the 3 needle ammeters that make up the face of the clock

IC Clock Uses Ammeters For A Unique Time-Telling Display

It is a rite of passage for hackers to make a clock out of traditionally not-clock items. Whether it be blinking LEDs or servos to move the hands, we have all crafted our own ways of knowing when it currently is. [SIrawit] takes a new approach to this, by using ammeters to tell the time.

The clock is built using mostly CMOS ICs. A CD4060 generates the 1HZ clock signal, which is then passed to parallel counters to keep track of the hours, minutes, and seconds. [SIrawit] decided to keep the ammeters functioning as intended, rather than replacing the internals and just keeping the needle and face. To convert the digital signal to a varying current, he used a series of MOSFETs connected in parallel to the low side of the ammeters, with different sizes of current-limiting resistors. By sizing these resistors properly, precise movement of the needle could be achieved by turning on or off the MOSFETs. You can see the schematics and learn more about how this is achieved on the project’s GitHub page (at the time of writing, the most recent commits are in the ‘pcb’ branch).

In addition to the custom PCB that holds all the electronics, PCBs help make up the case as well. While the main body of the case is made out of a repurposed junction box, [SIrawit] had a PCB on an aluminum substrate manufactured for the front panel. While the board has no actual traces or electrical significance, this makes for a cheap and easy way to get a precisely cut piece of aluminum for your projects, with a sharp-looking white solder mask to boot.

We love to see cool and unique ways to tell the time, such as using Nixie Tubes to spell out the time in binary!

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Cool Binary Clock Uses Old-School LEDs And A Fancy Graphic PCB

Ah, the 5mm LED. Once a popular choice, they’ve been supplanted in modernity by smaller SMD components and/or more capable RGB parts in recent years. However, they’re still able to do the job and are a great way to give your project that proper homebrew look. [Ian Dunn] chose those very parts to produce his 4017 Decade Binary Clock.

The clock uses only digital logic ICs to tell the time – there are no microcontrollers here! After four or five iterations over almost a whole year, [Ian] was finally able to coax the circuit into reliable operation. As you’d expect, it relies on a 32.768 kHz crystal to provide a stable clock. Fed into a 4060 binary ripple counter, that clock is divided down 14 times to deliver a 2Hz square wave. This then goes through a 4027 flip flop to get the desired 1Hz signal. From there, a bunch of extra logic handles counting the seconds, minutes, and hours, and resetting the counters as appropriate.

The PCB that houses the project is printed on directly by a flatbed inkjet printer, which [Ian] purchased when inspired by our previous article on how to get your PCBs made at the mall. He didn’t actually use it to make the PCB in this case, but the flatbed printer does a great job of putting graphics on the board.

The result is quite an attractive look that might surprise a few electronics enthusiasts who haven’t seen a graphic printed board before. It’s a technique we think could be used to great effect on conference badges, too. If you’ve experimented with similar techniques, be sure to drop us a line!

Silicon Jumpers Make This Wire-Free Breadboard Programmable

There’s no doubting the utility of the trusty solderless breadboard, but you have to admit they’re less than perfect. They’re not ideal for certain types of circuits, of course, but that’s less of a problem than those jumper wires. The careless will end up with their components hopeless tangled in a rat’s nest of jumpers, while the fastidious will spend far more time making the jumpers neat and tidy than actually prototyping the circuit itself. What to do?

One way to crack this nut is to make the solderless breadboard jumperless, too. That’s the idea behind “breadWare” a work-in-progress undertaken by [Kevin Santo Cappuccio]. The idea is to adapt a standard breadboard so that connections between arbitrary pairs of common contact strips — plus the power rails — can be made in software. The trick behind this is a matrix of analog CMOS switch chips, specifically the MT8816AP. Each chip’s 128 crosspoint switches can handle up ± 12 volts, so there are plenty of circuits that can use these programmable silicon jumpers.

[Kevin] is currently on version 0.2, which is sized to fit under a solderless breadboard and make a compact package. He shared details on how he’s connecting to the breadboard contacts, and it looks like a painful process: pull out the contact, cut a small tab at the gutter-end, and bend it down so it forms a lead for a through-hole in the PCB. It seems like a lot of work, and there must be a better way; [Kevin] is clearly open to suggestions.

While we’ve seen crosspoint switching used to augment solderless breadboarding before, we find this project pleasing in its simplicity. The thought of tossing out all those jumpers is certainly tempting.

Inside An Oscillator With [Ken Shirriff]

We are always glad to see [Ken Shirriff] tear into something new and this month he’s looking inside a quartz oscillator module. Offhand, you’d think there’s not much to these. A slab of quartz and some sort of inverter, right? But as [Ken] mentions, “There’s more happening in the module than I expected…”

If you’ve ever wanted to decap devices, big hybrid modules like these are a good way to get started since you don’t need exotic chemicals to get at the insides. [Ken] managed to break the fragile crystal wafer on the way in. Inside was also a small CMOS IC die. Time to get out the microscope.

