Reverse Engineering The Weather Channel’s Magic

March 14, 2021 by Tom Nardi 32 Comments

For American readers of a certain age, Local on the 8s likely holds a special spot in your heart. The program, once a staple of The Weather Channel, would provide viewers with a text and eventually graphical depiction of their local forecast set to some of the greatest smooth jazz ever heard outside of an elevator. In the days before smartphones, or even regular Internet access for that matter, these broadcasts were a critical part of planning your day in the 1980s through to the early 2000s.

Up until recently the technical details behind these iconic weather reports were largely unknown, but thanks to the Herculean efforts of [techknight], the fascinating engineering that went into the WeatherSTAR 4000 machines that pumped out current conditions and Shakin’ The Shack from CATV distribution centers all over the US for decades is now being documented and preserved. The process of reversing the hardware and software has actually been going on for the last couple of years, but all those juicy details are now finally going to be available on the project’s Hackaday.IO page.

It all started around Christmas of 2018, when an eBay alert [techknight] had configured for the WeatherSTAR 4000 finally fired off. His offer was accepted, and soon he had the physical manifestation of Local on the 8s in his own hands. He’d reasoned that getting the Motorola MC68010 machine working would be like poking around in a retrocomputer, but it didn’t take long for him to realize he’d gotten himself into a much larger project than he could ever have imagined.

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Keep Cool With This Open Source AVR Fan Controller

March 12, 2021 by Tom Nardi 12 Comments

We’ve all got projects kicking around that we haven’t had time to document for our own purposes, let alone expose to the blinding light of the Internet. There are only so many hours in a day, and let’s face it, building the thing is a lot more fun than taking pictures of it. It took [Matthew Millman] the better part of a decade to combine everything he’s learned over the years to finally document the definitive version of his open source intelligent fan controller, but looking at the final result, we’re glad he did.

At the heart of this board is an ATmega328P, but don’t call it an Arduino. [Matthew] makes it very clear that if you want to hack around with the code for this project, you’re going to need to not only have a programmer for said chip, but know your way around AVR-GCC. He’s provided pre-built binaries for those content to run with the default settings, but you’ve still got to get it flashed onto the chip yourself. The project is designed to use the common DS18B20 temperature sensor, and as an added bonus, the firmware can even check if yours is a bootleg (spoilers: there’s an excellent chance it is).

Arguably the most interesting feature of this fan controller is its command line interface. Just plug into the serial port on the board, open your terminal emulator, and you’ll have access to a concise set of functions for querying the sensors as well as setting temperature thresholds and RPM ranges for the fans. There’s even a built-in “help” function should you forget a command or the appropriate syntax.

Originally [Matthew] developed this project as a way to control multiple fans inside of a PC case, but naturally, things have changed quite a bit since those early days. While today there’s no shortage of fancy controllers that can handle throttling an array of fans based on the internal temperature of your rig, there’s still something to be said for rolling your own solution. More importantly, there’s certainly other potential uses for a fully open source programmable fan controller.

Complicated And Useless Cancel Each Other Out

March 3, 2021 by Brian McEvoy 11 Comments

We all know what it means to procrastinate, but what about actively spending time building a useless machine? You have undoubtedly seen the ornamental boxes with a tempting little toggle switch on the top. When you inevitably flip the switch, an actuator pops out from one half of the enclosure with the sole purpose of undoing its own power switch. [Paz Hameiri] took it a step further by adding some [Rube Goldberg] flavor, and with the help of a microcontroller, his levers take their sweet time powering themselves down. (Video after the break.)

We didn’t find any code or diagrams for the project, but if you know the useless machine’s internals, it shouldn’t be any trouble to recreate one for your desk. The most significant design factor is that the switches. Their contacts must be wired in parallel so that the controller has power as long as one is active. How would you spice up the useless machine?

Even though these are called useless machines, they serve the purpose of decoration, conversation-starting, or a way to show off your woodworking and programming skills.

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SVG To Gerber, Without The Pain

March 1, 2021 by Jenny List 10 Comments

We’ve all marveled at the high quality PCB artwork used within the #BadgeLife and other communities to produce eye-catching designs, but those of you who have dipped your toes in the PCB artwork water will know that it’s hardly an easy process. [Jaseg] may have an answer though with gerbolyze, his software for processing SVG files into Gerber layers or KiCAD footprints.

His impetus for building it came from disappointing experience with other scripts that simply tried to rasterise any SVG they were given, or didn’t fully support the complete SVG spec. It’s designed for minimal preprocessing, allowing for as streamlined a process as possible. It includes a bitmap vectoriser to handle everything that can be thrown at it, and the GitHub repository has full instructions including examples of the output for different settings.

This is the latest in a long progression of enhancements to the PCB art process, but it’s not by any means the first time we’ve ventured down this path. In particular [Brian Benchoff] did a lot of work on the production of multi-colour PCBs.

