Vintage Gauges Turned Classy Weather Display

August 8, 2020 by Tom Nardi 4 Comments

It’s always good to see old hardware saved from the junk pile, especially when the end result is as impressive as this analog gauge weather display put together by [Build Comics]. It ended up being a truly multidisciplinary project, combing not only restoration work and modern microcontroller trickery, but a dash of woodworking for good measure.

Naturally, the gauges themselves are the real stars of the show. They started out with rusted internals and broken glass, but parts from a sacrificial donor and some TLC from [Build Comics] got them back in working order. We especially like the effort that was put into making the scale markings look authentic, with scans of the originals modified in GIMP to indicate temperature and humidity while retaining the period appropriate details.

To drive the 1940s era indicators, [Build Comics] is using an Arduino Nano and a DHT22 sensor that can detect temperature and humidity. A couple of trimmer pots are included for fine tuning the gauges, and everything is mounted to a small scrap of perfboard hidden inside of the custom-made pine enclosure.

This is hardly the first time we’ve seen analog gauges hooked up to modern electronics, but most of the projects are just that: modern. While the end look might be somewhat polarizing, we think maintaining the hardware’s classic style was the right call.

Just Who Makes Tubes These Days?

August 6, 2020 by Jenny List 104 Comments

For most of us, electronic technology comes in the form of solid state devices. Transistors, integrated circuits, microcontrollers. But for the first sixty years or so of the field existing, these devices either hadn’t been invented yet or were at too early a stage in their development to be either cost-effective, or of much use. Instead a very different type of electronic component ruled the roost, the vaccum tube.

A set of electrodes in an evacuated glass envelope whose electrical properties depended on the modulation of the flow of electrons through them, these were ubiquitous in consumer electronics up until the 1960s, and clung on in a few mass-market applications even as far as the mid 1970s. As cheaper and more versatile semiconductors superseded them they faded from electronic parts catalogues, and the industry that had once produced them in such numbers disappeared in favour of plants producing the new devices. Consumer products no longer contained them, and entire generations of engineers grew up never having worked with them at all. If you were building a tube amplifier in the early 1990s, you were a significant outlier. Continue reading “Just Who Makes Tubes These Days?” →

Mold-Making Masterclass In Minutes

August 5, 2020 by Kristina Panos 11 Comments

Making silicone molds seems easy, but there are a lot of missteps to be made along the way that can mean the difference between a great, reusable mold, and one that’s a sad waste of silicone. If you’re helpless to know the difference, then check out [Eric Strebel]’s 9-minute masterclass teaser video on making a two-part mold for resin casting, which is also embedded below.

Even if you already know how to do this, there’s probably a good tip in here somewhere. One of them being that you should always pour your silicone from one place and let it coat the piece being copied. Otherwise, there might be lines on the mold. Another tip is for DIY mold release made from petroleum jelly thinned with naphtha.

Our favorite tip has to do with the way [Eric] makes this a reusable two-part mold, which is more akin to injection molding. To pour silicone for the second part and get it to separately nicely, [Eric] uses sprues made out of resin rods that were cast inside of drinking straw molds. These he chamfers against a belt sander to minimize the contact with the cast part, which makes them a snap to break off. [Eric] says this is just the beginning, and there are more videos to come that will break down the steps.

There’s more than one way to make a mold, especially for casting in metal. We’ve seen everything from 3D-printed molds to kinetic sand.

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CBS Announces Functional Tricorder Replica For 2021

July 22, 2020 by Tom Nardi 61 Comments

It’s taken 54 years, but soon, you’ll finally be able to buy a fully-functional version of the tricorder from Star Trek. Announced on the official website for the legendary sci-fi franchise, the replica will be built by The Wand Company, who’ve previously produced a number of high-quality official Star Trek props as well as replicas for Doctor Who and the Fallout game series.

Admittedly, we’re not sure what a “fully-functional tricorder” actually is, mainly because the various on-screen functions of the device were largely driven by whatever bind Kirk and Spock managed to find themselves in that week. But the announcement mentions the ability to scan radio frequencies, pull in dynamic data from environmental sensors, and record audio. The teaser video after the break doesn’t give us any more concrete information than the announcement, but it does seem to confirm that we’ll be viewing said data on the device’s iconic flip-up display.

Now as the regular Hackaday reader knows, fans have been building extremely impressive “functional” tricorders for some time now. Unlike the sleek 24th century versions seen in Star Trek: The Next Generation, the original tricorder prop was rather clunky and offers plenty of internal volume for modern goodies. Cramming a Raspberry Pi, LCD, and a bunch of sensors into an inert replica is a relatively approachable project. So it will be interesting to see how the official version stacks up to what’s already been done by intrepid hackers and makers.

