Posts with «classic hacks» label

Raspberry Pi Simulates the Real Analog TV Experience

If you’ve laid hands on a retro analog TV, have the restoration bug, and you plan to make the final project at least somewhat period-correct, you face a bit of a conundrum: what are you going to watch? Sure, you can serve up just about any content digitally these days, but some programs just don’t feel right on an old TV. And even if you do get suitably retro programming, streaming isn’t quite the same as the experience of tuning your way through the somewhat meager selections as we did back in the analog days.

But don’t worry — this Raspberry Pi TV simulator can make your streaming experience just like the analog TV experience of yore. It comes to us from [Rodrigo], who found a slightly abused 5″ black-and-white portable TV that was just right for the modification. The battery compartment underneath the set made the perfect place to mount a Pi, which takes care of streaming a variety of old movies and shorts. The position of the original tuning potentiometer is read by an Arduino, which tells the Pi which “channel” you’re currently tuned to.

Composite video is fed from the Pi’s output right into the TV’s video input, and the image quality is just about what you’d expect. But for our money, the thing that really sells this is the use of a relay to switch the TV’s tuner back into the circuit for a short bit between channel changes. This gives a realistic burst of static and snow, just like we endured in the old days. Hats off to [Rodrigo] for capturing everything that was awful about TV back in the day — Mesa of Lost Women, indeed! — but still managing to make it look good.

Hack a Day 20 Jun 12:00

Split Flap Display Tells Us The Word

LED and LCD displays are a technological marvel. They’ve brought the price of televisions and monitors down to unheard-of levels since the days of CRTs, but this upside arguably comes with an aesthetic cost. When everything is covered in bland computer screens, the world tends to look a lot more monotonous. Not so several decades ago when there were many sharply contrasting ways of displaying information. One example of this different time comes to us by way of this split-flap display that [Erich] has been recreating.

Split-flap displays work by printing letters or numbers on a series of flaps that are attached to a spindle with a stepper motor. Each step of the motor turns the display by one character. They can be noisy and do require a large amount of maintenance compared to modern displays, but have some advantages as well. [Erich]’s version is built out of new acrylic and MDF, and uses an Arduino as the control board. A 3D printer and CNC machine keep the tolerances tight enough for the display to work smoothly and also enable him to expand the display as needed since each character display is fairly modular.

Right now, [Erich]’s display has 20 characters on two different rows and definitely brings us back to the bygone era where displays of this style would have been prominent in airports and train stations. This display uses a lot of the basics from another split flap display that we featured a few years ago but has some improvements. And, if you’d prefer restorations of old displays rather than modern incarnations, we have you covered there as well.

Thanks to [Bob] for the tip!

Gorgeous Battery Welder Hits The Spot

Raise you’re hand if you’ve ever soldered directly to a battery even though you know better. We’ve all been there. Sometimes we get away with it when we have a small pack and don’t care about longevity. But when [Robert Dunn] needed to build a battery pack out of about 120 Lithium Ion cells, he knew that he had to do it The Right Way and use a battery spot welder. Of course, buying one is too simple for a hacker like [Robert]. And so it was that he decided to Build a Spot Welder from an old Microwave Oven and way too much mahogany, which you can view below the break.

Spot Welding leaves two familiar divots in the attached tab, which can be soldered or welded as need.

For the unfamiliar, a battery spot welder is the magical device that attaches tabs to rechargeable batteries. You’ll notice that all battery packs with cylindrical cells have a tab with two small dimples. These dimples are where high amperage electricity quickly heats the battery terminal and the tab until they’re red hot, welding them together. The operation is done and over in less than a second, well before any heat damage can be done. The tab can then be soldered to or spot welded to another cell.

One of the most critical parts of spot welding batteries is timing. While [Robert Dunn] admits that a 555 timer or even just a manual switch and relay could have done the job, he opted for an Arduino Uno with a 4 character 7 segment LED display that shows the welding time in milliseconds. A 3d printed trigger and welder handle wrap up the hardware nicely.

The build is topped off by a custom mahogany enclosure that is quite a bit overdone. But if one has the wood, the time, the tools and skills (and a YouTube channel perhaps?) there’s no reason not to put in the extra effort! [Robert]’s resulting build is almost too nice, but it’ll certainly get the job done.

