Year: 2020

Gorgeous Clock, And Not A Line Of Code In Sight

March 4, 2020 by 41 Comments

[Harry] dropped us a note to let us know about his completed CMOS clock project, and we’re delighted that he did because it’s gorgeous. It’s a digital clock satisfyingly assembled entirely from hardware logic, without a single line of code. There are three main parts to this kind of digital clock: ensuring a stable time base, allowing for setting the time, and turning the counter outputs into a numerical display.

Keeping accurate time is done with a 32.768 kHz crystal, and using CMOS logic to divide that down to a 1 Hz square wave. From there, keeping track of hours and minutes and seconds is mostly a matter of having counters reset and carry at the appropriate times. Setting the clock is done by diverting the 1 Hz signal so that it directly increments either the hours or minutes counter. The counter values are always shown “live” on six 7-segment displays, which makes it all human-readable.

The whole thing is tastefully enclosed in a glass dome which looks great, but [Harry] helpfully warns prospective makers that such things have an unfortunate side effect of being a fingerprint magnet. Schematics and design files are provided for those who want a closer look.

This clock uses a crystal and divider, but there’s another method for keeping accurate time and that’s to base it off the alternating current frequency of power from the grid. Not a bad method, albeit one that depends on being plugged into the wall.

Write Once, Run Everywhere: Cross-Platform Programming Done Right

March 4, 2020 by 58 Comments

One of the goals of programming languages back in the 1950s was to create a way to write assembly language concepts in an abstract, high-level manner. This would allow the same code to be used across the wildly different system architectures of that era and subsequent decades, requiring only a translator unit (compiler) that would transform the source code into the machine instructions for the target architecture.

Other languages, like BASIC, would use a runtime that provided an even more abstract view of the underlying hardware, yet at the cost of a lot of performance. Although the era of 8-bit home computers is long behind us, the topic of cross-platform development is still highly relevant today, whether one talks about desktop, embedded or server development. Or all of them at the same time.

Let’s take a look at the cross-platform landscape today, shall we?

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Dog-Harnessing The Power Of Walkie Talkies

March 4, 2020 by 12 Comments

[javier.borquez] likes to take his dog to the hang out at the dog park around dusk. But once the sun goes down and [Rusio]’s off the leash, running amok with the other dogs, it’s almost impossible to keep track of him.

Sure, there are probably glow-in-the-dark or lighted collars out there, but if you go commercial, chances are good that someone else’s dog will be wearing the same thing. Besides, what’s the fun in buying something that you can do a better job making yourself? With this dog distance indicator harness, you don’t even have to program anything. Instead, it uses a cheap pair of modified walkie talkies to show green LEDs on the harness while the dog is in range, and red when it isn’t.

Although [javier]’s pupper is the best pupper yes he is, [Rusio] can’t be expected to hold down the button and bark his location. His walkie talkie uses a 555-based frequency generator and a glued-down button to speak at 1 kHz.

Over in [javier]’s walkie, there’s a resistor in place of the speaker to keep the talkie parts working. There’s also a half-wave bridge rectifier that charges a capacitor when [Rusio] is within range, and a resistor that drains it when he’s outside the 6-8 meter range. The rectifier’s output goes to a second 555 set up as a Schmitt trigger, which tells a transistor to turn the red LEDs on instead.

If you got stuck on the idea of hearing your dog talk to you over distances, here’s a Bluetooth Babelfish collar.

Wire Wrapping Skills Put To Use For Sign Making

March 4, 2020 by 20 Comments

We don’t see many wire wrapped circuits these days, and you could be forgiven for thinking it was nearly a lost art at this point. But that doesn’t mean the technique can’t be applied elsewhere. [MiHu-Works] recently wrote in to share a sign they recently made for a client’s restaurant that looks an awful lot like the back panel of a homebrew computer to us.

Before you get a chance to scroll down and complain about it in the comments, we admit this one is fairly deep into the crafts side of the spectrum. But it’s also a gorgeous piece that we’d be happy to hang up in the hackerspace, so we don’t care. There might not be any angry pixies zipping around through all that lovingly wrapped copper wire, but it certainly feels like you’re looking at the internals of some complex machine.

