An Improved Bubble Display With RGB LEDs

September 10, 2013 by Marsh 14 Comments

Making a bubble display is quite an undertaking, but [Jay] takes advantage of iterative design to construct this impressive (and at 60 tubes, massive) bubble display. The display functions by dispensing bubbles to serve as illuminated pixels in each tube as they rise through the fluid. His build log steps through the display’s construction with a keen attention to detail and above all, patience.

Rather than diving right in and slapping some tubes together, [Jay] took the time to research other bubble display projects, including one we featured a few years back that grew out of yet another HackaDay article. His prototypes started off small to test potential features: whether to use water or glycerin, timing for the air pumps and bubble size, and several others. [Jay] even filled the log with videos of every test, so you can watch the problems and solutions unfold at each step.

The finished display boasts sixty 30″ tall tubes, making it 64″ wide. [Jay] also installed RGB LEDs at every edge where the tubes meet to better distribute the light. You can watch one of the many videos of the display at work below.

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Graffiti Briefcase For Stealth Tagging

September 9, 2013 by Marsh 251 Comments

We’re floored by painter and engineer [Bob Partington’s] graffiti briefcase, which proves how well art and tech can complement one another. Fear not, Arduino haters, [Bob]’s case is an analog dream: no microcontrollers here.

The guts consist of 2 components: a linear drive system and a trigger assembly. The former takes advantage of a small RC motor with a chain drive which slides the can’s mounting unit along two stainless steel rods. The latter includes a custom wound solenoid plugged into a 24V cordless drill battery, which slams down 5 pounds of force onto the can’s nozzle to fire the paint.

This all fits into an otherwise inconspicuous looking briefcase to provide some urban camouflage. The final component is a stencil, which slides into a rectangular hole on the bottom of the case. The paint can sprays downward through the stencil and tags the ground at the touch of a brass button located near the handle. [Bob] has plenty of other cool inventions you should check out that are less illegal. Or, stick it to the man by automating your tagging with Time Writer.

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‘conus’ Mixes Media, Math And Mollusks

September 5, 2013 by Marsh 14 Comments

conusCA

We love art installations that use technology in ways probably never before considered, and Moscow media artist [Dimitry Morozov] has done just that with ‘conus’, which reads the surface of mollusk shells and translates the data into real-time audio and video. These shells are unique; their pigmentation generates natural cellular automata. (If you’ve never heard of cellular automata, Conway’s Game of Life is a good example, where a rule set determines whether a cell lives, dies, or regenerates.

[Dimitry’s] installation uses homemade digital microscopes to scan the naturally-created cellular automata of several shells, each rotating on its own disc. As the shell spins, the scans from the microscopes are fed into an algorithm which transforms the signals into data for multiple audio channels and three video monitors. You can watch the mathematical translation of the biologically-formed patterns in a video after the break.

Check out the MSP430 game of life shield for another example of cellular automata.

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Modifying The HC-05 Bluetooth Module Defaults Using AT Commands

September 4, 2013 by Mathieu Stephan 50 Comments

The HC-05, a Bluetooth to serial bridge, can be found for around $5 on the internet and therefore may be the cheapest way to add Bluetooth connectivity to your project.

However, its default settings may need to be changed depending on your application. [Hazim] explains a way to enter the HC-05 AT command mode to benefit from the rich set of features that the device can provide. The process is fairly simple as it only consists of maintaining the key pin of the HC-05 high while powering on. The device then boots in AT command mode with a default 38400bits/s speed and listens for all of the AT command set (PDF). As an example [Hazim] provides a sketch allowing you to write the AT commands directly in your favorite terminal.

With the basics out of your way you may want to further research the hardware, especially if you will be using modules from different sources. They don’t always come with the same firmware.

Laptop To All-in-one PC Conversion

September 4, 2013 by Marsh 10 Comments

laptop2allinone

You probably have an old laptop shoved into a far, dark corner of your closet, gathering dust as it sits there alone and unwanted. Show it some love like [Oakkar7] and hack it into a desktop all-in-one PC. He had his work cut out for him, though: dead motherboard, busted case, worthless battery. [Oakkar7] starts by taking the case apart and removing the LCD screen. He removes the motherboard to discover two toasted capacitors in need of replacement. A short solder job later and the computer springs to life.

[Oakkar7] needs the LCD to face outwards while sitting against the rest of the laptop. The connecting cable doesn’t reach, so he carefully removes it, and flips it around to get the extra length needed. The final step is to fashion some aluminum support bars that attach to the bottom of the case, which mount onto another aluminum stand holding everything upright. At this point [Oakkar7] has tossed the battery, the keyboard, both the CD and floppy drive (yes it’s that old), and moved the speakers into the battery’s former home. For the finishing touch, a USB hub provides connections for the new keyboard, mouse and a Wifi dongle.

[Oakkar7] shared his project with us after reading [Elad’s] ground control station laptop conversion. Maybe these two projects can convince you to save a neglected laptop.

A Weekend Trip To Verify General Relativity

September 3, 2013 by Mathieu Stephan 77 Comments

8 years ago, for the 100th anniversary of the theory of relativity [Tom] decided to test the general theory of relativity.

As he was going to Mt Rainier (5400ft high) with his children for the weekend, he brought in his van 3 cesium clocks while leaving other atomic clocks at his home for comparison. The theory behind the test is that if you’re are at higher altitudes, then your speed (in a galactic coordinate system) is higher than the one you’d have at sea level and therefore time would go “slower” than at lower altitudes.

[Tom] brought 400 pounds of batteries, 200 pounds of clocks and left his car turned on during his 2 days stay in the ‘Paradise Lodge’. He used 120V DC to AC converters and chose to bring 3 cesium clocks to have a triple redundant setup. When he came back home, he had the good surprise of finding a time difference of 23ns. This is a great application for those rubidium sources you’ve been scavenging.

[Thanks Indyaner via Reddit]

A Real Car Remote Controlled With An Arduino… What Could Go Wrong?

September 1, 2013 by Mathieu Stephan 39 Comments

[Gilad] tipped us about his latest project, where he adds plenty of pneumatics and electronics into his wife’s car to remote control it.

The brake/throttle pedals are actuated by pistons controlled by electronic valves, and a standard DC motor is in charge of turning the wheel. The Arduino code tells us that the valves will be opened as long as the remote up/down channel is above/under given values. The frame is based on Festo aluminium profiles and we’re not sure where the mains used for the DC/DC converters is coming from. As the valves use 24V and the motor 12V, standard N-Mosfets and power relays are used for voltage conversion. The remote controller [Gilard] used is actually 20 years old, so the output signal of the receiver isn’t actually really clean.

We do hope to never see this car on the road….