Of course, spot welders are almost standard fare here at Hackaday, and we’ve covered The Good, The Bad, and The Solar. Do you have a battery welder project that deserves a spot in Hackaday’s rotation? By all means, send it over to the Tip Line!

USB Mouse Hack for Pachyderm Protection

When most of us think of seismometers, our minds conjure up images of broken buildings, buckled roads, and search and rescue teams digging through rubble. But when [Subir Bhaduri] his team were challenged with solving real world problems as frugally as possible as part of the 2020 Frugal Science course, he thought of farmers in rural India for whom losing crops due to raiding elephants is a reality. Such raids can and have caused loss of life for humans and elephants alike. How could he apply scientific means to prevent such conflicts, and do it on the cheap?

Whether inspiration came from using a computer mouse with the cursor speed turned up to “orbital velocity” is debatable, but [Subir] set forth to find out if such sensitivity could be leveraged for the seismic detection of the aforementioned elephants. His proof of concept is a fantastically frugal low cost seismograph using an optical mouse and some cheap PVC pipe and fittings.

We invite you to watch the video below the break to find out how it works. You’ll be impressed as we were by [Subir]’s practical application of engineering principles. And keep your eyes open for the beautiful magnetic damper hack. It’s a real treat!

If pontificating pesky pachyderms p-waves piques your interest, perhaps you’ll appreciate previous projects which produce data with piezo pickups and plumbing parts.

This Old Mouse: Building a USB Adapter for a Vintage Depraz Mouse

When [John Floren] obtained a vintage Depraz mouse, he started out being content to just have such a great piece of history in his possession. But if you’re like him, you know it’s not enough to just have something. What would it be like to use it?

To find out, [John] embarked on a mission to build a USB adapter for his not so new peripheral.
Originally used in very early terminals with a Unix GUI, the Depraz mouse utilizes an unusual male DE9 connector rather than the more familiar female DB9 used in RS232 serial mice. Further deviating from the norm, he found that the quadrature encoders were connected directly to the DE9 connector.

Armed with an Arduino Pro Mini and some buggy sample code, he got to work. The aforementioned buggy code was scrapped and a fresh sketch for the Arduino Pro Mini gave the Depraz mouse the USB interface it lacked. [John] also found that he wasn’t the first hardware hacker to have modified the mouse for their use. Be sure to read to the end the article to find out about the vintage surprise lurking in the mouse shell itself! A demonstration of the mouse in action can be seen in the video below the break.

Looking for a fun mouse hack? Perhaps you’d like to use your more modern USB mouse on a retro computer, or try your hand at recreating an early Apple mouse for use in modern computers.

Celebrate Spring with a DIY Vibration Sensor

Is your heaving pile of electronic parts shrinking by the day as you finish old back-burnered projects and come up with new ones? Try an old pastime that never gets old: rolling your own sensors using household objects. [Nematic!] needs a way to sense vibration for an upcoming project. Instead of spending $1 plus shipping and waiting who knows how long for a spring vibration sensor to come in the mail, they made one in a matter of minutes.

A spring vibration sensor is a simple device that can be used as a poor man’s accelerometer, or simply to detect vibration. All you need is a length of conductive wire, a 10 kΩ resistor, and a way to pick up those good vibrations. For the purposes of demonstration, [Nematic!] is using an Arduino Nano in the short build video after the break.

The wire is wound around the threads of a bolt to form a coil that’s just large enough for a resistor to fit inside. One end of the coil is connected to 5 V, and one leg of the resistor connects to an input pin. Together, they form a normally-open switch. When vibrations force the free ends of both to touch, the circuit is complete and the pin is pulled high.

If you make one of these and find the sensitivity is off, just twist up a new coil with stiffer or softer wire depending on the problem. Iterating doesn’t get much cheaper than wrapping wire around a bolt. We can’t wait to see how [Nematic!] will use this sensor. In the meantime, we’re planning to use one to detect when the dryer stops running and send a text.

Speaking of bargain basement sensors, did you know you can detect water leaks with two pennies, an aspirin, and a clothespin? These projects demonstrate the kind of ingenuity that can win you a pile of toys in our new Making Tech At Home contest, running now through July 28th, 2020.

Interactive Core Memory Shield Helps Explains The Past

[Andy Geppert] sends in his incredibly clever interactive core memory shield. 