Sounding The Humble LED

February 27, 2021 by Kerry Scharfglass 22 Comments

Here at Hackaday we’re no strangers to the colorful glow of LEDs. But what if there was more to appreciate beneath the surface? Back in 2011 [Windell] over at Evil Mad Scientist dug into a certain variety of LED and discovered they had a song to sing.

Over the last couple decades, you’ve likely encountered the flickering “candle flame” variety of LED. Often found embedded in small plastic candle simulacra they are shaped like typical through hole “gumdrop” style LEDs, but pack some extra magic which causes them to flicker erratically. Coupled with a warm white color temperature the effect isn’t entirely dissimilar to the flickering of a candle flame.

To the Hackaday reader (and [Windell]) the cause of the flickering may be fairly clear, there is an IC embedded in the lens of the LED. See photo at top for an example of how this might look, helpfully magnified by the lens of the LED itself. Looking through the lens the captive die is visible, as well as the bond wires connecting it to the legs and light emitting diode itself. [Windell]’s observation is that together this assembly makes for a somewhat strange electrical component; from the perspective of the circuit it appears to randomly vary the current flowing through the LED.

He includes two interesting demos. One is that by attaching the flickering LED to a BJT he can turn it into a current amplifier and successfully drive a much more powerful 1W LED with the same effect. The other is that with the power of the amplifier the same flickering LED can drive a buzzer as well. The effect is surprisingly pleasant, though we’d hesitate to call it musical.

For a more recent example of a similar phenomenon with a very different sound, check out out [Emily Velasco]’s playback of a similarly constructed RGB color changing LED, embedded below. We’ve seen optical tools used to decode LED flickers into data streams, but not for audio playback! We have also covered some LED flicker reverse engineering that spills more of the mystery sealed up in these specialized diodes.

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Taking A Capacitor Microphone To The Next Level

February 24, 2021 by Jenny List 13 Comments

There was a time when a microphone for most people was a cheap plastic affair that probably came for free with their sound card, but in the age of pandemic video streaming no desktop is complete without a chunky model that looks for all the world as though it escaped from a studio. Few people make their own microphones, so the work of [DJJules] in building very high quality condenser microphones is a particularly fascinating read.

A condenser microphone is a capacitor in which one plate is formed by a conductive diaphragm. A bias voltage is supplied to the diaphragm via a resistor, and since the charge on the plate remains constant as its capacitance changes with the sound vibrations, the voltage on the capacitor changes accordingly. This is picked up by a high impedance buffer and from there fed to a normal microphone input. This Instructable uses a commercial condenser microphone capsule, and takes the reader through generating the bias voltage for it before describing the op-amp buffer circuit.

The most interesting part comes at the end, as we’re shown how the sensitivity pattern of a dual-microphone array can be tuned to be omnidirectional, cardoid, or figure-of-eight. This is probably the norm among audio engineers, but we rarely see this sort of insight in our community. We may never build a microphone of our own, but it’s fascinating to see this one from the ground up in the video below the break.

If you’re confused about the difference between a condenser microphone and the more common electret condenser microphone, we have published a guide to that topic. Continue reading “Taking A Capacitor Microphone To The Next Level” →

Custom 3D Printed Vitamins Are Just A Few Clicks Away

February 18, 2021 by Tom Nardi 39 Comments

It’s recently come to our attention that a company by the name of Nourished has carved out a niche for themselves by offering made-to-order gummy vitamins produced with their own custom designed 3D printers. Customers can either select from an array of pre-configured “stacks”, or dial in their own seven layers of gelatinous goodness for a completely bespoke supplement.

Now we can’t vouch for whether or not taking a custom supplement like this is any better than just popping a traditional multi-vitamin, but we’ll admit the hardware Nourished has developed is pretty interesting. As briefly seen in the video after the break, large syringes are filled with the seven different vitamin suspensions, and then loaded into what appears to be a heated chamber for extrusion. This is not unlike other food-grade 3D printers we’ve seen, such as the Cocoa Press.

It looks like all of the syringes are being depressed simultaneously with a plate and a pair of beefy lead screws, so it seems the order in which the layers are placed down must be different for each nozzle. A blog post on the company’s site from early last year shows a wildly different machine being used to produce the vitamins, so either their core technology is changing rapidly, or perhaps the printer being used depends on whether they’re running off the customized stacks versus the standard formulations.

Interestingly, this is very similar to a concept floated by the U.S. Army’s Combat Feeding Directorate (CFD) back in 2014. They reasoned that a 3D printer could be used to produce meal bars that were customized for each soldier’s personal nutritional needs. Being largely impractical for the battlefield, the program didn’t get very far. But thanks to consumers who are willing to pay the premium that Nourished is charging for this service, it seems the idea has turned into a lucrative business model.

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