If you follow [Ken’s] blog, you know he’s no stranger to analyzing IC dice. The oscillator IC is a pretty standard Colpitts oscillator but it also provides a programmable divider and output drive.

The circuit uses some unusually configured capacitors. [Ken] takes the time to point out CMOS logic structures throughout. If you haven’t seen one of [Ken’s] deep dives before, before, it’s a great introduction.

You can learn more about crystal oscillator theory. We used some test equipment to characterize a crystal a few years ago.

Gorgeous Clock, And Not A Line Of Code In Sight

[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.

TRS-80 Clone Uses Modern Parts

Before RadioShack decided the best business model for an electronics store was to harass its customers into buying overpriced batteries and cellphones, it was a great one-stop shop for most discrete components, knobs, resistors, radio equipment, and even a popular computer. That computer, the TRS-80, is a popular one in the retrocomputing world and if you can’t get original parts to restore one, you can always build your own clone.

This build comes to us from [Glen] aka [glenk] who is known for retrocomputing builds like this classic PET we featured a little over a year ago, and this TRS-80 is his latest project. He really gets into the weeds on the hardware, too. This isn’t an FPGA or Raspberry Pi running a TRS-80 on lookalike hardware. [Glen] has completely redesigned the computer from the ground up using modern CMOS components in order to make a modern, perfectly functional replica of the RadioShack classic.

Because of the level of detail [Glen] goes into, this one is a must-read for anyone interested in computing hardware (as opposed to the software, which you could learn about through a more simple emulator) and retrocomputing in general, and also brings most of us back to a more nostalgic, simpler time where a trip to RadioShack was fun and interesting.

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Hackaday Links: September 22, 2019

Of all the stories we’d expect to hit our little corner of the world, we never thought that the seedy doings of a now-deceased accused pedophile billionaire would have impacted the intellectual home of the open-source software movement. But it did, and this week Richard Stallman resigned from the Computer Science and Artificial Intelligence Lab at MIT, as well as from the Free Software Foundation, which he founded and served as president. The resignations, which Stallman claims were “due to pressure on MIT and me over a series of misunderstandings and mischaracterizations”, followed the disclosure of a string of emails where he perhaps unwisely discussed what does and does not constitute sexual assault. The emails were written as a response to protests by MIT faculty and students outraged over the university’s long and deep relationship with Jeffrey Epstein, the late alleged pedophile-financier. This may be one of those stories where the less said, the better. If only Stallman had heeded that advice.

They may be the radio stations with the worst programming ever, but then again, the world’s atomic clock broadcasting stations can really keep a beat. One of the oldest of these stations, WWV, is turning 100 this year, and will be adding special messages to its usual fare of beeps and BCD-encoded time signals on a 100-Hz subcarrier. If you tune to WWV at 10 past the hour (or 50 minutes past the hour for WWVH, the time station located in Hawaii) you’ll hear a special announcement. There was also talk of an open house at the National Institute of Standards and Technology complete with a WWV birthday cake, but that has since been limited to 100 attendees who pre-registered.

For the machinists and wannabes out there, the Internet’s machine shop channels all pitched in this week on something called #tipblitz19, where everyone with a lathe or mill posted a short video of their favorite shop tip. There’s a ton of great tip out there now, with the likes of This Old Tony, Abom79, Stefan Gotteswinter, and even our own Quinn Dunki contributing timesaving – and finger saving – tips. Don’t stop there though – there’s a playlist with 77 videos at last count, many of them by smaller channels that should be getting more love. Check them out and then start making chips.

Most of us know that DLP chips, which lie behind the lens of the projectors that lull us to sleep in conference rooms with their white noise and warm exhaust, are a series of tiny mirrors that wiggle around to project images. But have you ever seen them work? Now you can: Huygens Optics has posted a fascinating video deep-dive into the workings of digital light processors. With a stroboscopic camera and a lot of fussy work, the video reveals the microscopic movements of these mirrors and how that syncs up with the rotation of a color filter wheel. It’s really fascinating stuff, and hats off to Huygens for pulling off the setup needed to capture this.

And speaking of tiny optics, get a load of these minuscule digital cameras, aptly described by tipster David Gustafik as “disturbingly small.” We know we shouldn’t be amazed by things like this anymore, but c’mon – they’re ridiculously tiny! According to the datasheet, the smaller one will occupy 1 mm² on a PCB; the larger stereo camera requires 2.2 mm². Dubbed NanEye, the diminutive cameras are aimed at the medical market – think endoscopy – and at wearables manufacturers. These would be a lot of fun to play with – just don’t drop one.