Đánh giá nhanh màn hình LCD Dell S2740L: 27", IPS, đèn nền LED Full HD, giá 8,25 triệu

Hiện nay, màn hình LCD gần như đã hoàn toàn thay thế được công nghệ màn hình CRT cũ, bởi những ưu điểm vượt trội mà nó mang lại, như kích thước lớn hơn trong khi lại gọn nhẹ hơn, màu sắc tươi sáng và đặc biệt là ít tốn điện hơn nhiều lần.

Kết quả kinh doanh Quý 3 của Dell: lợi nhuận đạt 475 triệu USD, giảm 47%

Mới đây Dell đã công bố kết quả hoạt động kinh doanh Quý 3/2012 của mình. Theo đó, lợi nhuận trong 3 tháng vừa qua của hãng đạt 475 triệu USD, giảm 47%

Windows Phone 7.8 đã hoàn chỉnh, có thể được phân phối trong vài ngày hoặc vài tuần tới

Nokia và Microsoft vừa tổ chức một sự kiện dành cho các lập trình viên tại Singapore vào ngày 17/11 vừa qua, trong đó nhất mạnh đến việc phát triển phần mềm cho Windows Phone 8.

Thursday, 26 November 2009

New Haven Holiday Maker Meetup

turkey

Hope everyone had a happy Thanksgiving! Just a quick reminder that the Eli Whitney Museum will be hosting the New Haven Holiday Maker Meetup this coming Tuesday.

What: New Haven Maker Meetup, Christmas Edition
When: Tuesday, December 1, 7:00 pm (note the earlier start time)

Where:

Eli Whitney Museum (directions)
915 Whitney Avenue
Hamden, CT 06517
(203) 777-1833
How Much: Free
RSVP (preferred): kl@eliwhitney.org

Mike and I will bring down some holiday themed projects (the turkey may be a little greasy), and the Museum will have the A.C. Gilbert trains running, along with some other very neat demonstrations that I’m quite excited about.

Thanks to everyone who’s already emailed me – jhuynh at gmail, and I look forward to catching up and seeing everyone (and some cool projects) there!

CIMG8619

Wednesday, 25 November 2009

A walk down calculator lane

I'm at my parent's house, in Connecticut. Which is odd for several reasons. Mostly, it's odd because it means I sleep in my old bed, in my old room, which I haven't done for a long time. But otherwise, it's odd because I get to dig through all my old boxes of gadgets and electronics projects. I did, and I found my first hardware hacking project ever, an overclocked TI82.


Now I have to say up front: I did this in middle school, so I did *not* know how to read schematics yet. Instead, I only knew how to follow tutorials, and that's how I slowly taught myself electronics. This was my first major undertaking.

I followed some great instructions online, which are actually still hosted online! This was perhaps the most pivotal and inspirational tutorial I've ever followed, because it was the first time I'd ever used a soldering iron. In some ways, I credit Mr. Rich with motivating me to get interested in hardware hacking to begin with. So whoever you are, Rich, thanks a lot!

Speaking of Kevin Bacon, I learned engineering because of Mr. Rich, who taught my over the internet how to overclock my TI82, which led me down a long road to learning engineering, but! Rich apparently knows the guys at Solarbotics, who are doing Arduino stuff too, and Solarbotics is the company by Mr. Mark Tilden, who does BEAM robotics, and who used to be at Los Alamos, which is where I was visiting just a couple weeks ago. Insert Twighlight Zone music...

But I digress. I had two TI82 calculators throughout middle school and high school. Who wouldn't?


One had an Apple logo on one side, and a Linux logo on the other. Brand loyalty starts from an early age, apparently :-)

Naturally, I only overclocked one of them, because the acceleration ruined the graphing capabilities (the pixels plotted too quickly and overwhelmed the refresh rate of the display). So I was *that* kid in middle school, and PROUD OF IT, who walked around with 2 calculators. One overclocked for algebra and simple TI programs, and another for graphing. I credit my math teachers, who let me use both calculators on all my math tests!

What good is an overclocked calculator if it doesn't have a fan? Exactly. Does it need a fan? No. Does it look 10000 times cooler with a fan? Yes. Am I embarassed about this, years afterwards? No. Two words: middle. school.

So naturally, I put a fan on the back, and wired it into the battery pack. That also meant I needed to put the battery pack on the outside in a special holder...


I should note, that however cool I thought this looked at the time, I can safely say now, this did not net in any additional dates with girls.

Flash forward...

