Computers May Someday Need A Drink

“We want to put water right into your processor.” If that statement makes you sweat, that is good. Sweating is what we’re talking about, but it’s more involved than adding some water like a potted plant. Sweating works naturally by allowing liquid to evaporate, and that phase change is endothermic which is why it feels cool. Evaporative coolers that work in this way, also known as swamp coolers, haven’t been put into computers before because they are full of sloshy water. Researchers in South Korea and the United States of America have been working on an evaporative cooling system mimicking the way some insects keep themselves cool by breathing through their exoskeletons while living in damp soil.

Springtails are little bugs that have to keep the water and air separate, so they don’t drown in the wet dirt where they live. Mother Nature’s solution was for them to evolve to do this with columns that have sharp edges at the exit. Imagine you slowly add water to a test tube, it won’t spill as soon as you reach the top, it will form a dome. This is the meniscus. At a large scale, say a river dam, as soon as you get over the dam you would expect spillage, but at the test tube level you can see a curve. At the scale of the springtail, exuded water will form a globe and resist water pressure. That resistance to water pressure allows this type of water cooling to self-regulate. Those globes provide a lot of surface area, and as they evaporate, they allow more water to replenish the globe. Of course, excessive pressure will turn them into the smallest squirt guns.

We have invented a lot by copying Mother Nature. Velcro was inspired by burrs, and some of our most clever robots copy insects. We can also be jerks about it.

3D Drone Video

If you enjoy flying quadcopters, it is a good bet that you’ll have a drone with a camera. It used to be enough to record a video for later viewing, but these days you really want to see a live stream. The really cool setups have goggles so you can feel like you are actually in the cockpit. [Andi2345] decided to go one step further and build a drone that streams 3D video. You can see a video of the system, below.

Outdoors, there’s probably not a lot of advantage to having a 3D view, but it ought to be great for a small indoor drone. The problem is, of course, a small drone doesn’t have a lot of capacity for two cameras. The final product uses two cameras kept in sync with a sync separator IC and a microcontroller, while an analog switch intersperses the frames.

On the viewing side, a USB frame grabber and a Raspberry Pi splits the images again. At first, the system used an LCD screen married with a Google Cardboard-style goggle, but eventually, this became a custom Android application.

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Got a Burning Idea For An EMF Camp Presentation? Now’s Your Chance!

Sometimes the world of tech conference presentations can seem impossibly opaque, a place in which there appears to be an untouchable upper echelon of the same speakers who pop up at conference after conference. Mere mortals can never aspire to join them and are destined to forever lurk in the shadows, their killer talk undelivered.

Thankfully, our community is not like that. There is a rich tradition of events having open calls for participation, and the latest we’d like to bring to your attention comes from the British EMF Camp, to be held at the end of August. EMF, (standing for ElectroMagnetic Field) is a 3-day festival that bills itself as “for those with an inquisitive mind or an interest in making things“. In their call for participation, they are seeking installations and performances as well as talks and workshops, and it’s worth saying given the very quick uptake of their early ticket sales, that a couple of tickets will be reserved for purchase by each person with proposals that are accepted.

EMF Camp like other hacker camps is an extraordinary coming together of people from all conceivable backgrounds and interest groups to share a field for three days. It doesn’t matter how experienced you are, what the subject is that you would like to present, or what installation or workshop you would like to bring, there will be a section of the EMF audience who would be very interested to see it. They list a few previous topics, from genetic modification to electronics, blacksmithing to high-energy physics, reverse engineering to lock picking, computer security to crocheting, and quadcopters to brewing. Assuming that certain submissions are accepted, you may also see a Hackaday scribe delivering a talk.

While you’re thinking of what to submit for 2018, whet your appetite with a look at the goings-on from EMF 2016.

Image: Nottingham Hackspace [CC BY-SA 2.0].

Roomba-Riding Beer Butlers Will Serve Us All

[Josh] isn’t one to refuse a challenge, especially when robots are involved. The latest dare from friends and family? Build a beer robot that can bring beverages at everyone’s beck and call.

The build consists of two main parts: the refrigerated cooler and the butler part, which comes courtesy of a Roomba Discovery from a fellow roboticist. [Josh] is basing the design on double-walled and insulated restaurant coolers. He built the refrigerated beverage hold from two stainless steel trash cans, sized an inch or so apart in diameter, and filled the gap with expanding foam insulation. He then cut away several inches from the bottom of the liner can to make room for the cooling unit, reinstalled the drip tray, and made a [airflow-allowing platform] by drilling a bunch of holes in an antimicrobial plastic cutting board.

