Is Your Movie Too Loud? Can’t Hear The Dialogue? This Circuit Can Help.

September 29, 2021 by Jim Heaney 67 Comments

Everyone loves watching movies, that is, so long as you can hear what the characters on screen are saying. [GreatScott] found this second part difficult while watching through BladeRunner 2049, so he designed an automatic volume adjuster to assist.

At a high level, the solution is fairly straightforward; when there is loud music playing in a movie, turn the volume down. The challenge is how to actually achieve that. The first step was controlling the volume. To avoid having to modify or damage his sound system, [GreatScott] opted instead to mimic the volume up and down signals of his remote over IR. Using the very handy IRremote library for Arduino and its built-in decoding functionality, he was able to identify and replicate the signals with his own IR LED.

The second step in this process was measuring the volume of the movie. [GreatScott] achieved this with a microphone and amplifier circuit, that was then piped into one of the analog pins of the Arduino Pro Micro at the heart of the build. Since the audio being sampled could have a frequency as high as 20 kHz, the ADC Prescaler had to be adjusted from its standard value, which would have only permitted measurements at less than 5 kHz.

The third step was writing the algorithm to detect loud music and adjust the volume accordingly. The Arduino will measure the audio until a sound greater than the dead band value, set with one of the two onboard potentiometers, is detected. This then triggers the Arduino to start a timer, to see how frequently the upper limit is being surpassed. If it is just one or two occasionally loud noises (like a scream, a clap, whistling, etc.) the Arduino will not take any action, but multiple loud noises in rapid succession will then trigger the volume down command over the IR LED. A second potentiometer allows for adjustment of this timer’s critical value, so that you can make the system respond faster or slower depending on the movie.

Once the sound has been detected to have dropped down below a critical vaue, the Arduino assumes that the movie is back to dialog and will increase the volume by the number of times it decreased it before, leaving you back at the perfect volume.

Maybe you’re the type that cares more for the visuals of a movie, rather than the audio. In that case, this e-paper movie display will be perfect for giving you time to appreciate every frame!

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A shirt with carbon nanotube threads stitched into a shirt monitor the wearer's heart rate.

Sew-able Carbon Nanotube Thread Could Spin A Lot Of Awesome

September 28, 2021 by Kristina Panos 18 Comments

Plenty of people just plain dislike wearing jewelry, even (or especially) smart watches. Nevertheless, they’d like to have biofeedback like everybody else. Well, we watch-less ones have something to look forward to, because a group of graduate students at Rice University have created extremely strong conductive thread woven from carbon nanotubes, which can be sewn into standard athletic clothing and used as electrodes, antennas, or simply as ballistic protection.

At 22 microns wide, the original carbon nanotubes were too skinny to use as thread. Instead, the team braided together three bundles of seven ‘tubes each using the type of machine that model boat builders use to make tiny rigging. Then they zig-zag stitched the threads into a shirt, which gives the stitches added flexibility. This thread maybe as strong and conductive as metal, but the fibers are soft and flexible, and most importantly, machine-washable. Between its strength and conductivity, this thread could have a long list of applications from military down to civilian. Check out the introduction in the video after the break.

For now, the shirt has to be pretty snug, but future garments could easily have higher concentrations of nano-threads in order to get a better signal. Good thing, because we’re still carrying around our COVID nineteen — aka the weight we’ve gained since the longest March of anyone’s life, and never liked tight shirts anyway.

What else can carbon nanotubes do? Plenty, like keep 3D prints from delaminating.

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Excel Ray Tracing With Help From C

September 28, 2021 by Al Williams 12 Comments

It isn’t news that [s0lly] likes to do ray tracing using Microsoft Excel. However, he recently updated his set up to use functions in a C XLL — a DLL, really — to accelerate the Excel rendering. Even if ray tracing isn’t your thing, the technique of creating custom high-performance Excel functions might do you some good somewhere else.

We’ve seen [s0lly’s] efforts before, and you can certainly see that the new technique speeds things up and produces a better result, which isn’t especially surprising. In addition to being faster, the new routines produce more detail.

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A Coolant Leak The Likely Culprit For Aussie Tesla Battery Bank Fire

September 28, 2021 by Jenny List 36 Comments

Followers of alternative energy technology will remember how earlier in the year a battery container at Tesla’s Megapack Australian battery grid storage plant caught fire. Lithium ion batteries are not the easiest to extinguish once aflame, but fortunately the fire was contained to only two of the many battery containers on the site.

The regulator Energy Safe Victoria have completed their investigation into the incident, and concluded that it was caused by a coolant leak in a container which caused an electrical component failure that led to the fire. It seems that the container was in a service mode at the time so its protection systems weren’t active, and that also its alarm system was not being monitored. They have required that cooling systems should henceforth be pressure tested and inspected for leaks, and that alarm procedures should be changed for the site.

When a new technology such as large-scale battery storage is brought on-line, it is inevitable that their teething troubles will include catastrophic failures such as this one. The key comes in how those involved handle them, and for that we must give Tesla and the site’s operators credit for their co-operation with the regulators. The site’s modular design and the work of the firefighters in cooling the surrounding packs ensured that a far worse outcome was averted. Given these new procedures, it’s hoped that future installations will be safer still.

