Hacking Film Processing With Coffee

Years ago, doing your own darkroom work was the only way to really control what your pictures looked like. In those days, coffee was what kept you going while you mixed another batch of noxious chemicals in the dark and fumbled to load a tank reel by feel. But did you know that you can process black and white film with coffee? Not just coffee, of course. [Andrew Shepherd] takes us through the process using what is coyly known as Caffenol-C.

Apparently, the process is not original, but if you’ve ever wanted to do some film developing and don’t want exotic and dangerous chemicals, it might be just the ticket. The ingredients are simple: instant coffee, washing soda, water and –optionally — vitamin C powder. If nothing else, all of this is safe to pour down your drain, something you probably aren’t supposed to do with conventional developers that contain things like formaldehyde and methyl chloroform.

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A CMOS Ring Modulator Pedal

Earlier this year, we featured an unusual radio receiver that took the very traditional superhetrodyne design and implemented it in an unexpected fashion without any inductors, using instead a combination of 74HC logic chips and op-amps. Its designer [acidbourbon] remarks that the circuit bears a striking resemblance to a ring modulator,so has taken it down that path by producing a 74HC based ring modulator guitar pedal.

In both circuits, a 74HC4046 phase-locked loop chip serves as an oscillator, driving a 74HC4051 analogue switch chip that performs the mixer task. The extra-op-amp filter and demodulator circuitry from the radio is omitted, and the oscillator frequency moved down to the audio range. The result can be heard in the video, and we probably agree with him that it’s not quite the same as a classic ring modulator. This lies in the type of mixer, the diodes used in a traditional circuit have a forward voltage to overcome before they start or end conducting, while the CMOS switch chip does so immediately on command.

The 4000 series CMOS and their descendants are a fascinating family with many unexpected properties that our colleague Elliot Williams has gone into detail with for his Logic Noise series. Meanwhile take a look at our coverage of the original radio.

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Tiny 3D Printed Magnets Show Patterns

You normally associate a double helix with DNA, but an international team headquartered at Cambridge University used 3D printing to create magnetic double helixes that are about a 1,000 times smaller than a human hair. Why do such a thing? We aren’t sure why they started, but they were able to find nanoscale topological features in the magnetic field and they think it will change how magnetic devices work in the future — especially magnetic storage devices.

In particular, researchers feel this is a step towards practical “racetrack” memory that stores magnetic information in three dimensions instead of two and offer high density and RAM-like access times. You can read the full paper if you want the gory details.

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When Hacking And Biosensing Collide

[Prof. Edwin Hwu] of the Technical University of Denmark wrote in with a call for contributions to special edition of the open-access scientific journal Biosensors. Along the way, he linked in videos from three talks that he’s given on hacking consumer electronics gear for biosensing and nano-scale printing. Many of them focus on clever uses of the read-write head from a Blu-ray disc unit (but that’s not all!) and there are many good hacks here.

For instance, this video on using the optical pickup for the optics in an atomic force microscope (AFM) is bonkers. An AFM resolves features on the sub-micrometer level by putting a very sharp, very tiny probe on the end of a vibrating arm and scanning it over the surface in question. Deflections in the arm are measured by reflecting light off of it and measuring their variation, and that’s exactly what these optical pickups are designed to do. In addition to phenomenal resolution, [Dr. Hwu’s] AFM can be made on a shoestring budget!

Speaking of AFMs, check out his version that’s based on simple piezo discs in this video, but don’t neglect the rest of the hacks either. This one is a talk aimed at introducing scientists to consumer electronics hacking, so you’ll absolutely find yourself nodding your heads during the first few minutes. But then he documents turning a DVD player into a micro-strobe for high speed microfluidics microscopy using a wireless “spy camera” pen. And finally, [Dr. Hwu’s] lab has also done some really interesting work into nano-scale 3D printing, documented in this video, again using the humble Blu-ray drive, both for exposing the photopolymer and for spin-coating the disc with medium. Very clever!

If you’re doing any biosensing science hacking, be sure to let [Dr. Hwu] know. Or just tear into that Blu-ray drive that’s collecting dust in your closet.

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Santa’s Beard-Combing Robot

Working all year long, herding elves and fabricating toys for all the good boys and girls; it takes dedication. It’s only natural that one could fall behind in beard care, right? This year, [Norbert Zare] saves Christmas with his beard-combing robot.

OK, this is much more of a shitty robot in the [Simone Giertz] school of wicked funny machines than it is a serious robotics project. But props to [Norbert] for completeness — the code that wiggles the two servos that get the job (almost) done is even posted up on GitHub.

Check out the video below the break. Ho ho ho!

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Hackaday Podcast Super-Short Holiday Edition

It’s a holiday weekend, and the Podcast is taking a break until 2022. But that can’t stop Hackaday’s Elliot Williams from giving out a t-shirt to the winner of last week’s What’s That Sound.

It’s the shortest Podcast ever!

 

Direct download (5 MB)

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The Legend Of Zelda: Decompiled

Keeping source code to programs closed is something that is generally frowned upon here for plenty of reasons. Closed source code is less secure and less customizable, but unfortunately we won’t be able to convince everyone of the merits of open source code any time soon. On the other hand, it is possible to decompile some of those programs whose source remains behind locked doors in an attempt to better understand that code, and one of the more impressive examples of that of late is this project which has fully decompiled The Ocarina of Time.

To get started with the code for this project, one simply needs to clone the Git repository and then use a certain set of software tools (depending on the user’s operating system) to compile the ROM from the source code. From there, though, the world is your rupee-filled jar. Like we’ve seen from other decompiled games, any number of enhancements to the original game can be made including increasing the frame rate, improving the graphics, or otherwise adding flourishes that wouldn’t otherwise be there.

The creators of this project do point out that this is still a work-in-progress as only one of the 18 versions have been completed, but the fact that the source code they have been able to decompile builds a fully-working game when recompiled speaks to how far along it’s come. We’ve seen similar processes used for other games before that also help to illustrate how much improvement is possible when re-writing old games from their source code.

Thanks to [Lazarus] for the tip!

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