In a great display of one hacker’s work being the base for another’s, [Andy] started out with [Jussi Kilpelainen]’s core memory shield for Arduino.  As he was playing with the shield he had a desire to “see” the core memory flipping and got the idea to add an LED matrix aligned behind the individual cores.

The first iteration worked, but it only showed the state that the Arduino believed the core memory to be in. What he really wanted was a live read on the actual state. He realized that an Adafruit Featherwing 8×8 matrix display also fits behind the core memory. Now the LEDs update based on the read state of the core memory. This allows him to flip the individual bits with a magnetic stylus and see the result. Very cool.

You can see a video of it working after the break.

Control Your Web Browser Like It’s 1969

Imagine for a moment that you’ve been tasked with developing a device for interfacing with a global network of interconnected devices. Would you purposely design a spring-loaded dial that can do nothing but switch a single set of contacts on and off from 1 to 10 times? What kind of crazy world would we have to live in where something like that was the pinnacle of technology?

Obviously, such a world once existed, and now that we’ve rolled the calendar ahead a half-century or so, both our networks and our interfaces have gotten more complex, if arguably better. But [Jan Derogee] thinks a step backward is on order, and so he built this rotary phone web browser. The idea is simple: pick up the handset and dial the IP address of the server you want to connect to. DNS? Bah, who needs it?

Of course there is the teensy issue that most websites can’t be directly accessed via IP address anymore, but fear not – [Jan] has an incredibly obfuscated solution to that. It relies on the fact that many numbers sound like common phrases when sounded out in Chinese, so there end up being a lot of websites that have number-based URLs. He provides an example using the number 517, which sounds a bit like “I want to eat,” to access the Chinese website of McDonald’s. How the number seven sounding like both “eat” and “wife” is resolved is left as an exercise to the reader.

And here we thought [Jan]’s rotary number pad was of questionable value. Still, we appreciate this build, and putting old phones back into service in any capacity is always appreciated.

Hack a Day 24 Jul 06:00
arduino  classic hacks  dial  dns  hid  homophone  ip  phone hacks  pulse  rotary  url  usb  

A Doom-esque Port To The ATmega328

Doom holds a special place as one of the biggest games of the 1990s, as well as being one of the foundational blocks of the FPS genre. Long before 3D accelerators hit the market, iD Software’s hit was being played on computers worldwide, and later spread to all manner of other platforms. [David Ruiz] decided to build a cutdown version for everyone’s favourite, the ATmega328.

Due to the limited resources available, it’s not a direct port of Doom. [David] instead took some sprites and map data from the original game, and built a raycasting engine similar to that of Wolfenstein 3D. Despite the limited memory and CPU cycles, the basic game can run at between 8-11 FPS. There are fancy dithering tricks to help improve the sense of depth, a simplified enemy AI, and even a custom text library for generating the UI.

It’s a great example of what can be done with a seemingly underpowered part. We’ve seen similar work before, with Star Fox replicated on the Arduboy. A hacker’s ingenuity truly knows no bounds.


Hack a Day 29 Jun 12:00

Arduino Shield Makes Driving Nixies Easy

Nixie tubes are adored by hackers across the world for their warm glow that recalls an age of bitter nuclear standoffs and endless proxy wars. However, they’re not the easiest thing to drive, requiring high voltages that can scare microcontrollers senseless. Thankfully, it’s possible to score an Arduino shield that does the heavy lifting for you.

The HV supply is the heart of any Nixie driver.

The shield uses HV5812 drivers to handle the high-voltage side of things, a part more typically used to drive vacuum fluorescent displays. There’s also a DHT22 for temperature and humidity measurements, and a DS3231 real time clock. It’s designed to work with IN-12 and IN-15 tubes, with the part selection depending on whether you’re going for a clock build or a combined thermometer/hygrometer. There’s also an enclosure option available, consisting of two-tone laser etched parts that snap together to give a rather sleek finished look.

For those looking to spin up their own, code is available on Github and schematics are also available. You’ll have to create your own PCB of course, but there are guides that can help you along that path. If you’re looking to whip up a quick Nixie project to get your feet wet, this might just be what you need to get started. Of course, you can always go straight to hard mode, and attempt a functional Nixie watch. Video after the break.