Moldy Rechargeable Batteries

March 24, 2016 by 24 Comments

What’s worse than coming in from the workbench for a sandwich only to discover that the bread has molded? That red bread mold–Neurospora crassa–can transform manganese into a mineral composite that may improve rechargeable batteries, according to a recent paper in Current Biology.

Researchers used the carbonized fungal biomass-mineral composite in both lithium ion cells and supercapacitors. The same team earlier showed how fungi could stabilize toxic lead and uranium. Mold, of course, is a type of fungus that grows in multi-cellular filaments. Apparently, the fungal filaments that form are ideal for electrochemical use of manganese oxide. Early tests showed batteries using the new material had excellent stability and exceeded 90% capacity after 200 discharge cycles.

The team plans to continue the use of fungus in various metallurgical contexts, including recovering scarce metal elements. This is probably good news for [Kyle]. This is quite an organic contrast to the usual news about graphene batteries.

Image: Qianwei Li and Geoffrey Michael Gadd

Flying Close To The Flame: Designing Past Specified Limits

March 24, 2016 by 23 Comments

A very good question came up on The EEVBlog forum that I thought deserved an in depth answer. The poster asked why would amplifier companies in the heyday of tube technology operate tubes in mass produced circuits well in excess of their published manufacturers recommended limits. The simple answer is: because the could get away with it. So the real question worth exploring is how did they get away with operating outside of their own published limitations? Let’s jump in and take a look at the collection of reasons.

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An Affordable Panasonic Grid-EYE Thermal Imaging Camera

March 24, 2016 by 20 Comments

Thermal imaging cameras are objects of desire for hackers and makers everywhere, but sadly for us they can be rather expensive. When your sensor costs more than a laptop it puts a brake on hacking.

Thankfully help is at hand, in the form of an affordable evaluation board for the Panasonic Grid-EYE thermal imaging camera sensor. This sensor has sparked the interest of the Hackaday community before, featuring in a project that made the 2014 Hackaday Prize semifinals, but has proved extremely difficult to obtain.

All that has now changed though with this board. It features the Grid-EYE sensor itself, an Atmel ATSAM-D21G18A microcontroller, and onboard Bluetooth, but has an interesting feature that, as well as being a standalone device, can be used as an Arduino shield. A full range of APIs are provided, and the code is BSD licensed.

This module is not the highest-spec thermal imaging camera on the market by any means, after all it has a resolution of only 64 pixels in an 8×8 grid. But its affordability and easy availability should trigger a fresh crop of thermal camera projects in our community, and we applaud that.

Thermal camera projects have featured quite a few times here on Hackaday. Some have been based on the FLIR Lepton module, like this one that combines its image with a 640×480 visible camera and another that claims to be one of the smallest thermal cameras, while others have harnessed raw ingenuity to create a thermal camera without a sensor array. This pan-and tilt design for example, or this ingenious use of light painting. Please, keep them coming!

[via oomlout]

Mirror Monitor Responds To Your Gestures

March 24, 2016 by 20 Comments

[DerVonDenBergen] and his friend are working on a pretty slick mirror LCD with motion control called Reflecty — it looks like something straight out of the Iron Man movies or the Minority Report.

Like most mirror monitors they started with a two way mirror and a de-bezelled LCD — but then they added what looks like an art gallery light off the top — but instead of a light bulb, the arm holds a Leap Motion controller, allowing gesture commands to be given to the computer.

The effective range of the Leap Motion controller is about 8-10″ in front of the display allowing you to reach out and point at exactly what you want — and then squeeze your fist to click. A complete gallery of images is available over on Imgur, but stick around after the break to see a video of the display in action — we kind of want one.

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Growing Algae For Fun And Profit

March 23, 2016 by 53 Comments

Supposedly, writes [Severin], algae is a super food, can be used as biofuel, and even be made into yoga mats. So he’s built an algal reactor at Munich Maker Lab, to try to achieve a decent algal yield.

You might expect that  sourcing live algae would be as simple as scraping up a bit of green slime from a nearby pond, but that yields an uncertain mix of species. [Severin] wanted Chlorella algae for his experiment because its high fat content makes it suitable for biodiesel experiments, so had to source his culture from an aquatic shop.

The reactor takes the form of a spiral of transparent plastic tube surrounding a CFL lamp as a light source, all mounted on a lasercut wooden enclosure housing a pump. A separate glass jar forms a reservoir for the algal-rich water. He does not mention whether or not he adds any nutrient to the mix.

Left to its own devices the machine seems to work rather well, a 48 hour session yielding an impressively green algal soup. Sustained running does cause a problem though, the pipes block up with accumulated algae and the machine needs cleaning by blasting it with high pressure water and a healthy dose of nuts and bolts.

This isn’t the first algal reactor we’ve featured here on Hackaday, we had this Arduino-powered one back in 2009. But mostly the algae that have appeared here have been of the bioluminescent variety, as with this teaching project, or this night light.

BlinkenBone Meets The PiDP8

March 23, 2016 by 10 Comments

Years ago when the old mainframes made their way out of labs and into the waiting arms of storage closets and surplus stores, a lot got lost. The interesting bits – core memory boards and the like – were cool enough to be saved. Some iconic parts – blinkenlight panels – were stashed away by techs with a respect for our computing history.

For the last few years, [Jörg] has been making these blinkenlight panels work again with his BlinkenBone project. His work turns a BeagleBone into a control box for old console computers, simulating the old CPUs and circuits, allowing them to work like they did thirty years ago, just without the hundreds of pounds of steel and kilowatts of power. Now, [Jörg] has turned to a much smaller and newer blinkenlight panel, the PiDP-8.

The PiDP-8 is a modern, miniaturized reproduction of the classic PDP 8/I, crafted by [Oscar Vermeulen]. We’ve seen [Oscar]’s PiDP a few times over the last year, including a talk [Oscar] gave at last year’s Hackaday Supercon. Having a simulated interface to a replica computer may seem ridiculous, but it’s a great test case for the interface should any older and rarer blnkenlight panels come out of the woodwork.

Homebrew Multimode Digital Voice Modem

March 23, 2016 by 20 Comments

There’s an old saying that the nice thing about standards is there are so many of them. For digital voice modes, hams have choices of D-Star, DMR, System Fusion, and others. An open source project, the Multimode Digital Voice Modem (MMDVM), allows you to use multiple modes with one set of hardware.

There are some kits available, but [flo_0_] couldn’t wait for his order to arrive. So he built his own version without using a PCB. Since it is a relatively complex circuit for perf board, [flo_0_] used Blackboard to plan the build before heating up a soldering iron. You can see the MMDVM in action below.

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