Make Your Own Flexible Panel Lights

August 3, 2019 by 7 Comments

In this day and age, production values are everything. Even bottom-rung content creators are packing 4K smartphones and DSLRs these days, so if you want to compete, you’re gonna need the hardware. Lighting is the key to creating good video, so you might find a set of flexible panel lights handy. Thankfully, [DIY Perks] is here to show you how to build your own. (Video embedded below.)

The key to building a good video light rig is getting the right CRI, or Color Rendering Index. With low CRI lights, colors will come out looking unnatural or with odd casts in your videos. [DIY Perks] has gone to the effort of hunting down a supplier of high-quality LED strips in a range of different color temperatures that have a high CRI value, making them great for serious video work.

To build the flexible panel, the LED strips are glued onto a fake leather backing pad, which is then given a steel wire skeleton to enable it to be bent into various shapes. Leather loops are built into each corner of the panel as well, allowing the light to be fitted to a stand using a flexible aluminium bracket. The LEDs are slightly under-volted to help them last longer and enable them to run from a laptop power supply.

The build is one that focuses on light quality and usability, rather than just throwing a bunch of bright LEDs at the problem and calling it good. The results are great, with the panel showing a significant improvement on [DIY Perks]’s earlier builds.
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Maybe The Oldest Computer, Probably The Oddest

August 3, 2019 by 39 Comments

[Tadao Hamada] works for Fujitsu Tokki, a subsidiary of the more famous Fujitsu. In 1956, Fujitsu decided to compete with IBM and built a relay-based computer, the FACOM128. The computer takes up 70 square meters and weighs about 3 tons. By 1959, they’d learned enough to make a FACOM128B model that was improved. [Hamada’s] job is to keep one of these beasts operational at Fujitsu’s Numazu plant. According to the Japanese Computer Museum, it may be the oldest working computer.

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An All-Iron Battery Isn’t Light, But It’s Cheap

August 3, 2019 by 44 Comments

Rechargeable batteries are a technology that has been with us for well over a century, and which is undergoing a huge quantity of research into improved energy density for both mobile and alternative energy projects. But the commonly used chemistries all come with their own hazards, be they chemical contamination, fire risk, or even cost due to finite resources. A HardwareX paper from a team at the University of Idaho attempts to address some of those concerns, with an open-source rechargeable battery featuring electrode chemistry involving iron on both of its sides. This has the promise of a much cheaper construction without the poisonous heavy metal of a lead-acid cell or the expense and fire hazard of a lithium one.

A diagram of the all-iron cell.
A diagram of the all-iron cell.

The chemistry of this cell is split into two by an ion-exchange membrane, iron (II) chloride is the electrolyte on the anode side where iron is oxidised to iron 2+ ions, and Iron (III) chloride on the cathode where iron is reduced to iron hydroxide. The result is a cell with a low potential of only abut 0.6V, but at a claimed material cost of only $0.10 per kWh Wh of stored energy. The cells will never compete on storage capacity or weight, but this cost makes them attractive for fixed installations.

It’s encouraging to see open-source projects coming through from HardwareX, we noted its launch back in 2016.

Thanks [Julien] for the tip.

Antenna Tuning For GHz Frequencies

August 3, 2019 by 9 Comments

Antenna tuning at HF frequencies is something that radio amateurs learn as part of their licence exam, and then hone over their time operating. A few basic instruments and an LC network antenna tuner in a box are all that is required, and everything from a bit of wet string to ten thousand dollars worth of commercial antenna can be loaded up and used to work the world. When a move is made into the gigahertz range though it becomes a little more difficult. The same principles apply, but the variables of antenna design are much harder to get right and a par of wire snippers and an antenna tuner is no longer enough. With a plethora of GHz-range electronic devices surrounding us there has been more than one engineer sucked into a well of doom by imagining that their antenna design would be an easy task.

An article from Baseapp then makes for very interesting reading. Titled “Antenna tuning for beginners“, it approaches the subject from the perspective of miniature GHz antennas for IoT devices and the like. We’re taken through the basics and have a look at different types of antennas and connectors, before being introduced to a Vector Network Analyser, or VNA. Here is where some of the Black Art of high frequency RF design is laid bare, with everything explained through a series of use cases.

Though many of you will at some time or other work with these frequencies it’s very likely that few of you will do this kind of design exercise. It’s hard work, and there are so many ready-made RF modules upon which an engineer has already done the difficult part for you. But it does no harm to know something about it, so it’s very much worth taking a look at this piece.

It’s an area we’ve ventured into before, at a Superconference a few years ago [Michael Ossmann] gave us a fundamental introduction to RF design.

Simulate Climate With An Arduino

August 2, 2019 by 16 Comments

Greenhouses create an artificial climate specifically suited to the plants you want to grow. It’s done by monitoring conditions like temperature and humidity, and making changes using things like vents, fans, irrigation, and lighting fixtures to boost temperature. But how do you know when it’s time to up the humidity, or vent some of the heat building up inside? The easy way is to use the Arduino-powered Norman climate simulator from [934Virginia] which leverages data from different locations or times of year based on NOAA weather data to mimic a particular growing environment.

Norman relies on a simple input of data about the target location, working from coordinates and specified date ranges to return minimum/maximum values for temperature and humidity weather conditions. It makes extensive use of the Dusk2Dawn library, and models other atmospheric conditions using mathematical modeling methods in order to make relatively accurate estimates of the target climate. There are some simulations on the project’s Plotly page which show what this data looks like.

This data is used by [934Virginia’s] Arduino library to compare the difference between your target climate and actual sensor readings in your greenhouse. From there you can make manual changes to the environment, or if you’re luck and already have an Arduino-based greenhouse automation system the climate adjustments can be done automatically. The project is named after Norman Borlaug, a famous soil scientist and someone worth reading about.

Editor’s Note: This article has been rewritten from the original to correct factual errors. The original article incorrectly focused on replicating a climate without the use of sensors. This project does require sensors to compare actual greenhouse conditions to historic climate conditions calculated by the library. We apologize to [934Virginia] for this and thank them for writing in to point out the errors.

Images courtesy of Wikimedia Commons.

Memristor Computing On A Chip

August 2, 2019 by 8 Comments

Memristors have been — so far — mostly a solution looking for a problem. However, researchers at the University of Michigan are claiming the first memristor-based programmable computer that has the potential to make AI applications more efficient and faster.

Because memristors have a memory, they can accumulate data in a way that is common for — among other things — neural networks. The chip has both an array of nearly 6,000 memristors, a crossbar array, along with analog to digital and digital to analog converters. In fact, there are 486 DACs and 162 ADCs along with an OpenRISC processor.

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How To Build A CubeSat

August 2, 2019 by 3 Comments

There was a time when building your own satellite and having it placed into orbit would have been a wild dream. Now it is extremely possible, but still not trivial. A CubeSat is a very small satellite that can hitch a ride with a bigger satellite or get tossed out of a friendly space station. This week’s issue of The Orbital Index has a very good overview of what all is required. It also contains a great selection of links to get more information.

At first glance, it seems like it would be pretty simple. A computer, a battery, and some solar cells. Well, you probably want to hear back from it, so then you need a radio. Oh, and an antenna. But the antenna can’t stick out during launch so you need a way to deploy it. If you want the satellite to point somewhere, you’ll need things for that, too. Some CubeSats even have tiny thrusters to affect their orbit.

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