processor?
• Would people care about what other people are doing right now?

The people behind projects like Skype, Google Docs and Twitter all have one thing in common: They fused seemingly abstract concepts together. Taking what-ifs and testing them is a great way to start thinking of things in a different, more creative light.

http://lifedev.net/2008/07/programmer-creativity-boost/

Mine Kafon

Landmine Detonator

Design Choices:

• low cost
• wind-powered
• strong enough to set off land mines

Mine Kafon

Omni Crawler

Omni-directional mobile robot.

Another innovation on the mechanical design side.

Lately, I've been berating myself for not paying more attention to the art of design. Throughout the undergrad ece degree, I've been focusing on understanding, interpretation, and problem solving - all of which are useful skills. However, one major aspect that I didn't pay attention to is design, where there are no right answers, and that is where I've struggled. The hardest classes for me have been analog circuit design, circuit board and layout design, and mechanical/enclosure design. I can't even imagine where to start with industrial/communication design.

Design is like a NP-complete problem: easy to solve but hard to optimize.

Everything's interdisciplinary!

GreenThumb PCB

2/27/13
First full schematic/board design from scratch. Its purpose is to monitor humidity and temperature data and record that information for data collection. Data will be downloadable so that I can analyze and store them on an external computer. The purpose of this PCB is to help me identify ideal places to grow plants, because one of my future hobbies will be to grow my own vegetables.

Schematic

Board layout

3/31/2013

My printed PCB! There is a yellow jumper wire near the push button because I forgot to connect the positive terminal of the battery to VCC for the rest of the circuit. Silly mistake! The white enclosure is a case I made using a Solidoodle 3D printer. I designed the CAD by measuring the dimensions of the PCB, drawing the model in Solidworks, exporting to .STL (stereolithography format) files, generating the G-code using the 3D printing software Repetier in conjunction with Slic3r, and then printing the enclosure.

The guide I generally followed to set up Repetier:

http://solidoodletips.wordpress.com/2012/08/22/setting-up-repetier-host/

3D printer model: Solidoodle

plastic type: PLA or ABS (not sure, need to check 4/1/13)

plastic diameter: .065 in

Home screen for Repetier.

Printer settings. Make sure they match your specific printer.

Imported .STL file. 

Visualization settings for the GUI.

Positioning and different angle view of the 

Interface is similar to that of Solidworks. 

Slic3r settings. Used to generate the g-code.

G-code describing how the object will be printed. The instructions tell the printer what operations to perform.

Monitoring temperature. Don't get burned.

Waiting...

Done!

In the middle, I left for a while and when I came back, the light in the printer had gone off and I wasn't sure why. Turns out, someone had turned off the power strip when I was away, and I hadn't noticed. When things are off, it’s usually because they are UNPOWERED. MAKE SURE THINGS ARE ON!!

When printing, it's always better to align your object in the "strong direction". The plane that experiences the most stress should be in the same plane as each layer, in order to make the object harder to break. 3D printing isn't quite ready and cheap-enough to be a staple household item at the moment, but it will be in a couple years when the resolution of the material gets finer and when the printer has a wider variety of materials to choose from!

With this machine, it's important to monitor the printer as its running. The spool of material snapped in the middle of my first print, and I had to stop the machine, feed the spool back into the dispenser, extrude the broken off material, and restart the printing (like taking the broken lead out of a pencil).

It would also be nice to be able to print around materials. I had to cut a corner off my enclosure because I had no way to fit the mini-usb charger port into the device had I left a part of the corner.

I was surprised at the total time of printing - less than 10 minutes for 42 layers. The printer's algorithm was very strange though; it was not a raster scan, although it's likely the user can change that setting. The printer itself is rather simple - stepper motors, lead screws, and timing belts were used to make the plotter. 

The most important lesson that I learned is that all of these types of equipment have many similarities in their technique. But, when switching between machines, there will always be a small learning curve to master the individual nuances of a specific machine.

Code for the device coming soon!

Maximum Power Transfer Theorem

Maximum efficiency != maximum power transfer.

http://en.wikipedia.org/wiki/Maximum_power_transfer_theorem

personal productivity/efficiency ~ maximum power transfer theorem

Sci: Spring Terminal

https://www.sparkfun.com/products/8077

Have one of these on a board for class, but the springs are harder to push down. Works by pressing the spring-loaded button down, sticking a wire in, and releasing the spring. The connection will be clamped down to the metal by the force from the spring. Really useful for prototyping connections that require frequent swapping of sensors/actuators, but the component is really big and extrudes far off the board, so not recommended for pcbs where you know what components you want ahead of time.

Obs: Underestimating electrons in reality

Charge accumulates on an object due to friction, and can be quantified given the contact action as well as the material types. As long as a charged object doesn't touch ground in a vacuum, it would theoretically be able to acquire an infinite amount of charge. In reality, there is a breakdown of air that occurs when something has too much charge, which results in an electric arc.

The movement of charge, current, is what kills you - high power results in heat dissipation which can burn you. In addition, amperes passing through your body can disrupt your heartbeat and other electrical pathways in your body.

