The Surface Area To Volume Ratio Or Why Elephants Have Big Ears

April 18, 2017 by Manuel Rodriguez-Achach 48 Comments

There are very few things that are so far reaching across many different disciplines, ranging from biology to engineering, as is the relation of the surface area to the volume of a body. This is not a law, as Newton’s second one, or a theory as Darwin’s evolution theory. But it has consequences in a diverse set of situations. It explains why cells are the size they are, why some animals have a strange morphology, why flour explodes while wheat grains don’t and many other phenomena that we will explore in this article.

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Making Tension Based Furniture

April 18, 2017 by Michael Uttmark 21 Comments

[Robby Cuthbert,] an artist and designer based out of Fort Collins, Colorado is creating stable cable tables that are simultaneously a feat of engineering and a work of art.

[Cuthbert’s] tables are held together by 1/16″ stainless steel cables that exert oppositional tensions that result in a structurally stable and visually appealing coffee table. In his video, [Cuthbert] leads us through his process for creating his tables, step by step. [Cuthbert] starts by cutting out bamboo legs on his CNC mill. He then drills holes in each leg for cables and mounts each leg on his custom table jig. Then, he attaches the stainless steel cabling taking care to alternate tension direction. The cables are threaded through holes in the legs and affixed with copper crimps. After many cables, he has a mechanical structure that can support his weight that also looks fantastic. All in all, [Cuthbert’s] art is a wonderful example of the intersection of art and engineering.

If we’ve whet your appetite, fear not, we have featured many tension based art/engineering hacks before. You might be interested in these computer-designed portraits or, if the thought of knitting by hand gives you the heebie-jeebies, the Autograph, a string art printer might be more your style.

Video after the break.

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Brazil Wins The Raspberry Pi Overclocking Olympics

April 18, 2017 by Adil Malik 20 Comments

[Alex Rissato] proudly reports that he now holds the record for highest benchmark score on HWBOT (machine translation); something he sees not only as a personal achievement but admirably, of national pride. Overclocking a Raspberry Pi is not as simple as achieving the highest operational clock rate. A record constitutes just the right combination of CPU clock, memory clock, GPU clock and finally the CPU core voltage. If you’ve managed to produce that special sauce, the combination must be satisfactorily cooled and most importantly be stable enough to pass an actual performance benchmark.

[Alex] realized that the main hurdle to achieving the desired CPU clock was the internally generated and hence restricted, CPU core voltage; This is externally LC filtered and routed back to the CPU on a stock Pi. [Alex] de-soldered the filter on the PCB and provided the CPU with an externally generated core voltage.

Next, the cooling had to be tended to. Air cooling simply wouldn’t cut it, so a Peltier based heatsink interface had to be devised with the hot side immersed in a bucket of salt water. All of this translated to a comfy 16C at a clock speed of 1600 MHz.

Was all the effort justified? We certainly think it was! Despite falling short of the Pi zero CPU clock rate record, currently set at 1620MHz, [Alex] earned the top spot in the HWBOT Prime overclocking benchmark. Brazil can now certainly add this to its trophy cabinet, arguably overshadowing the 129 Olympic medals.

A Real Hacker’s IDE

April 17, 2017 by Elliot Williams 40 Comments

We don’t use a GUI IDE, but if we did, it would most certainly be something along the lines of [Martin]’s embedded-IDE project. We’ve always felt that most IDEs are just fancy wrappers around all the tools that we use anyway: Makefiles, diff, git, ctags, and an editor. [Martin]’s project makes them less fancy, more transparent, and more customizable, while retaining the functionality. That’s the hacker’s way — putting together proven standard tools that already work.

The code editor he uses is QScintilla, which uses clang for code completion. The “template” system for new projects? He uses diff and patch to import and export project templates. Because it uses standard tools all along the way, you can install the entire toolchain with sudo apt-get install clang diffutils patch ctags make on an Ubuntu-like system. Whatever compiler you want to use is supported, naturally.

We can’t see a debugger interface, so maybe that’s something for the future? Anyway, if you want a minimalistic IDE, or one that exposes the inner workings of what it’s doing rather than hiding them, then give [Martin]’s IDE a try. If you want more bells and whistles that you’re not going to use anyway, and don’t mind a little bloat and obscuration, many of our writers swear by Eclipse, both for Arduino and for ARM platforms. We’ll stick to our butterflies.