At first, he tried a Peltier unit from an electric Igloo cooler, but that doesn’t work as well as [Josh] hoped, so he’s redesigning the can to use a mini fridge compressor. This meant making custom evaporator and condenser coils from copper tubing to match the compressor’s load spec. Go through [Josh]’s build logs over on IO and you’ll get a free mini-course on expanding foam and refrigeration.

[Josh] is currently working on some different butler modes for this robot. These run the gamut from simply sitting nearby with cold beverages and opening with the wave of a hand to doing voice-triggered beverage butler-ing at everyone’s beck and call. We applaud his efforts thus far and will be following this one with great thirst interest to see how he handles navigation and voice control.

Tracktorino Shields You From Poor Interfaces

On-screen controls in a digital audio workstation expand the power of a DJ or musician, but they are not intuitive for everyone. The tactility of buttons, knobs, sliders and real-world controls feels nothing like using a mouse, trackpad, or even a touchscreen. Unfortunately, devices meant to put control into a DJs hands can be unavailable due to location or cost. [Gustavo Silveira] took charge of the situation so he could help other DJs and musicians take control of their workstations with a customized MIDI interface for Traktor DJ software.

MIDI is a widely used serial protocol which has evolved from a DIN connector to USB, and now it is also wireless. This means that the Traktorino is not locked to Traktor despite the namesake. On the Hackaday.io page, there’s even a list of other workstations it will work with, but since many workstations, all the good ones anyway, accept MIDI hardware like this, the real list is a lot longer.

The custom circuit board is actually a shield. Using an Arduino UNO, the current poster child of the Arduino world, opens up the accessibility for many people who don’t know specialized software. A vector drawing for a lasercut enclosure is also included. This means that even the labeling on the buttons are not locked into English language.

Here’s another project which combined laser cutting and MIDI to make some very clever buttons or turn your DIN MIDI connector into USB.

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Building a POV Display On A PC Fan

We’ve covered plenty of persistence of vision (POV) displays before, but this one from [Vadim] is rather fun: it’s built on top of a PC fan. He’s participating in a robot building competition soon and wanted to have a POV display. So, why not kill two birds with one stone and build the display onto a fan that could also be used for ventilation?

The display is a stand-alone module that includes a battery, Neopixels, Arduino and an NRF240L01 radio that receives the images to be displayed. That might seem like overkill, but putting the whole thing on a platform that rotates does get around the common issue of powering and sending signals to a rotating display: there is no need for slip connections.

[Vadim] goes into a good level of detail on how he built the display, including the problems he had diagnosing a faulty LED chip, and why it is important to test at each stage as it is easier to debug when the display isn’t whizzing around at high speed.

It’s a bit of a rough build that uses more protoboard than might be necessary, but we’re keeping our fingers crossed that it doesn’t fly off during the competition.

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Nerf blaster goes next-level with propane power

There are no shortage of Nerf gun mods out there. From simply upgrading springs to removing air restrictors, the temptation of one-upping your opponents in a Nerf war speaks to many!

Not content with such lowly modifications [Peter Sripol] decided that his blaster needed to see some propane action.

[Peter] completely stripped out the existing firing mechanism before creating a new combustion chamber from some soldered copper pipe. He added a propane tank and valve on some 3D-printed mounts, and replaced the barrel to produce some intense firepower.

To ignite the fuel inside the combustion chamber, some taser circuitry creates the voltage needed to jump the spark gap inside whilst an added switch behind the trigger kicks off the whole process. After experimenting with different ignition methods, [Peter] eventually found that positioning the spark in the center of the chamber provided the best solution for efficient combustion and non-deafening volume.

Though highly dependant on the amount of gas in the chamber during combustion, the speed of the dart was able to reach a maximum of 220 fps – that’s a whopping 150mph!

Next follows the obligatory sequence for all souped-up Nerf guns:  slow motion annihilation of various food items and beverage containers. To obtain some extra punch, some custom Nerf darts were 3D-printed, including one with a fearsome nail spear-head.

We strongly advise against taking up [Peter] on any offer of Nerf based warfare, but you can check out his insane plane adventures or last winter’s air sled.

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