Tell Time Like It’s 1960 With This All-Transistor Digital Clock

April 9, 2020 by 44 Comments

When you’ve got time on your hands, doing something the hard way can be therapeutic. Not that the present situation and the abundance of free time that many are experiencing has anything to do with [Leo Fernekes] all-transistor digital clock build, which he started a year ago with his students. But if you’ve got time to burn, this might be a good way to do it.

[Leo] says one of his design goals with this clock was to do it with the technology commercially available in 1960, which means relying completely on discrete components. And he and his students managed to do just that, with the exception of the seven-segment displays, which were built from the LED filaments from some modern light bulbs. Everything else, though, is as old school as it gets, and really underscores all the complexity that gets abstracted away from timekeeping with modern chips. The video below covers each module in detail, from the Schmitt trigger that cleans up the 50-Hz line frequency to the ring counters and diode matrices used to drive the display. We found the analog stair step dividers used to bring the line frequency down to a more usable pulse train particularly interesting. That clever bit of engineering saved 10 transistors over what would be required for traditional flip-flop dividers.

There’s a lot to learn from this design, and the execution is great too – we’re suckers for Manhattan-style builds, of course. Hats off to [Leo] and his lucky students on a great build.

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Nixie Clock Turns Boombox

April 7, 2020 by 12 Comments

With all the Nixie Clock projects out there, it is truly difficult to come up with something new and unique. Nevertheless, [TheJBW] managed to do so with his Ultimate Nixie Internet Alarm Clock (UNIAC) which definitely does not skimp on cool features.

Although the device does tell time, it is actually a portable boombox that streams music from Spotify using a Raspberry Pi Zero running Mopidy. The housing made from smoked acrylic, together with the IN-12A Nixie Tubes, an IN-13 VU meter, and illuminated pushbuttons give this boombox kind of a 70s/90s mashup retro look. The acrylic housing is special since it consists of only two plates which were bent into shape, resulting in smooth edges in contrast to the often used finger or T-slot design.

For his project [TheJBW] designed a general-purpose Nixie display that can not only show time and date but also the elapsed or remaining track time. He also came up with a Python generated artificial voice that reads you the current playlist. The only problem [TheJBW] has run into was when trying to design a suitable battery system for the device, as the high current draw during start-up can easily cause brownouts. Due to time constraints, he ended up with a MacGyver-style solution by taping a 12 V battery pack from Amazon to the back of the unit.

Among the large variety of Nixie projects we don’t think we have ever seen them in an audio player before except for some attempts of using them as an amplifier. However, it is known that IN-13 tubes make a great VU meter.

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Cesium Clock Teardown, Or Quantum Physics Playground

March 25, 2020 by 20 Comments

Half the fun of getting vintage test equipment is getting to open it up. Maybe that’s even more than half of the fun. [CuriousMarc] got an HP 5061A Cesium clock, a somewhat famous instrument as the model that attempted to prove the theory of relativity. The reason? The clock was really the first that could easily be moved around, including being put on an airplane. You can watch the video below.

According to the video, you can simplify special relativity to saying that time slows down if you go fast — that is known as time dilation. General relativity indicates that time slows down with increasing gravity. Therefore, using airborne Cesium clocks, you could fly a clock in circles high up or fly at high speeds and check Einstein’s predictions.
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LEGO My Colorful Custom Clock

March 23, 2020 by 7 Comments

[Sofia] spent a lot of time looking around for the perfect LEGO clock. Eventually, she realized that the perfect LEGO clock is, of course, the one you build yourself. So if you find yourself staring at the same old boring clock, contemplating time and the meaning of time itself, why not spend some time making a new timepiece?

You probably already had the LEGO out (no judgment here). This build doesn’t take a whole lot of building blocks — just a microcontroller, a real-time clock module, some LED matrices to display the digits, shift registers if they’re not already built into the matrices, and a pair of buttons for control. [Sofia] used an Arduino Nano, but any microcontroller with enough I/O ought to work. Everybody needs a colorful new way to block out their time.

We love the way this clock looks, especially the transparent panels in front of the LED panels. Given the countless custom pieces out there from all the special sets over the years, we bet you could come up with some really interesting builds.

If your kid is too young to tell time, try building a kid-friendly clock to give them segmented structure.

Via r/duino

Ask Hackaday: What Should We Be Doing During Coronavirus Lockdown?

March 23, 2020 by 59 Comments

There’s a lot of good in the world and that includes you. Humanity has a way of coming together at crucial moments and we have certainly reached that with the outbreak and spread of the novel coronavirus. At this point, most people’s daily lives have been turned upside down. We can all have an impact on how this plays out.

It’s scary, it’s real, but we will get through this. What we need to focus on now is how we can behave that will lead to the best outcomes for the largest number of people. The real question is, how can we help? If you’re stuck at home it’s easy to feel powerless to help but that’s not true. Let’s cover a few examples, then open up the discussion in the comments so we can hear what has been working for you.

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The Corona Clock

March 19, 2020 by 19 Comments

Schools are closed here in Germany until after Easter vacation, and that means that our almost-six-year-old son Max is staying at home with us. The good news is that my wife and I work from home anyway, so it’s not too stressful as long as he can look after himself for eight hours per day. The bad news is that there’s no way a kindergarten kid can take care of himself for such long stretches, and we don’t want to just park him in front of the boob tube. At least there’s two of us.

The new stay-at-home life has required some adjustment, but for at least the first five days (and counting) it’s working out pretty darn well. One trick: my wife came up with the idea of a visual schedule to help Max divide his day up into kindergarten-sized chunks, and then we added an LED strip behind it to turn it into a linear clock of sorts. And we did it with stuff we had lying around the house.

Granted, it’s not a super deep hacky-hack, and some of you out there could probably get it done with a handful of 555 timers. But it was quick, gets the job done, and heck, with NTP sync, it’s the most accurate kiddie clock in the world! So those of you out there who are stuck like we are, trying to balance childcare and working from home, here’s a quick project that can increase familial harmony while giving you an excuse to order more LED strips.

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144 7-Segment Displays Combine To Form A Mighty Clock

March 5, 2020 by 25 Comments

What do you do with 144 7-segment displays? If you’re [Frugha] you put them all together to create an epic clock. Each display has 8 individual LEDs — 7 segments, and a decimal point. Put that all together, and you’ve got 1152 individual LEDs to control. This presented a problem, as [Frugha] wanted to control the clock with a single Arduino Nano. Even charlieplexing won’t get you that many I/O lines.

The solution was a nifty little chip called the MAX7219. The ‘7219 speaks SPI and can control 64 individual LEDs. [Frugha] used 18 of them in the clock, giving him full control over all his LEDs. That’s pretty impressive, considering the last matrix 7-segment display we saw required 48 Arduinos!

Another problem is memory – 1152 “pixels” would quickly overrun the 2KB RAM in the ATmega328. This is a clock though — which means only digits 0-9 and a colon. [Frugha] picked a nice font and hand-coded lookup tables for each digit. The lookup tables are stored in ROM, saving precious RAM on the Arduino.

A clock wouldn’t be any good if it wasn’t accurate. A Tiny RTC supplies battery-backed time data. [Frugha] wrapped everything up with a neat layout on a custom PCB. Sure, you could put it in a case, but we think a clock this crazy deserves to be left open – so you can see it in all its glory.