I thought to myself, why not line up all the big hardware projects, left to right, starting with the first TI-82 calculator I ever had, then moving on to the first real hardware hacking undertaking overclocking project, then on to the Arduino, the OpenBerry, the Portable MegaPalm, and of course the IXM. My current project is to the right of the IXM, but I'm not telling anyone what it is until January ... it's top secret, and only a few people in the world know about it. Not even the government agencies know ... hehe. :-)



Now, of course, I'm not in middle school any more, but I still have a thing for carrying around two calculators:


That's a CFX-200 (of course!) and the powerhouse HP-17BII+, which is the most under-rated calculator in the history of calculators. And believe me, I collect calculators, and I have used almost every calculator known to mankind. The secret little trick that no one but me knows is that the HP 17BII+ has this this feature called SOLVE, which is a one-key equation solver, which is fully programmable. BUT! The calculator itself looks understated... it just looks like a normal calculator, so no one thinks you're a super nerd just for busting out a graphing calculator in a relaxed meeting, but then you're like BAM-I-can-factor-primes-instantly-and-reduce-multi-variable-equations-instantly. And then everyone looks at you like you just did it in your head, and you're like, "what, me? no... this is nothing, if you think that's impressive, you should see my overclocked calculator collection from middle school."

:-)

Thursday, 12 November 2009

4 Operating Systems for the Arduino

I was working in the lab, late one night, when my eyes behold an eerie sight... Yes, Halloween is a long time ago, but that stupid song is still stuck in my head. I miss Halloween. I never got to post up pictures of my skeleton running off IXM's. :-)

Anyway, I was browsing the Arduino forums and saw this cool post about DuinOS, a real-time embedded "operating system" for the Arduino.


DuinOS by RobotGroup

It's a simple little realtime OS (RTOS) built by the guys at RobotGroup (hello!), and can be downloaded here. It's meant to have a simple function scheduler, implementing a basic form of multitasking (not quite multithreading, but something like round-robin scheduling I think). That let's someone code multiple functions at a time, that get executed in turn, so that a single Arduino could be executing multiple types of "apps" or "sketches" at the same time.

Well, that's something of a stretch, but it's getting there... we won't get into context switching an RAM page swapping just yet :-)

So then that got me thinking, why not write up the other "OS's" out there for the Arduino platform. So here are the other 3 Arduino operating systems I'm aware of...


Pyxis OS by ArduinoWill

This is a graphical OS built on top of the Arduino and TouchShield platform, and is written by ArduinoWill (aka Thom). Thom is ridiculous, and extremely talented at coding. He has been prototyping some of the craziest stuff I've seen on the MegaPalm kit, DOSonChip, and the TouchShield Slide.

Ok. Here's a video of Pyxis OS in operation, which is quite ridiculous:



ArduinoWill also figured out a crazy hack to implement portrait and landscape mode...



And I'm not even going to mention the Super Mario level port:



Pretty insane... 12 fps. 0x000C. 00000110b frames per second. I'm still trying to figure out how you did this...

ArduinoMacOS by Mark

Mark managed to port a few apps to the Slide, including... um, I don't know... a GPS, Tic Tac Toe, Tetris, a Calculator, Oscilloscope, Breakout, The Matrix Screensaver, and a Canvas Drawing program. And the Control Panel. And Hex editor. And a Graphics Demo. And an analog Pin Visualizer.

And it's all zipped up over at the Open Source App Store here.


I wish I still had screen shots... I've searched my hard drive inside out, but instead, I just have the source code :-( EDIT: I finally found some pictures, and uploaded them above...


TaOS by Ziplock

Here's another lite-weight operating system, this time built by Ziplock. It's a simple embedded GUI that focuses on assigned blocks of code to little squares. In essence, it's the epitome of a miniature, lightweight script execution OS. Applications are like mini-apps.

If every operating system were written with this little overheard, I'd be running Quake on an 8 bit Motorola 6800 written in assembler...

Anyway, I digress, but the code for TaOS is all available over here.

Saturday, 7 November 2009

What's The Best Instant Coffee for Hacking?




Chris and I just spent the last couple weeks completely strung out coding and hacking the IDE. There were a number of problems, but they all stemmed from two simple issues that could be summed up in one word: "suck".

1) Apple deciding to modify the binary java application launcher in preparation for 64 bit java compatibility (which broke the Aardvark IDE), and

2) Windows 7 sucking. Billy G. locked down certain folders, changing the way programs have to deal with temp files (which also broke the Aardvark IDE)

Anyway, Chris wrote a blog about how we solved the issues technically speaking. But this is a differenty kind of blog. This is the one that describes how we solved it biochemically speaking. With coffee, of course.

We drank a lot of coffee, especially late at night, and when Starbucks or the local joints are usually way past closed. So I figured it was a great excuse to do some double-blind taste tests of the various instant coffees I could find at the grocery stores around me.

Here are the five types we taste tested, from left to right, Maxwell house, Medaglia D'oro, Starbucks Bold Via, Starbucks Columbian Via, and Mount Hagen. You pretty much have to live in a bubble not to have seen all the advertisements for Starbucks Vias recently, so this was also Chris and my attempt to cut through all the marketing B.S. out there...


