clock

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An RGB LED clock that resembles a color blindness test.

RGB LED HexaClock Doesn’t Actually Light Up The Night

April 27, 2024 by 5 Comments

Who says a clock can’t be both useful and beautiful? That seems to be the big idea behind the lovely little HexaClock from [Bulduper]. And boy, is it both.

Probably the most important part of this well-illuminated clock is the light sensor, which allows it to adjust the brightness automatically. If you’re not into that, well, there’s a really nice web app that’ll let you program the dickens out of it.

The brains of this thing is an ESP8266 on a custom PCB which controls the 127 individually addressable RGB LEDs. The clock may look large, but the big printed parts just fit on the bed of a Prusa i3. [Bulduper] used ABS because the LED strip and the PCB might get a little warm; they didn’t want to risk using PLA and having it turn into a Salvador Dali clock (although that could be cool).

Speaking of heat, make sure to use 18 AWG or thicker wires as [Bulduper] advises. LEDs may be efficient, but this clock uses lots of them! If you want to build one of these to bathe your wall in useful light, everything you need is available on GitHub. Watch HexaClock do its thing in the brief demo and walk-through video after the break.

If this is a little too bright for your tastes, check out this synesthesia clock.

Continue reading “RGB LED HexaClock Doesn’t Actually Light Up The Night” →

Synesthetic Clock Doesn’t Require Synesthesia

April 10, 2024 by 14 Comments

We often think of synesthetes as those people who associate say, colors with numbers. But the phenomenon can occur with any of the senses. Simply put, when one sense is activated, synesthesia causes one to experience an unrelated, activated sense. Sounds trippy, no?

Thankfully, [Markus Opitz]’s synesthetic clock doesn’t require one to have synesthesia. It’s actually quite easy to read, we think. Can you tell what time it is in the image above? The only real requirement seems to be knowing the AM color from the PM color. The minute display cycles through blue, green, yellow, and red as the hour progresses.

Behind that pair of GC9a01 round displays lies an ESP32 and a real-time clock module. [Markus] couldn’t find a fillArc function, so instead he is drawing triangles whose ends lie outside the visible area. To calculate the size of the triangle, [Markus] is using the angle function tangent, so each minute has an angle of 6°.

[Markus] created a simple but attractive oak housing for the clock, but suggests anything from cardboard and plastic to a book. What’s the most interesting thing you’ve ever used for an enclosure? Let us know in the comments.

Do you appreciate a good analog clock when you see one? Here’s a clock that uses analog meters for its display.

Video Killed The Radio Alarm Clock

March 29, 2024 by 4 Comments

For decades now, MTV has been on a bizarre trajectory given its original name was an acronym for Music Television. In the original days in the 80s and 90s it kept mostly true to its name, but starting around two decades ago they expanded into reality and other non-musical television programming and have now left it largely behind. Plenty of those who grew up in its heyday have an understandable amount of nostalgia for the channel as a cultural touchstone, and [Derf] used MTV archival footage to build a video alarm clock which helps him keep in tune with the past.

To keep the appropriate 80s aesthetic, the build uses a portable TV from the late 80s with its original CRT. The video files are hosted on more modern technology though, in this case a Raspberry Pi. The Pi is set up to run a python script which launches the VLC media player with a playlist loaded with video files, in this case a long list of MTV shows. Some configuration needs to be done to get it to output to the old CRT properly which depends on the hardware used, but once that’s in place it’s ready to be used as an alarm. [Derf] is using a smart outlet to power the TV at the appropriate time, and a cron job which starts the video player simultaneously at a somewhat random point in the playlist.

As far as retro TVs go, having one as an alarm clock is certainly a novel idea. We have seen a few others in the past, though, one to play the golden age of The Simpsons, and another that recreates the nostalgia of 90s cable television complete with a preview channel and era-appropriate commercials.

Continue reading “Video Killed The Radio Alarm Clock” →

Saving A Clock Radio With An LM8562

March 28, 2024 by 10 Comments

Smart phones have taken the place of a lot of different devices especially as they get more and more powerful. GPS, music and video player, email, and of course a phone are all functions tied up in these general-purpose devices. Another casualty of the smart phone revolution is the humble bedside alarm clock as its radio, alarm, and timekeeping functionalities are also provided by modern devices. [zst123] has a sentimental attachment to the one he used in the 00s, though, and set about restoring it to its former glory.

