[ch00ftech] Visits A Shenzhen Market

September 17, 2012 by Eric Evenchick 33 Comments

On a business trip, [ch00ftech] visited a Shenzhen electronics market and documented the trip. Some of the attractions included multiple Apple stores of questionable authenticity, stores selling PC components with no manuals, drivers, or packaging, and a variety of LEDs and lasers.

[ch00ftech] showed off the loot from the trip, including breadboards, perf boards, LED matrices, and an RFID reader all for very low prices. There’s also the Class 4 laser pointer that cost about $120 and has a power output of “between 500 mW and 8000 mW.” Given the 500 mW power restriction on lasers sold in the US, it’s fair to say that this thing should be handled with care. Hopefully the included safety classes actually block the specific wavelength of the laser.

The staff in these stores were very knowledgeable and knew part numbers and inventories by memory. One of the biggest surprises was just how low the prices were. While Radio Shack has started to carry some more parts for hackers, it seems that nothing stateside can compare these Chinese electronics markets.

Switch Mode Breadboard Supply From A PTH08080

September 3, 2012 by Mike Szczys 19 Comments

[Ben] wanted a switch mode power supply for his breadboard. He ordered a PTH08080 module which is made by Texas Instruments. The spec sheet would make it a great choice for him, but he was not happy to learn that the pinout doesn’t conform to the 0.1″ spacing used by solderless breadboards. His solution was to make a breakout adapter from some protoboard.

The PTH08080 can source up to 2.25A. It accepts 4.5-18V input and can output 0.9-5.5V. The best part is the efficiency that a switch mode supply achieves compared to linear regulators. This design adds in two capacitors which are suggested in the application circuit from the datasheet (PDF). Notice that there are two headers on the breakout board. One supplies power and ground to the breadboard. The other gives him a place to connect the adjustment resistor used to select the output voltage. This connects between one pin on the PTH08080 and GND. [Ben] plans to upgrade the design by included a precision trimpot for easy output voltage adjustments.

Hackaday Southwest Tour

July 26, 2012 by Caleb Kraft 20 Comments

Earlier this summer, I took a trip through the southeast of the country. On this trip I was able to visit several hackerspaces and meet some really great people. We started at Squidfoo in Springfield Missouri. Then Moved on to Makers Local 256 in Huntsville Alabama. After that we saw 7hills hackerspace in Rome Georgia as well as Freeside hackerspace in Atlanta Georgia. The final leg of the trip took us to Chatt*Lab in Chattanooga Tennessee and the Hacker Consortium in Nashville.

For this trip, I am taking my family to the Grand Canyon. Well, that’s the part the kids are looking forward to. I’m looking forward to more hackerspaces and fantastic people. If you’re along the route from Springfield Missouri to Flagstaff Arizona, let me know (we’ll be hitting roswell NM on the way back too). We can go a little out of our way, but not hours. I would really love to visit some hackerspaces on this trip and do a video tour. You can comment here or hit me directly at caleb@hackaday.com.

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Making Flex Sensors On The Cheap

June 4, 2012 by Brian Benchoff 17 Comments

When [Michelle] was making a sign language translation glove, she needed a bunch of flex sensors. These flex sensors cost about $10 a pop, meaning her budget for the project was eaten up by these bendy potentiometers. Since then, [Michelle] figured out a great way to make extremely inexpensive bend sensors using anti-static bags and masking tape, allowing her to start her project once again.

The build works by sandwiching Velostat plastic bags – the same electrically conductive bags all your components arrive in – between layers of masking tape. A jumper wires is attached to a strip of Velostat attached to a piece of masking tape. Between two of these anti-static/masking tape assemblies, another piece of Velostat is placed. After laminating all these pieces together, [Michelle] had a primitive yet very functional flexible potentiometer.

After attaching one of these flex sensors to an analog input of her dev board of choice, she had a wonderful and inexpensive flexible sensor. You can check out this sensor in action after the break.

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Printing Anything With A Thermal Receipt Printer

April 15, 2012 by Brian Benchoff 52 Comments

Over the last year, [James] has been a part of a few commercial projects that used a thermal receipt printer as part of the build. Something must have cracked in his mind, because [James] spent a lot of time developing a way to print customized content on receipt printers, connecting these printers to the Internet, and sharing content with other Internet-connected receipt printers. Even [James] doesn’t know why he spent so much time on this project; [James] figured he was bound to find something interesting. We’ve got to commend him for that.

[James] had been aware of the Adafruit Thermal Printer Library, but this library is a little kludgy. Text is the Adafruit Library’s forte, and while graphics and non-ASCII characters are possible they’re certainly not easy to print with the existing libraries. With his current system based on HTML, CSS, and Javascript, [James] has a really easy way to print anything he can put on a webpage on receipt paper.

Getting his receipt printer onto the Internet had its own challenges. After wrangling with the Arduino Ethernet library through the month of February, [James] realized larger prints (about 15cm of paper) would fail inexplicably. To get around this, [James] wrote an HTTP client for the Arduino that would fetch data, put it on the SD card, and then start printing.

Right now, [James]’ project is a polished as anyone could hope. We’re a bit concerned – although we completely understand – that he could get sucked into the black hole of pointless development of receipt printer software so easily. All was not for naught, though; now anyone can make very professional-looking prints on receipt paper very easily.

StorageBot Finds All Your Components, Makes Your Storage Drawers Feel Inadequate

March 18, 2012 by Brian Benchoff 33 Comments

Your experience with making things, building projects, and hacking hardware is directly proportional to the amount of components you have on hand; as our experience grows, so do our space and storage requirements, it seems. [Danh Trinh] must have decades of experience, because his StorageBot robotic parts drawer is as awesomely absurd as it is clever and useful.

At first glance, StorageBot just looks like a bunch of small parts drawers mounted to the wall with LED strips along the top and side. The magic happens when [Danh] walks up to the wall-mounted laptop and commands StorageBot to find a component with his voice. A video is worth a thousand words, so you might as well head to the video for the best description available

To get the StorageBot to listen to his voice, [Danh] downloaded Microsoft’s speech recognition SDK and built a VB app to turn his voice into a location of what drawer contains the part he requested. Once StorageBot finds the row and column of the requested part, a pair of stepper motors behind the wall of parts drawers swing into action. Soon enough, the drawer containing the requested part pops out, and [Danh] can go about his business building more awesome stuff.

Because a few paragraphs can’t convey exactly how cool [Danh]’s StorageBot is, take a look at the videos after the break.

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Reverse Engineering A Nokia LCD

March 8, 2012 by Brian Benchoff 16 Comments

LCD displays taken from old Nokia phones have been a staple of the hardware makers for years now, so we’re very happy to see [Andy] reverse engineering a full color QVGA display so we can move our grayscale projects over to a full-color display.

The screen in a Nokia 2730, 5000, and 7100 cell phone is a wonder of technology – its 18-bit color with a very high-resolution piqued [Andy]’s interest. He bought a second-hand Nokia 2730 off of eBay and started taking it apart. After checking out the schematics for the phone, [Andy] had a few breakout boards made; especially useful since he found a few connectors as well.

With a great deal of Googling, [Andy] found another lost soul who successfully broke into a similar LCD display and discovered it was command-compatible with a Magnachip LCD controller. The only way forward was to send a few of these commands over to the display and watch what happens.

[Andy] managed get pixels drawn on the screen, and found a few interesting features: hardware scrolling is enabled, as is changing between portrait or landscape orientations. From a second-hand phone on eBay, [Andy] now has a very nice QVGA display. We’re calling this a win, but you can judge the video after the break for yourself.

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