A Smart Switch Board For The ESP8266

April 17, 2017 by Jenny List 20 Comments

With a plethora of IoT projects and inexpensive commercial smart light fittings and mains switches appearing, you might be forgiven for thinking that another offering in this crowded marketplace would be superfluous. But there is always room for improvement in any field, and in this particular one [Xose Pérez] has done just that with his Espurna board.

This board is a very well executed ESP8266 mains relay, with an on-board mains power supply and power monitoring. It was designed with his Espurna (“Spark” in Catalan) custom firmware in mind, which offers support for Alexa, Domoticz, Home Assistant and anything that supports MQTT or HTTP REST APIs.

Best of all, it’s a piece of open source hardware, so you can download everything you need from his GitHub repository to create your own. For the ultimate in convenience you can even order the PCB ready-made from OSH Park.

As a demonstration of the Espurna board in a real application, he’s produced a smart socket project neatly enclosed in a wall-wart style box with an inbuilt Euro style plug and socket.

We’ve featured [Xose]’s work several times before here at Hackaday, he’s something of an IoT wizard. Most recently there was his work with Alexa and the ESP8266, but before that was his MQTT LED array for his laundry monitor.

This Binary Keyboard Is For ASCII Purists

April 17, 2017 by Jenny List 48 Comments

So, you’re a keyboard enthusiast. The ‘board that came from Dell, HP, or whoever made your computer is just not for you. You have an ancient IBM, a decal-free Das Keyboard, or another similarly esoteric text input device. Your typing can be heard three blocks away as the unmistakable clack of bent-spring switches reverberates around you, but you don’t care because you’re in the Zone.

No keyboard can be as high-end as the one you already have, your position in the hierarchy of text entry is assured. But then along comes [Chris Johnston] with his project, and suddenly your desktop looks very cluttered. It’s a binary keypad with only a 0 key, a 1 key, and an OLED display. All input is as a series of binary bytes, so as a hardcore binary typist you’ll need to know your ASCII.

Behind the keys is an Arduino Pro Micro acting in USB HID mode, and running the code you can download from the GitHub link above. It’s a gloriously pointless input device, but we’re sure you’ll agree it has something of the 00110001 00110011 00110011 00110111 about it.

If you think you may have seen this before on Hackaday then you’re not quite right. We have had a binary keypad in the past, but that one had a return key and thus had three keys. This one’s a 2-key ‘board for binary purists.

[via /r/mechanicalkeyboards/]

Prisoners Build DIY Computers And Hack Prison Network

April 17, 2017 by Jack Laidlaw 80 Comments

The Internet is everywhere. The latest anecdotal evidence of this is a story of prison inmates that build their own computer and connected it to the internet. Back in 2015, prisoners at the Marion Correctional Institution in Ohio built two computers from discarded parts which they transported 1,100 feet through prison grounds (even passing a security checkpoint) before hiding them in the ceiling of a training room. The information has just been made public after the release of the Inspector General’s report (PDF). This report is fascinating and worth your time to read.

This Ethernet router was located in a training room in the prison. Physical access is everything in computer security.

Prisoners managed to access the Ohio Department of Rehabilitation and Corrections network using login credentials of a retired prison employee who is currently working as a contract employee. The inmates plotted to steal the identity of another inmate and file tax returns under their name. They also gained access to internal records of other prisoners and checked out websites on how to manufacture drugs and DIY weapons, before prison officers were able to find the hidden computers. From the report:

The ODAS OIT analysis also revealed that malicious activity had been occurring within the ODRC inmate network. ODAS OIT reported, “…inmates appeared to have been conducting attacks against the ODRC network using proxy machines that were connected to the inmate and department networks.” Additionally, ODAS OIT reported, “It appears the Departmental Offender Tracking System (DOTS) portal was attacked and inmate passes were created. Findings of bitcoin wallets, stripe accounts, bank accounts, and credit card accounts point toward possible identity fraud, along with other possible cyber-crimes.”

The prisoners involved knew what they were doing. From the interview with the inmate it seems the computers were set up as a remote desktop bridge between internal computers they were allowed to use and the wider internet. They would use a computer on the inmate network and use a remote desktop to access the illicit computers. These were running Kali Linux and there’s a list of “malicious tools” found on the machines. It’s pretty much what you’d expect to find on a Kali install but the most amusing one listed in the report is “Hand-Crafted Software”.

This seems crazy, but prisoners have always been coming up with new ideas to get one over on the guards — like building DIY tattoo guns, When you have a lot of time on your hands and little responsibility, crazy ideas don’t seem so crazy after all.