Naturally, we took out a piece of paper to document the experiment:


The Via's needed scissors to open, which sucks. Everything else was easy to use, but needed a spoon, which is a more readily available "kitchen" tool as far as I'm concerned. On the other hand, the lab space always has scissors lying around, so I guess it all depends on where you fix your coffee.


Here's a close-up of the different looks of the instant coffee. Mount Hagen sort of looked like bacon bits, and perhaps as a result, looked the most appetizing. Medaglia was sandier, while the others were more like little piles of dirt.


Here's the full get-up. I followed the recipe marked on the label in every case, down to the amount of grinds, and water.


Here's me pouring out the microwaved water into one of the cups:


And this is what all the glasses look like when they're filled:


And after I stirred each glass:

One thing to note is that the Mount Hagen is the only one with foamy bubbles at the top. This is weird. It would have been fine if I'd put milk in there, and stirred it up. But I didn't. It just somehow likes to keep its foam. For some reason, this foam stayed there the whole time. Not good, not bad, just different.

To clear our pallates in between sampling, we used Diet Coke. Why? Because it's another liquid that commonly makes it's way around the lab, and is often the chaser Chris and I use when drinking coffee. There's something satisfying about drinking a hot cup of coffee, then a cold glass of diet coke, then another hot cup of coffee, then about cold glass of diet coke.

Hi, my name is Matt, and I have a caffeine problem.


While we drank, we kept notes on the first imrepssions, tools needed, time to prep, amount of water needed, smell test, taste test, and even what each type tasted like after waiting a while. The rationale went like this: a lot of times, I make a couple cups of coffee at a time, pour them out, and bring them from the kitchen into the lab. Inevitably, one of the glasses gets cold. Drinking cold coffee is a fact of life in a lab :)

Finally, we ranked each of the 5 in terms of total experience, and provided summary notes.


I even typed it up:


The bottom line

If you can get over the weird foaminess, the Mount Hagen is the best tasting coffee, hands down. The Italian Roast Bold Via is the next best taste, but you have to drink it all quickly, because it starts to taste a little stale after sitting around. The Columbian Via holds its flavor better, but that's because that flavor is bland. Maxwell House has a chemical, synthetic taste in my opinion, kind of like that smell you get when you drive on I-95 through New Jersey, and you drive past that big chemical refinery and the air smells like pancakes which is normally good but you start holding your breath because you know it's not really pancakes, it's actually acetyln glycol esther mercury fumes. Medaglia D'oro was 3 European ounces of just plain horrible - they had me at the smell - which is tart and sour and nasty and frankly has no business belonging in any cup I'm drinking.

So in conclusion:

  1. Best - Mount Hagen if you can live with the weird foam
  2. Runner up - Italian Roast Via
  3. So so - Columbian Via
  4. Eh - Maxwell House
  5. Get out - Medaglia D'oro

Aardvark 0.8.36 Released

This is the next installment of the Aardvark 0.8.x series. Notable new features include:
  • New Library menu that's board friendly
  • New Library reference docs
  • Larger reference panel
  • The library example list auto repopulates when the board changes.
  • Added JeeNodes library (Ports, RF12)
  • Arduino Duemillanove upload bug fixed, thanks Fred!
  • Misc startup fixes
Download @ Illuminatolabs

I've added a Library Menu that dynamically changes with each different board. Here, we see the standard libraries for the Arduino family of boards:



I've also included new reference docs for the Libraries, which load up a library is pulled into the sketch. Below, we see a quick reference for the AFSoftSerial library:



Tip: A quick way to show the reference panel is to click Help->Reference.

Thanks for all the code contributions that made this all come together.

Monday, 2 November 2009

New Haven Maker Meetup, Christmas Edition

I’ve been getting a lot of emails about the next New Haven Maker Meetup, so it must be about that time again.

The Eli Whitney will be hosting the second Maker Meetup in the first week of December, so Christmas themes are welcome, though Thanksgiving projects are certainly interesting too. Actually, I wouldn’t mind seeing some neat Halloween costumes or setups either, but that’s just me. 

What: New Haven Maker Meetup, Christmas Edition
When: Tuesday, December 1, 7:30 pm - 9:30 pm

Where:

Eli Whitney Museum (directions)
915 Whitney Avenue
Hamden, CT 06517
(203) 777-1833

How Much: Free
RSVP (preferred): kl@eliwhitney.org

Here’s a couple projects Mike, Chris and Matt did for the holidays last year that might make another appearance:

The 8-bit embedded TurkeyShield

This year, maybe a 32-bit embedded turkey with the IXM?

Mike’s Christmas Tree Upgrade

And it’s always fun to make lights blink in cool new ways :-)

Give me a shout if you’d like me to send a reminder email, or if there’s a project Mike and I should bring to this meetup – jhuynh at gmail. Hope to see you there!