You can read our original coverage of the fire here, if you’re interested in more information.

[Main image source: CFA]

Printed Adapter Puts Vintage Lens Back To Work

September 28, 2021 by Tom Nardi 16 Comments

While browsing through an antiques shop, [Nick Morganti] came across a Kodak slide projector with an absolutely massive lens hanging off the front. Nearly a foot long and with a front diameter of approximately four inches, the German-made ISCO optic was a steal for just $10. The only tricky part was figuring out how to use it on a modern DSLR camera.

After liberating the lens from the projector, [Nick] noted the rear seemed to be nearly the same diameter as the threaded M42 mount that was popular with older film cameras. As luck would have it, he already had an adapter that let him use an old Soviet M42 lens on his camera. The thread pitch didn’t match at all, but by holding the lens up to the adapter he was able to experiment a bit with the focus and take some test shots.

Encouraged by these early tests, [Nick] went about designing a 3D printed adapter. His first attempt was little more than a pair of concentric cylinders, and was focused like an old handheld spyglass. This worked, but it was quite finicky to use with the already ungainly lens. His second attempt added internal threads to the mix, which allowed him to more easily control focus. After he was satisfied with the design, he glued a small ring over the adapter so the lens could no longer be unscrewed all the way and accidentally fall out.

To us, this project is a perfect application of desktop 3D printing.[Nick] was able to conceptualize a one-of-a-kind design, test it, iterate on it, and arrive on a finished product, all without having to leave the comfort of his own home. To say nothing of the complex design of the adapter, which would be exceedingly difficult to produce via traditional means. Perhaps some people’s idea of a good time is trying to whittle a lens bayonet out of wood, but it certainly isn’t ours.

So it’s probably little surprise we’ve seen a number of similar projects over the years. From monstrous anamorphic adapters to upgraded optics for the Game Boy Camera, it seems there’s a healthy overlap between the 3D printing and photography communities.

Microwave Ovens: Need More Power? Use Lasers Instead!

September 28, 2021 by Dave Rowntree 15 Comments

You know how it is, you get in late from work, you’ve been stuck in traffic for what seems like an eternity, and you’re hungry. You reach for the microwave meal, and think, if only I didn’t have to wait that three-and-a-half minutes, 900 watts just isn’t enough power. What you need is a laser microwave, and as luck would have it, [Styropyro] has built one, so you don’t have to. No, really, don’t.

After he observed a microwave only operating on a half-wave basis, and delivering power 50% of the time, he attempted to convert it to full-wave by doubling up the high voltage transformer and rectification diodes. While this worked, the poor suffering magnetron didn’t go the full mile, and died somewhat prematurely.

Not to be disheartened, the obvious thing was to ditch the whole concept of cooking with boring old radio waves, and just use a pile of frickin’ lasers instead. Now we’re not sure how he manages to get hold of some of the parts he uses, and the laser array modules look sketchy to say the least, and to be frank, we don’t think they should be easy to get given the ridiculous beam power they can muster.

With the build completed to the usual [Styropryo] level of excellent build quality, he goes on to produce some mouthwatering delicacies such as laser-charred poptart, incinerated steak with not-really-caramelised onions and our favourite laser-popcorn. OK, he admits the beam has way too much power, really should be infrared, and way more diffuse to be even vaguely practical, but we don’t care about practicality round these parts. Who wouldn’t want the excitement of going instantly blind by merely walking into the kitchen at the wrong time?

We’ve covered a fair few microwave oven related hacks before, including a neat microwave kiln, and hacks using microwave parts, such as a janky Jacob’s ladder, but this is probably the first laser microwave we’ve come across. Hopefully the last :)

And remember kids, as [Styropyro] says in pretty much every video on his channel:

All the crazy stuff I’m about to do was done for educational purposes, in fact if you were to try any of this stuff at home, you’d probably die…

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One Where Shift Happens

September 28, 2021 by Kristina Panos 24 Comments

It’s been an exciting few weeks for me personally on the clacking front. I got a couple of new-to-me keyboards including my first one with ALPS switches, an old TI/99A keyboard with Futaba MD switches, and a couple of what are supposed to be the original Cherry switches (oh man they clack so nicely!) But enough about my keyboard-related fortuitousness, and on to the hacks and clacks!

Putting My Pedals to the Metal

I picked up this Kinesis Savant Elite triple foot pedal from Goodwill. It works fine, but I don’t like the way it’s programmed — left arrow, right arrow, and right mouse click. I found the manual and the driver on the Kinesis website easily enough, but I soon learned that you need a 32-bit computer to program it. Period. See, Kinesis never wrote an updated driver for the original Savant Elite pedal, they just came out with a new one and people had to fork over another $200 or figure something else out.

I’m fresh out of 32-bit computers, so I tried running the program in XP-compatibility mode like the manual says, but it just doesn’t work. Oh, and the manual says you can brick it if you don’t do things correctly, so that’s pretty weird and scary. It was about this time that I started to realize how easy it would be to open it up and just replace the controller with something much more modern. Once I got inside, I saw that all three switches use JST plugs and right angle header. Then I though hey, why not just re-use this set-up? I might have to make a new board, but it how awesome would it be to plug these pedals’ JSTs into my own board?

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