The official tricorder won’t be available until summer of 2021, but you can sign up to be notified when it’s your turn to beam one up. While the $250 USD sticker price might keep the more casual Trekkers at bay, it’s actually a bit cheaper than we would have assumed given the amount of time and money we’ve seen fans put into their own builds.

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Upgrading The RAM In A 25 Year Old Oscilloscope

July 19, 2020 by Tom Nardi 25 Comments

From reading his extensive write-ups on the subject, there’s one thing we know for sure: [Tom Verbeure] loves his Tektronix TDS 420A oscilloscope. While it might be older than some of the people reading this, it’s still an impressive piece of hardware with more than enough bells and whistles to keep the average hacker occupied. Especially if you’re willing to perform some hardware modifications.

Note the battery to retain calibration data.

[Tom] already knew how to tickle the scope into unlocking software features, a process not unlike what we’ve seen done on more modern scopes. But there’s only so far you can get by toggling software flags.

Some of the more advanced features that are turned off in the firmware actually need additional hardware to function. Simply bumping the sample points to 120,000 in software wasn’t enough, the scope actually needs the memory to hold them in.

Now logically, if there’s a software option to increase the number of samples, there must be a hardware upgrade that goes along with it. Sure enough, [Tom] found there were 6 open spots next to the scope’s existing M5M51008 static RAM ICs.

As luck would have it the chips are still available, albeit from a different manufacturer and a bit faster than the original parts. Digikey wouldn’t sell fewer than 100 of them, but UTSource was happy to sell him 10. In this case, the parts were cheaper than the shipping cost. Installation was about as straightforward as it gets, though [Tom] does note that he had to keep the board powered up during the operation or else the scope would have lost its calibration data.

Squeezing more features out of modern scopes like the Rigol DS2072A just takes a USB cable and some software. Sometimes it’s only a matter of tapping in a code. But we certainly appreciate [Tom] putting in a little extra effort to get the most out of this classic piece of hardware.

A Tin Can Modem, Just For Fun

July 18, 2020 by Dan Maloney 9 Comments

Anyone old enough to fondly recall the “bleep-burp-rattle” sequence of sounds of a modem negotiating a connection over a phone line probably also remembers the simple “tin-can telephone” experiment, where a taut string transmits sound vibrations from the bottom of one tin can to another. This tin can modem experiment puts both of those experiences together in a single project.

As [Mike Kohn] notes, this project was harder than it would seem that it should be. He actually had a much harder time getting the tin can phone part of the project optimized than getting the electronics sorted out, resulting in multiple tries with everything from the canonical tin cans to paper coffee cups before eventually settling on a pair of cardboard nut cans, the kinds with the metal bottoms. Linked together with a length of kite string — dental floss didn’t work — [Mike] added a transmitter on one end and a receiver on the other.

The transmitter used an ATtiny 2313 and everyone’s favorite audio amplifier, the LM386, while the receiver sported an electret mike preamp board, an LM566 tone decoder, and an MSP430 microcontroller. The modulation scheme was as simple as possible — a 400 Hz tone whose length varies whether it’s a one or a zero, or a stop or start bit. Connected to a pair of terminal programs, [Mike] was able to send his name over the ~~wire~~ string at what he calculates to be six or seven baud.

This project has all the hallmarks of lockdown boredom, but we don’t care because it’s good fun and a great learning opportunity, particularly for the young ones. There’s plenty of room for optimization, too — maybe it could even get fast enough for the Hackaday Retro 300-baud challenge.

Continue reading “A Tin Can Modem, Just For Fun” →

Reverse Engineering Teaches An Old Scope New Tricks

July 18, 2020 by Adil Malik 8 Comments

[PMercier] clearly loves his old Tektronix TDS3014 scope, which did however lack essentially modern connectivity such as an Ethernet port for control and a USB port for a convenient way to capture screenshots. So he decided to do some in-depth reverse engineering and design his own expansion card for it. The scope already has an expansion port and an expansion card, but given this model was first released in 1998, purchasing an OEM part was not going to be an option.

They don’t make ’em like they used to. Test equipment is today is built to last a decade — but usually lives on much longer. This is certainly true for the previous generations of kit. It’s no surprise that for most of us, hand-me-downs from universities, shrewd eBay purchasing, and even fruitful dumpster dives are a very viable way to attain useful and relevant test equipment. Now, while these acquisitions are more than adequate for the needs of a hobbyist lab, they are admittedly outdated and more to the point, inaccessible from a connectivity and communication standpoint. A modern lab has a very high degree of automated data acquisition and control over ethernet. Capturing screen dumps on a USB is a standard feature. These modern luxuries don’t exist on aging equipment conceived in the age of floppy disks and GPIB.

Continue reading “Reverse Engineering Teaches An Old Scope New Tricks” →