Touring Component Markets In Shenzhen

September 28, 2013 by 34 Comments

touring-component-markets-in-shenzhen

[Al] recently returned from a trip to China. While there he toured some of the component markets in Shenzhen, the electronics assembly epicenter of the world. While he doesn’t focus too closely on what is actually being sold there, we found his description of the markets themselves and other notable attractions around the area quite interesting.

Shenzhen is different from some of the other component wonderlands we’ve heard about ([Ian Lesnet’s] tour of Akihabara in Japan comes to mind). First of all it may be a bit more difficult to get there. US Citizens need a Visa to enter China, and must fly to Hong Kong and take a ferry to the mainland. [Al] reports that the traffic is horrendous and rush-hour can turn a ten mile ride that usually takes ninety minutes into a three hour tour… a three hour tour!

The side affect of the market being out of the way is that the prices aren’t as inflated as they may be in more geek-tourist-friendly locations. That being said it also sounds like the vendors are interested in selling you a few thousand units rather than a single component. Follow the link at the top for the market tour, a stop at Seeed Studios (who will apparently sell you a map of the best markets to visit), and the rest of the attractions that [Al] encountered.

Breadboard Tetris Is Wire Artwork

September 28, 2013 by 13 Comments

RGB-module-breadboard-tetris

Look closely at the colored pixels on this pair of 8×8 RGB LED modules and you’ll be able to pick out some of the familiar shapes of Tetris pieces. It’s impressive that [Jianan Li] built his own color Tetris including the theme music, but look at this breadboard! The layout of his circuit is as equally impressive as the code he wrote to get the game up and running. It takes a fair amount of planning to get a circuit of this complexity to fit in the space he used, right?

There are two microcontrollers at work, each running the Arduino bootloader. The main chip is an ATmega328 which is responsible for monitoring the buttons and controlling game play. The other is an ATmega85. The eight pin chip listens to it’s bigger brother, playing the theme song when the game starts, and pausing or resuming to match the user input So is the next stop for this project playing Tetris on the side of a building?

Don’t miss the demo video after the break. We’ve also rolled in a video of his Arduino-based piano. It’s built on a breadboard that’s nearly as impressive as this. But what delights us is his skill at playing Pokemon themes on the two-octave tactile switch keyboard. Obviously those piano lessons his parents shelled out for really paid off!

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Custom E-Cruiser Has Features For Disabled Rider

September 28, 2013 by 16 Comments

e-crusier

As [AussieJester] noted in the first page of his build log, most people’s idea of a “custom-made” electric bicycle involves strapping some electronics and a hub motor onto any off-the-shelf bike. He needed a bigger challenge, so he fabricated his own frame to build a stylish electric cruiser. This bike has a 2-speed transmission and a massive Turnigy 80-100 brushless outrunner motor, which pushes out a top speed of 45mph.

You may have noticed what look like training wheels in the picture above, and you’d be half-correct. [AussieJester] is a paraplegic, and needed to guarantee some stability both when transferring from his wheelchair and when coming to a stop. The best feature of this bike, however, is that these small wheels are retractable. A linear actuator lowers them for slower speeds and for mounting/dismounting, but picks them back off the ground once you are up to speed, maintaining a true 2-wheeled experience.

Stick around for a couple of videos after the break: a first-person POV showing just how quick this bike can move, and a demonstration of the actuators. Then check out another EV pioneer in the world of skateboarding.

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CD-ROM POV Clock

September 28, 2013 by 12 Comments

clock

[Kyle] wanted to try something new. A Persistence of Vision Clock using a CD-ROM drive.

We have covered lots of POV Clocks that make use of hard drives, but we think this is the first time we have seen a CD-ROM drive used instead. [Kyle] points out that CD-ROM drives are typically much quieter than hard drives, which is the main reason he chose the CD-ROM route.

At the heart of this project is a good old ATMEGA168 and an RGB LED strip for the lights. To measure and maintain the rotational speed of the clock [Kyle] used an IR photodiode that detects a reference mark on the disc. An elegant build of a classic POV Clock, with a new twist!

The cool thing about this project is he did not actually use the CD-ROM drive like you think he would — he chucked the spindle motor and instead is spinning the disk using the tray ejection motor! He did this so he could control the motor by PWM straight off the microcontroller, whereas the spindle motor would require an IC and a varying control signal with specific voltage amplitudes.

He also experimented with different backgrounds and background lighting, which you can see in the video after the break!

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DIY Metal Detector

September 28, 2013 by 15 Comments

Looking for a light project to teach young hackers some very basic electronics? Here’s a quick and easy weekend project, a simple metal detector!

We all know 555 timers are very useful and pop up in a wide range of projects, but did you know a metal detector is one of them? [vonPongrac] stumbled upon this handy guide, a free eBook on 50 555 Circuits, which contains many cool project ideas, including a simple metal detector circuit. It’s a very basic concept that uses a coil of copper wire as a home-made choke — when metal or a magnet comes near the coil, it varies the output frequency, and the 555 timer in turn, varies the output sound, alerting you of the presence of something metal nearby.

After the break there’s a video of it during its testing phases. If you don’t have a 555 on hand (tisk tisk) but still want to have some treasure hunting fun you can also build one based on an Arduino.

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Making QR Codes In Google Docs

September 28, 2013 by 6 Comments

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[Jordi] sent us this great tip on how to generate QR codes inside Google Docs. This can be super handy if you ever need to make a lot of them at one time, plus they update on the fly!

In his example he set up the code to create vCards so he could transfer contacts to his phone quickly and easily. The code pulls in a Google API QR generator and provides you with a QR code as an image! The following is his code, which can be easily modified to suit your needs:

=image("https://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=BEGIN:VCARD%0AN:" & A2 & "%20" & B2 & "%0ATEL;CELL:" & C2 & "%0AEMAIL:" & D2 & "%0AEND:VCARD")

Or if you just want the bare bones:

=image("https://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=<strong>YOUR CELL</strong>")

And if you need a full walkthrough, there is a video after the break. Those wanting to tinker around with more QR code hijinks will enjoy forming images from QR codes and milling QR codes into your copper layers.

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Mechanical Typewriter Types Your Tweets!

September 27, 2013 by 17 Comments

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While we weren’t able to visit the Toronto Maker Faire this past weekend, a friend let us know about this great hack. A mechanized typewriter that types out tweets directed at the maker, @mschwanzer!

[Michael Schwanzer] has a few blog posts outlining the build, but the first part of this news article and accompanying video explain it quite nicely. The printer-typewriter features an array of solenoids that are controlled by an Arduino using shift registers. A Raspberry Pi collects the information from Twitter and then parses the data to the Arduino for typing. A simple concept, but a complex and relatively expensive build.

During the fair, people could have their own tweets printed and streamed on this site. You can still see it in action though, just check out the video after the break! Continue reading “Mechanical Typewriter Types Your Tweets!” →