Van de Graaf generator revisited:
I was confused why we can touch a Van de Graaf generator and not get killed when we next contact ground. It turns out that air is more conducive than I gave it credit for. After touching the generator, you will discharge fast enough to not sustain injuries before you reach the ground.

Sci: Pulse Jet Jar

1/26/2013

Drilled hole in top of jar.
Fuel: Heet antifreeze.
Placed in bowl of snow/water for cooling.
Shattered one jar.
Accompanied by Ren.

Obs: Screw Theory and Your Shower Drain

1/26/2013

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis? 
Sheldon: Screwed.

-Big Bang Theory

Last week in my Kinematics, Dynamics, and Controls class, we began to quantify screw motions - translating while rotating. 

These motions are the vortexes that we see when we flush a toilet, or when we remove the plug after a bath. The rotational forces can be attributed to the coriolis effect, while the translation forces are due to gravity. 

This reminds me of the whirlpool science project done by taping together two soda bottles and inducing a vortex by spinning it circularly:

Update: this is probably not true. The Coriolis forces are negligible compared to the geometry of the toilet/sink. But they're there!

Ponder: Irrational Numbers in Irrational Bases

1/26/2013

Irrational numbers are rational in irrational bases.
Example: π₁₀ = 10_π

Obs: Gyroscopes in Nature

1/26/2013

I was first introduced to the connection between linear algebra and gyroscopes in Robot Kinematics and Dynamics class, when Dave the TA mentioned gimbal lock. A gimbal is a mechanical device that functions as a gyroscope, with each axis describing an Euler angle. The problem with Euler angles is singular representations, as seen below, where a degree of freedom can be lost. A linear algebra interpretation is two Euler angle mappings to one orientation, meaning there is no unique inverse (and thus a singularity). 

  ------->  

This phenomenon is really dangerous in planes because the pilot can lose information about his orientation, like in Apollo 11 where the spaceship did not have any prevention measures in place for gimbal lock. Fortunately, the brilliant astronauts-turned-astronomers were able to re-calibrate their gimbals using the stars as reference. 

Gimbal lock can be resolved using two gimbals offset in both position and orientation, in which the number of gimbal lock cases should be reduced dramatically, or by adding a fourth dimension to the gimbal.

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Recently, I've begun to notice the ubiquity of gyroscopes in nature. In Metin's bio-inspired robotics, I learned about mosquito halteres, and two days ago we talked about the vestibular system in Richard's psychology of music class. 

A haltere is an organ in mosquitoes that functions as a gyroscope, shown below:

I don't know how accurate this entomological sketch is, but I would imagine that the offset in the halteres is more than just a coincidence - it's probably to prevent gimbal lock! I would suspect that there's also an offset in the haltere orientation, as well as an offset in position in the axis going into this blog. 

Humans also have built-in gyroscopes - the anterior canal, posterior canal, and horizontal canal:

You can kind of see it in the picture - the canals seem to form an orthogonal basis.

I bet that the sets of canals are slightly offset in angle/position in both ears to avoid gimbal lock, just like in planes and mosquitoes, and that balancing issues in people stem from problems with the orientation and position of their three canals! So, I hypothesize that there may exist a surgery that could repair equilibrioception in people. 

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This observation really sheds light for me on the value of interdisciplinary information use. 

Pictures from wikipedia.

Lifehack: Cleaning Up My File Directory

1/8/2013

I finally got around to cleaning my computer's file directory. It was a huge mess, I basically threw everything onto the desktop. I've decided to group files into the following categories:

• Tools
• Exercise
• Resume
• Projects
• Books Currently Reading
• Website
• Notes
• Travel
• Sheet Music
• any current projects

I also had a bad habit of hoarding tabs, but finally realized that information overload is not only bad for my mind, it's unfeasible to read through such a large subset of the internet in reasonable time. Although I have gotten better this past semester, as part of my New Year's resolutions, I plan to stop saving up so many tabs once and for all. More on resolutions in a later post. 

Sustainable House Ideas

1/8/2013

This post will be used to keep track of ideas I have for my house. In the future, I'd like to have the following:

• library
• electronics lab bench
• plant greenhouse
• metal/wood workshop
• solar panels on roof

Sci: Matlab Carriage Return for Single Line Printing

1/7/2013

For smoother feedback in the user interface while loading files or loading something, you might want to overwrite your loading or status bar instead of printing it on a new line. Unfortunately, because of the linearity of stdio in most computers, there's no simple print command (that I know of...) that will do this.

In MATLAB, instead of carriage return, we actually use \b to delete previously printed characters outputted by fprintf. However, in python, you should be able to use \r to obtain the same effect.

Download the demo.

Food: Fontina Grill

12/29/2012

Located in Rockville, Maryland. 

Served from 11a to 130p, the lunch buffet menu included a light pizza, cheese ravioli, meatballs, and steak/mushroom. My favorite was the all-you-can-eat mussels. Would definitely go again. 

http://www.fontinagrille.com/lunch.html