Portable Light Box For Small Photography Needs

August 21, 2012 by 6 Comments

[Paulo] needed to photograph small objects on the go. Since you can’t always depend on ambient lighting conditions he built a battery operated light box which is easy to take along on his travels.

We’ve featured portable light tents before, but they still tend to be a bit too bulky for his tastes. He chose to go with a white plastic storage container from Ikea. It’s lightweight, and acts as a diffuser for the light sources. Four strips, each hosting three LEDs, were mounted on the exterior of the container. Half of a PVC pipe protects the boards while providing a way to fasten the strips in place using nuts and bolts. The driver board and batteries find a home inside of a travel container for a bar of soap.

He likes the results, especially when a glossy white piece of paper is used as a top reflector.

Arduino WiFi Shield Available, Costs $85 USD

August 21, 2012 by 35 Comments

Over on the Arduino blog, the release of the official Arduino WiFi shield was just announced. On the spec page for this WiFi shield. we can see this new board isn’t a slouch; it’s powered by a 32-bit ATMega 32UC3 microcontroller, has provisions for WEP and WPA2 encryption, and supports both TCP and UDP with the Arduino WiFi library. It also costs €69/$85/£55 from the Arduino store.

Now that the announcement of the Arduino WiFi shield is over with, we’ll take this opportunity to go through a few other WiFi adapters for the Arduino that don’t cost an arm and a leg.

The WiFly shield – available from Sparkfun – is a WiFi adapter with the same form factor as the ever popular XBee modules. Of course, it’s possible to make your own breakout board; the WiFly only needs a TX, RX, power and ground connection to connect your Arduino project to the Internet.

We’ve seen a few projects use the WiShield from async labs. It’s a WiFi module packaged in the familiar Arduino shield form factor, and costs $55 USD.

For the hardcore hackers out there, you could always get a bare Microchip WiFi module and get it to work with an AVR as [Quinn Dunki] attempted to. In all fairness, [Quinn] was trying to de-Arduinofy the WiFi library; if you’re cool with Arduino code swimming around in your project, this method will probably work.

There’s also the very, very cool Electric Imp. Basically, it’s an SD card with a built-in WiFi module. After configuring the Imp by holding it up to patterns flashing on your smartphone screen, this device serves as a transparent bridge to the magical ‘cloud’ we’ve been hearing about. The Electric Imp was supposed to have been released in late July/early August, and we’ll put a post up when this cool device actually launches.

Of course we’re neglecting the simplest solution to getting WiFi running on an Arduino project: just use a wireless router. Really, all you need is a pair of TX and RX pins and a copy of OpenWRT. Easy, and you probably have the necessary hardware lying around.

We’re missing a few methods of Arduinofying a WiFi connection (or WiFying an Arduino…), but we’ll let our readers finish what we started in the comments.

Building A Resistor Substitution Decade Box

August 21, 2012 by 24 Comments

[George] built an incredibly tidy resistor substitution decade box. These devices feature a pair of connections and a way to select the resistance between the two of them. In [George’s] case it’s a pair of banana jacks and these eight thumbwheel switches.

What you see above is the side of each thumbwheel switch. These are panel mount devices which show one digit with an up and down button to change the setting. As you can see, the PCB for each provides connections to which a set of resistors can be mounted. This is the difficult part which he goes to great lengths to explain.

At this point he’s got the resistor groups for each digit soldered in place, the next step is to stack the switches next to each other and connect them electrically. From there it’s off to a project box in which they will be mounted.

This project does a great job of explaining the assembly process. If you’re interested in the theory behind a substitution box check out this other project.

128-inch Silver Screen For Your Viewing Room

August 21, 2012 by 16 Comments

This huge projection screen fills an odd alcove in [Dodge Boy’s] screening room. He built it himself for under $200. The materials, tools, and techniques make this a possibility for anyone who wants their own projection setup.

The frame is made of pine 1×3 dimensional lumber. To keep the fabric from touching the supports in the center of the frame he added quarter-round trim to around the perimeter. From there he painted it black and went for a test-fit. The bad news is that the drywall is neither perfectly flat, nor parallel/square. He ended up taking the trim off and ripping down one side of the frame. That did the trick and he went on to stretch spandex over the whole thing. The frame hangs from a french cleat on either side of the opening. From what we can tell, the surface is just fabric and not painted as we usually see with these setups.

[Dodge Boy’s] utility room shares the back wall of the screening room. That’s where he stores the HTPC which feeds he project, with an RF remote to control it through the wall.

[via Reddit]

tft-with-arduino

Use A Nokia N82 TFT Panel With Your Arduino

August 21, 2012 by 16 Comments

[Andy] has been hard at work reverse-engineering the Nokia N82 2.4 inch cell phone display for use with an Arduino. As pointed out in the article, this same 2.4 inch display can be found in at least seven other Nokia products, so they are readily available. The panels can be found for as low as 3 pounds (or a little less than 5 dollars) on Ebay.

The results are quite good and can be seen in the videos after the break. The first demo displays a simulated weather report, and the second displays some JPEG images. Although an Arduino Mega was used in this demonstration, a standard Arduino can be used as well. Schematics as well as a bill of materials is included in the article, however if you’d rather just buy a board, he’s selling the rest of what he’s built on a first come first served basis. No word on how many he has in stock though!
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Lite Brites Fade, But LED Clocks Are Forever

August 21, 2012 by 7 Comments

litebrite-clock

Ahh, the Lite Brite.

What could be more fun than pushing dozens of little plastic pegs through a piece of black paper in order to create a pixelated, though colorful image? Well, I can think of quite a few things more engaging than that, and luckily so can [Lonnie Honeycutt] over at MeanPC.

While contemplating what to build with a pile of LEDs, his daughter came into the room with her portable Lite Brite. He thought that the pegs she was using looked awfully similar to the LEDs on his desk, so he did some test fitting and was surprised to see that they fit almost perfectly.

[Lonnie] thought that the toy would make an excellent clock, and his daughter happily agreed to let Dad do some tinkering. A few hours, an Arduino, and some Charlieplexing later, he had a nice looking clock that his kids were sure to enjoy.

If you’re interested in seeing more about how constructed, be sure to check out his YouTube channel and Instructable, where he happily provides all of the build details.

Making Sure A Baby Is Still Breathing With Lasers And A Wiimote

August 21, 2012 by 66 Comments

[Gjoci] just became a father, and to make up for not having to carry a baby to term he decided to make himself useful in another way. He developed a sensor to detect a baby’s breathing, allaying the fears of nervous parents who are wondering why their child is so quiet.

Unlike similar builds and products that rely on microphones or capacitive sensors, [Gjoci]’s build uses the camera from a wiimote to triangulate points of light and detect motion.

The build started off with infrared LEDs, but the batteries were big and there is always the possibility of the baby swallowing electrical components. [Gjoci] finally hit upon the idea of using small 1mW laser diodes to project points of light. This worked beautifully, and since newborns don’t move much there’s no danger of shining a laser into a baby’s eye.

The rest of the build is just querying the camera every few milliseconds and seeing if the position of the reflections captured by the wiimote camera have changed. In two weeks of operation, [Gjoci] only had to respond to a few false alarms, and the hardware hasn’t crashed at all.

After the break are three videos [Gjoci] put up for us that show a test of the breathing detection system, a demo of the alarm, and an example of the build in full operation. A very awesome build, and we look forward to this post being used as evidence of prior art in a patent dispute a few years down the line.

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