Bright White Night Light Fights E-Waste

August 31, 2020 by Kristina Panos 4 Comments

E-waste is a gigantic problem, and it can seem impossible as a lone individual to make any kind of dent in it. But [akshar1101] is trying to do their part by looking past the defective aspects of broken, discarded electronics to draw out the possibilities of what’s left.

This friendly night light is made from the PCBs of four broken Nokia 5110 LCD modules. The screens were all toast, but the nice white LEDs that used to light them from the sides work just fine. [akshar1101] cleverly tied all the LED and GND lines together with single right-angle header pins. To power the LEDs, they wired up a JST receptacle to one of the PCBs and connected a 3.7 V lithium battery pack that sits underneath. [akshar1101] diffused the piercing white lights into a soft glow with two pieces of acrylic.

We love to see electronic components get saved from landfills, especially when they can be turned into something useful and beautiful. Something about the traces on these boards makes them visually interesting to us — it’s that little hiccup that interrupts otherwise parallel lines.

If all of your 5110 LCDs are in working order, you could spice one of them up with an RGB backlight.

Free Refrigeration In Hot Climates

August 21, 2020 by Bryan Cockfield 34 Comments

Passive homes are a fairly recent trend in home building, but promise a future with minimal energy inputs in our day-to-day. One of the challenges in this year’s Hackaday Prize is to envision ways to add utility to earthen homes often used in refugee camps where there is a housing crisis. Adding passive utilities to these adobe buildings would be a fantastic upgrade, so [Cat] decided to tackle the challenge by creating a refrigerator that needs no electricity.

The the plan for the device works by using evaporative cooling to reduce the temperature in a small box which can be used for food storage. Of course, using evaporative cooling means that you need ready access to water and it likely won’t work in a humid or cool environment, but systems like these have been in use for centuries in plenty of places around the world. [Cat]’s plan is a little more involved than traditional methods of evaporative cooling though, and makes use of a specially painted chimney which provides the airflow when heated by sunlight.

The project is still in its infancy but it would be interesting to see a proof-of-concept built in a real-life passive house in an arid environment. Unfortunately, those of us in humid (or tropical) environments will have to look elsewhere for energy-efficient cooling solutions.

Building The Ultimate Raspberry Pi Automation Controller

August 19, 2020 by Tom Nardi 34 Comments

At this point, we’ve lost count of how many automation projects we’ve seen with some variant of a Raspberry Pi at the helm. Which is hardly surprising, as the boards are cheap, powerful, and well documented. The list of reasons not to use one has never been very long, but with the PiCon One that [Frank] has been working on, it’s about to get even shorter.

The project takes the form of an IP65 industrial enclosure and support electronics that the Raspberry Pi Zero W plugs into. While expandable in nature, [Frank] has a core set of features he’s aiming for as a baseline such as additional serial ports, integrated uninterruptible power supply, a battery-backed Real Time Clock (RTC), an array of programmable status LEDs, and support for XBee and GPS plug-in modules. Feedback is provided through a pair of four digit seven-segment displays and a color 320×480 TFT screen running a custom user interface.

[Frank] envisions the PiCon One for use as a rugged solar power controller, eventually able to measure array output, energy consumption, and even operate motorized mounts to keep the panels pointed at the sun. To that end, he’s recently been experimenting with running JPL’s Horizon software on the Pi to determine the sun’s position in real-time. But the device is capable of so much more, and would make an ideal controller for many home and potentially even industrial applications.

Continue reading “Building The Ultimate Raspberry Pi Automation Controller” →

Draw On Your Lawn With This Autonomous Mower And RTK-GPS

August 16, 2020 by Adil Malik 9 Comments

The rise of open source hardware has seen a wide variety of laborious tasks become successfully automated, saving us humans a great deal of hassle. Suffice to say, some chores are easier to automate than others. Take the classic case of a harmless autonomous vacuum cleaner that can be pretty dumb, bumping around the place to detect the perimeter as it traverses the room blindly with a pre-programmed sweeping pattern.

Now in principle, this idea could be extended to mowing your lawn. But would you really want a high speed rotating blade running rampant as it aimlessly ventures outside the perimeter of your lawn? The Sunray update to the Ardumower autonomous lawn mower project has solved this problem without invoking the need to lay down an actual perimeter wire. As standard consumer grade GPS is simply not accurate enough, so the solution involves implementing your very own RTK-GPS hardware and an accompanying base station, introducing centimeter-level accuracy to your mowing jobs.

RTK-GPS, also known as Carrier Phase Enhanced GPS, improves the accuracy of standard GPS by measuring the error in the signal using a reference receiver whose position is known accurately. This information is then relayed to the Ardumower board over a radio link, so that it could tweak its position accordingly. Do you need the ability to carve emojis into your lawn? No. But you could have it anyway. If that’s not enough to kick off the autonomous lawnmower revolution, we don’t know what is.