To make it, [MiHu-Works] first printed out the lettering on paper and put it on the wood to serve as a guide. Roofing nails were then driven into the wood to create the outline of the text. A simple tool made from a forked piece of wood was placed under the head of each nail as it was hammered in to make sure the depth was consistent. It also made sure there was adequate room underneath to wrap the copper wires through them. Then it was time for the wrapping…so much wrapping. (Who is going to come through with the robot to do this?)

A few years back we asked the Hackaday readers if they thought the days of wire wrapped circuits were over. It generated a lot of discussion and interesting ideas, but looking at projects like this, perhaps we were asking the wrong question.

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Stop ‘n Go DUPLO

March 3, 2020 by 8 Comments

[beshur]’s 2-year-old is obsessed with transportation, so he lifted a few DUPLO blocks from the bin and made this toy traffic light as a birthday present. Hey, might as well get him used to the realities of traffic, right? It also makes for a good early hacker lesson: why buy something when you can make it yourself?

The traffic pattern is determined by an Arduino Nano V3 situated inside the carved-out rear block. There’s a push button on the side in case there’s a spill and the lights need to go blinking red until the issue is dealt with. Instead of trying to solder everything in situ and risk melting the plastic, [beshur] dead-bugged the LEDs and resistors to the Nano with a helping hands and then worked everything into the case. The 5mm LEDs fit perfectly into the drilled-out posts of a second block and produce a nice, soft glow. Proceed with caution and check it out after the break.

Of course, plastic building blocks can do real work, too. This LEGO chocolate pantograph is pretty sweet.

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A(nother) Minimalist Window Manager

March 3, 2020 by 31 Comments

For however many Linux distributions there are to choose from, there are perhaps even more window managers that can be paired with them, and some have dramatically different features than the X window systems that most of us are familiar with. There’s a rabbit hole to fall down, as with most Linux-related topics, but while this tiling window manager from [caoluin], called sara, adds to the cacophony, it’s also representative of any pet project that lets us take a deep dive into something personally interesting.

What started as a desire to revive an abandoned window manager called catwm eventually evolved into a fork of sorts of another popular window manager called dwm. dwm is used as a basis or as building blocks for many other window managers, and while [caoluin] was writing sara he found that many of the solutions he found converged on the same things that dwm had already implemented. In a way, it’s reassuring if your solutions are similar to tried-and-true methods already in use. For other things he found interesting solutions, and other features that dwm has he found to be unnecessary and removed them.

Does the world need another window manager? Probably not. But we can all appreciate building something from scratch, just to see how it really works under the hood. As far as that goes, we’d consider sara a success for [caoluin], and if you’re really interested in window managers then you can take a look at his Github page or one of the more esoteric window managers we’ve seen.

DIY Large Format Book Press Puts On The Pressure

March 3, 2020 by 13 Comments

For those in the audience who aren’t well versed in wrangling dead trees, a large press with a lot of clamping pressure can be used for binding books or printing. It can even be used to squeeze the water out of homemade paper. It’s an important tool for anyone looking to make or repair books, but they also tend to be fairly expensive. Which is why [Paul] decided to make his own.

Despite the preconceived notions you might have about the type of guy who binds his own books, it seems like [Paul] is a rather modern fellow. He actually designed the press in CAD and made many of the parts for it on his CNC router. That’s not strictly required, though we do think cutting out the hole for the monstrous lead screw nut would be a bit tricky if you had to do it by hand. But beyond that, the design is pretty straightforward and the video after the break provides a very clear step-by-step guide on how to build your own.

In the past we’ve seen how a similar, if much smaller, book press can be used to make bound books of all those PDFs littering your computer. These sort of projects are getting more rare in an increasingly paperless world, but we always like to see people keeping the old ways alive. If the revolution comes and we end up needing to publish Hackaday on hand-pressed paper, we’ll know who to call.

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