Energy efficient fridge hack

Green_Freezer

We’ve already covered a pipe bomb mini-fridge this week, but inventor [Tom Chalko] provides us with today’s fridge hack. He noticed that chest-style (laying down, see above) freezers were more energy efficient when compared to normal stand up refrigerators at the same size, despite the colder temperatures involved. This is largely due to the fact that these chest-style freezers keep cold air in like water in a bowl, even if the lid is open. He has written a very thorough report on his findings (pdf), as well as a detailed walk through of the manageable task of converting a chest-style freezer into a chest-style fridge. In the end, his fridge only used 103 Wh of electricity on the first day to reach and maintain between 4° and 7° C (39° to 45° F), and he noted that 30% of that was just getting it up to temperature. After that, the fridge only turned on for roughly 90 seconds an hour, making it a very quiet fridge as well.

Vonage on iPhone

vPhone2

Vonage has promised to release an official iPhone app to compete with other providers such as Skype, and it is currently working its way through Apple’s well documented approval process. Unfortunately, this app would most likely come with an initial cost and/or subscription fee, though a way has been figured out to retrieve Vonage’s SIP authentication information, which would allow use of the Vonage network over other iPhone SIP Clients such as Fring. This solution does still contain the Wi-Fi only clause, but we have ways of making you talk, iPhone. This could also possibly be used on other platforms with SIP clients such as Android or WinMo.

Simple, low-tech attack on Credit Unions

credit

The National Credit Union Administration is warning all Credit Unions about malicious hackers and a low tech attack by mailing branches CDs with malware on them.

Using a somewhat dated but still effective Social Engineering attack, a package designed to look as though it was mailed by the NCUA is sent to the branch. The package contains CDs with the attacker’s malware on it, and an accompanying letter (PDF) which informs the branches, ironically, about phishing scams. The letter directs the personnel to review the “training material” on the enclosed CD. Once branch employees proceed as directed, the malware is executed and gives the attackers access to the branch computer systems. Credit Unions seem to be targeted because they tend to be smaller local associations rather then larger banks with higher budgets for computer security.

When people think computer security, they usually envision high tech systems comprising of long passwords, expensive hardware, and updating software with the latest security patches. However, as famed social engineer and hacker Kevin Mitnick once said, “There is no patch for stupidity”.

[via threat post]

Phasma insectoid

When we saw the video of the Phasma insectoid robot above, we immediately thought of the iSprawl. After checking out their site, it turns out that the two are connected in some way, we’re not sure how, maybe just inspiration. The Phasma gives us a little more insight into the construction of the bot. The photos are highly detailed so you can see how the drive works, using the sliding cables to extend the “feet”. It seems quite agile in the video. The drive system, working off of a single cam seems like it would be easy to convert to steam. We would love to see that.

[via the pink tentacle]

DIY 3D gets a nod at SIGGRAPH

3dscan

Among the courses at this year’s SIGGRAPH (an annual technical conference and showcase of the latest in computer graphics research) was an introduction to 3D scanning that covers all the bases: mathematical foundations, two different build-your-own hardware approaches, and how to process and render the resulting datasets. The presenters have assembled all the course materials on a top-notch web site featuring slide shows, complete source code, and an extensive round-up with links to both commercial and homebrew 3D scanning gear. The simplest of these methods requires nothing more than a webcam, halogen light source, and a stick!

SIGGRAPH and 3D scanning have been highlighted many times on Hack a Day, but we’re swelling with pride now seeing an academic venue give a favorable nod to the DIY hacking community (on their links page). Okay, so Hack a Day isn’t called out by name, but just wait’ll next year!

[Thanks Fahrzin]

Interfacing a digital rotary switch

digital_rotary_switch

[hw640] has put together a well written and detail packed explanation of how to interface with a digital rotary switch. These digital opto encoders have just two outputs with four possible logic levels (00, 10, 11, 01). The relative position of the switch is insignificant but the direction of rotation is what matters.

The short and dirty: Each of the switch’s 2 output pins is attached to a pin change interrupt on the microcontroller. Every time the switch moves it generates either a rising edge or a falling edge on one of the two pins; both edges cause an interrupt. By checking which pin caused the interrupt, then comparing the logic levels of the two pins after that interrupt, we can determine the direction the switch was rotated.

Although this explanation uses a PIC and code written in PicBasic Pro the concepts are discussed in the abstract and would easily be adapted to an AVR or another microcontroller of your choice.

Ubuntu repository crash-course

[Alan] has just posted an Ubuntu screencast that will take you through a crash course in the Ubuntu repositories. If you are new to Ubuntu this will give you a much better grasp on how software repositories are handled.

The different types of updates are discussed: Security updates fix bugs that cause a system vulnerability. Updates (generic) are for bug fixes that aren’t a security threat. Proposed updates are for testing before an update hits the ‘updates’ section. Finally, backports are updates from a newer version that have been ‘backported‘ so systems running older versions of Ubuntu can have the benefit of newer features and fixed bugs.

He also provides some tips on selecting package sources (main, universe, restricted, and multiverse), and choosing the fastest mirror to reduce download times. This screencast is just part one and we hope to see 3rd party repositories, personal package archives, and repository caching covered in future installments.

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