Continue reading “Draw On Your Lawn With This Autonomous Mower And RTK-GPS” →

Vintage Ammeter Becomes Plant Moisture Gauge

August 15, 2020 by Lewin Day 15 Comments

It’s not uncommon to happen across vintage measurement equipment at the local flea market or garage sale. Often with an irresistible aesthetic, and built to last decades, these tools nonetheless tend to be sidelined when modern multimeters are available. [Build Comics] had just such a piece on hand, and decided to repurpose it with some modern hardware instead.

The build begins with a Hartmann & Braun 60 amp ammeter. Replete in a nice wooden box, it’s the perfect candidate for a modern refit. The device uses an indicator of the moving iron type. Intending to turn the device into a soil moisture monitor, [Build Comics] began by removing the original heavy-wound coil. In its place, a custom coil was installed instead, wound on a 3D printed bobbin using a modified sewing machine. This allows the meter to be easily driven by an Arduino with little more than a transistor on a GPIO pin. To detect moisture, a Iduino ME110 moisture probe was used. Complete with cloth-covered wire to maintain the vintage look. The original meter plate was also photographed, modified, and reprinted, to read moisture levels instead of current.

If you’re interested in these gauge restoration techniques but don’t have a green thumb, no worries. [Build Comics] used similar tricks to put together a gorgeous weather station that would look great on your desk.

Continue reading “Vintage Ammeter Becomes Plant Moisture Gauge” →

Our Trucks Won’t Need No Batteries! Electric Trucks Look To Overhead Wires For Power

August 11, 2020 by Jenny List 212 Comments

As the world grapples with the spectre of the so-called “hockey stick” graph of climate change, there have been a variety of solutions proposed to the problem of carbon emissions from sectors such as transport which have become inseparable from the maintenance of 21st century life. Sometimes these are blue-sky ideas that may just be a little bit barmy, while other times they make you stop and think: “That could just work!”.

Such an idea is that of replacing the diesel engines in trucks with electric motors powered not by batteries but from overhead cables. An electric tractor unit would carry a relatively small battery for last-mile transit, but derive its highway power by extending a pantograph from its roof to a high-voltage cable above the road. It’s extremely seductive to the extent that there have even been trials of the system in more than one country, but does it stack up to a bit of analysis?

Time’s Up For Those Big Rigs

Siemens and Scania are justifiably proud of their electrified stretch of autobahn and electric trucks in Germany.

One thing that should be obvious to all is that moving our long-distance freight around by means of an individual fossil-fuel-powered diesel engine for every 38 tonne or so freight container may be convenient, but it is hardly either fuel-efficient or environmentally friendly The most efficient diesel engines on the road are said to have a 43% efficiency, and when hauling an single load they take none of the economies of scale afforded to the diesel engines that haul for example a freight train. Similarly they spread any pollution they emit across the entirety of their route, and yet again fail to benefit from the economies of scale present in for example a power station exhaust scrubber. However much I have a weakness for the sight of a big rig at full stretch, even I have to admit that its day has passed.

The battery technology being pursued for passenger cars is a tempting alternative, as we’ve seen with Tesla Semi. But for all its technology that vehicle still walks the knife-edge between the gain in cost-effectiveness versus the cost of hauling around enough batteries to transport that quantity of freight. Against that the overhead wire truck seems to offer the best of both worlds, the lightness and easy refueling of a diesel versus the lack of emissions from an electric. In the idealised world of a brochure it runs on renewable wind, sun, and water power, so all our problems are solved, right? But does it really stack up?

Continue reading “Our Trucks Won’t Need No Batteries! Electric Trucks Look To Overhead Wires For Power” →

Liquid Air Energy Storage: A Power Grid Battery Using Regular Old Ambient Air

July 24, 2020 by Kristina Panos 83 Comments

When you think of renewable energy, what comes to mind? We’d venture to guess that wind and solar are probably near the top of the list. And yes, wind and solar are great as long as the winds are favorable and the sun is shining. But what about all those short and bleak winter days? Rainy days? Night time?

Render of a Highview LAES plant. The air is cleaned, liquefied in the tower, and stored in the white tanks. The blue tanks hold waste cold which is reused in the liquefaction process. Image via Highview Power

Unfavorable conditions mean that storage is an important part of any viable solution that uses renewable energy. Either the energy itself has to be stored, or else the means to produce the energy on demand must be stored.

One possible answer has been right under our noses all along — air. Regular old ambient air can be cooled and compressed into a liquid, stored in tanks, and then reheated to its gaseous state to do work.

This technology is called Cryogenic Energy Storage (CES) or Liquid Air Energy storage (LAES). It’s a fairly new energy scheme that was first developed a decade ago by UK inventor Peter Dearman as a car engine. More recently, the technology has been re-imagined as power grid storage.

UK utility Highview Power have adopted the technology and are putting it to the test all over the world. They have just begun construction on the world’s largest liquid air battery plant, which will use off-peak energy to charge an ambient air liquifier, and then store the liquid air, re-gasifying it as needed to generate power via a turbine. The turbine will only be used to generate electricity during peak usage. By itself, the LAES process is not terribly efficient, but the system offsets this by capturing waste heat and cold from the process and reusing it. The biggest upside is that the only exhaust is plain, breathable air.

Continue reading “Liquid Air Energy Storage: A Power Grid Battery Using Regular Old Ambient Air” →