Character LCD Screen Add-on For Android Devices

July 12, 2011 by Mike Szczys 10 Comments

Here’s an Android accessory project that adds a secondary LCD display. It utilizes the Android Open Accessory Development Kit standard to connect the 16×2 character LCD as a USB device. It pairs an app on the phone which runs transparently with firmware for the ATmega2560-based Arduino compatible board you see to the left. The app launches as soon as the auxiliary hardware is connected and is responsible for determining which lines of text are pushed out to the LCD. The example code displays the current time on the top line, and scrolls incoming text messages as they are received.

This is a good way to get your feet wet with the ADK hardware. We’ve already seen it used for larger displays like this LED marquee, but this smaller test project doesn’t require much hardware setup. Chances are you either already have an Arduino and character LCD on hand, or can easily borrow which makes this an easy weekend project.

One note on that Arduino compatible board; it’s called a Freakduino ADK but we couldn’t figure out if it’s a Freak Labs product or not. If you have some insight about that, please leave a comment.

FPGA Generated SPDIF Output

July 12, 2011 by Mike Szczys 13 Comments

[Mike Field] just finished implementing SPDIF generation on an FPGA. SPDIF is an industry standard for transmitting digital audio signals; the acronym stands for Sony/Philips Digital Interconnect Format. It’s been around for more than a decade and since it’s found on most home-audio equipment, building an SPDIF output into your projects may be quite a desirable feature. [Mike] mentions several ideas for this functionality like building high-end test equipment, or providing a high-quality output for electronic instruments.

He first jumped into analyzing the specification in order to determine the hardware requirements. Due to some issues with jitter, he found it necessary to use a 100 MHz clock signal. This pushes the jitter down to +/- 5ns of jitter, which he concedes may raise the hackles of audio purists, but does satisfy the published standard. Output requires just one pin of the FPGA and the five components seen above. A hex inverter (74HC04) voltage divider, capacitor, and RCA connector transmit the 0.5V signal to your audio-receiver of choice. Of course, since TOSLINK fiber optic connectors use the same protocol, you could redesign the output and make this an optical connection.

FabLab Helps The Developing World Set Up Long-distance Wireless Ethernet

July 12, 2011 by Mike Szczys 29 Comments

The wooden frame seen above hosts a parabolic reflector making up one side of a wireless network link. This is a Fab Lab project called FabFi which uses common networking hardware to setup long-distance wireless Ethernet connections. It’s a bit hard to tell in the image above, but the reflector focuses radio waves on the antennae of a router we’re quite familiar with, the Linksys WRT54G. It’s held upside-down in an enclosure meant to protect it from the elements. The node above manages to complete a connection spanning 2.41 miles!

One of the core values of the project is to develop hardware that is easy to build with limited resources, then to make that knowledge freely available. Anyone who has the ability to download and print out the 2D design file can build a reflector for themselves. As we’ve seen in other projects, paper stencils and hand tools can handle this job with no need for a laser-cutter (which was used for the prototype). WRT54G routers are inexpensive and the project uses the open source firmware OpenWRT. They can be run from 12VDC power which means a car battery works when mains power is not an option. The system has been running in Afghanistan for two years and hardware failure is still in the low single-digits.

[Thanks das_coach]

Zzstructure Emulator

July 12, 2011 by Brian Benchoff 14 Comments

[John Ohno] has been working on a zzstructure operating system written C since January. [John] realizes not many people know what a zzstructure is, so he posted a demo of his project. [John] has also put all the code online.

A zzstructure is both a hypertext and operating system unlike anything we have today. You could say that when it was first conceived in 1960 it was 100 years ahead of its time. [John]’s implementation of zzstructures operates on a 256-dimension grid and functions a lot like a multidimensional forum thread. Although that’s a lot to wrap your head around, it can probably best be explained by [Ted Nelson], the creator of zzstructures.

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Wearable Video Coat

July 12, 2011 by Brian Benchoff 13 Comments

[David Forbes] is no stranger to the weird and esoteric, so he created a color LED TV built into a lab coat. He plans on bringing it to Burning Man next month.

The RGB LEDs are mounted narrow flex boards, providing a 160×120 pixel NTSC display. Video processing is taken care of by an Xilinx FPGA that takes the YCrCb video feed from a video iPod and converts it into four separate RGB streams for the front, back, and the two sides. The requisite controls for brightness and color are on the shoulders.

Of course, the build wouldn’t be over-the-top without the ability to plug a Nintendo into a lab coat, so there’s an NTSC input on an RCA jack. Everything is powered by two 11.1 V, 5Ah radio-control LiPo battery packs that should power this for a while.

Check out a video of the LED lab coat below.

[youtube=http://www.youtube.com/watch?v=jtSm8Oom2n4&w=470]

One-click Unbrick For Samsung Phones

July 12, 2011 by Mike Szczys 20 Comments

[Adam Outler] has been pretty heavy into mobile device hacking lately. The biggest problem with that field is recovering from back flashes or development firmware glitches. In many cases you can use a JTAG programmer to reflash stock firmware to resurrect a handset. Unfortunately you’ll be hard pressed to find a phone that comes with a JTAG header, and soldering to the microelectronic boards is not for the faint of heart.

But a solution is here, [Adam] pulled together a wide set of resources to create a package to unbrick Samsung phones. Now we’re sure that there’s more than a handful of people who would argue that a bad firmware flash that can be fixed this way means that the phone wasn’t actually “bricked” in the first place. But what we see is one more barrier torn down between being a hardware user and becoming a hardware hacker. You’re much more likely to get in there and get your hands dirty if you know that you’ll be able to undo your mistakes and reclaim you precious pocket hardware. See just how easy it is in the video after the break.

Continue reading “One-click Unbrick For Samsung Phones” →

Re-manufacturing Inkjet Cartridges For 3d Printing

July 12, 2011 by Mike Szczys 6 Comments

[Nullset] uses inkjet printer technology for his 3D printing needs. We usually think of hot-plastic printing like the RepRap or Makerbot when we hear about rapid prototyping, but this setup uses a liquid bonding agent to turn powder into a solid structure. Standard inkjet cartridges can be used to precisely place the bonding agent, but it’s hard on the heads and you have to replace them often. [Nullset] is getting pretty good at it, and decided to write a tutorial on the modifications necessary to print with bonding liquid.

At its core, the method injects binder into the cartridge through one port while using a second for drainage. [Nullset] found that the needle fittings used to inflate a basketball work great for this. He drills a couple of holes that the threaded end of the needles fit into. That connection is sealed with some epoxy, and the tubing that delivers the binder is zip-tied to the needles. A bit of purging is necessary to get rid of any old ink, but after the initial flush you’ll be up and running pretty quickly. He figures the whole process can be one in around 10 minutes once you get the hang of it.