Most of the issue with the clock involved drift with the timekeeping circuitry. Since it wasn’t accurately keeping the time anymore, losing around 10 minutes a day, the goal to save it was to use NTP to get the current time and a microcontroller to make the correction automatically. Rather than replace everything in the clock except the display, [zst123] is using the existing circuit board and adding an ESP8266 to grab the time from the Internet. A custom driver board reads the current time displayed on the clock directly from the display itself and then the ESP8266 can adjust it by using the existing buttons through a relay wired in parallel.

Using the existing circuitry was certainly a challenge especially since the display was multiplexed, but the LM8562 that came with these clock radios is a common and well-documented chip for driving displays like this, giving [zst123] a leg up over something unlabeled or proprietary. Using NTP is certainly a reliable and straightforward way of getting the current time too but there are a few other options for projects like these like using GPS or even a radio signal.

Simple NTP Clock Uses Custom RGB 7-Segment Displays

March 17, 2024 by 15 Comments

A great majority of hackers build a clock at some point. It’s a great way to get familiar with electronics and (often) microcontrollers, and you get to express some creativity along the way. Plus, you get something useful when you’re done! [Tadas Ustinavičius] recently trod this well-worn path and built a neat little NTP clock of their own.

The build uses an ESP 12F as the core of the operation. It’s charged with querying an NTP time server via its WiFi connection in order to maintain accurate timekeeping around the clock. For display, it drives a series of custom 7-segment displays that [Tadas] built using 3D-printed housings. They use WS2812B addressable LEDs and thus can display a rainbow of colors.

For initial configuration, the phone creates its own WiFi hotspot with a web interface for changing settings. Once configured, it connects to the Internet over WiFi to query an NTP server at regular intervals.

It’s a simple build that does a simple job well. Projects like these can be very valuable, as they teach you all kinds of useful skills. If you’ve been working on your own clock design, don’t hesitate to let us know. You can use a microcontroller, relays, or even a ball.

The Perils Of Return Path Gaps

March 15, 2024 by 9 Comments

The radio frequency world is full of mysteries, some of which seem to take a lifetime to master. And even then, it seems like there’s always something more to learn, and some new subtlety that can turn a good design on paper into a nightmare of unwanted interference and unexpected consequences in the real world.

As [Ken Wyatt] aptly demonstrates in the video below, where you put gaps in return paths on a PCB is one way to really screw things up. His demo system is simple: a pair of insulated wires running from the center pins on BNC jacks and running along the surface of a piece of copper-clad board to simulate a PCB trace. The end of each wire is connected to the board’s ground plane through a 50 ohm resistor, with one wire running over a narrow slot cut into the board. A harmonics-rich signal is fed into each trace while an H-field EMC probe connected to a spectrum analyzer is run along the length of the trace.

With the trace running over the solid ground plane, the harmonics are plentiful, as expected, but they fall off very quickly away from the trace. But over on the trace with the gapped return trace it’s a far different story. The harmonics are still there, but they’re about 5 dBmV higher in the vicinity of the gap. [Ken] also uses the probe to show just how far from the signal trace the return path extends to get around the gap. And even worse, the gap makes it so that harmonics are detectable on the unpowered trace. He also uses a current probe to show how common-mode current will radiate from a long conductor attached to the backplane, and that it’s about 20 dB higher with the gapped trace.

Hats off to [Ken] for this simple explanation and vivid reminder to watch return paths on clock traces and other high-frequency signals. Need an EMC probe to check your work? A bit of rigid coax and an SDR are all you need.  Continue reading “The Perils Of Return Path Gaps” →

Educational Arduino Clock Uses Analog Meters For Display

March 1, 2024 by 13 Comments

When it comes to educational electronic projects, it’s hard to go past building a clock. You learn tons about everything from circuit concepts and assembly skills to insights about the very nature of time itself. And you get a clock at the end of it! [hamblin.joe] wanted to do a simple project for kids along these lines, so whipped up a neat design using analog meters to display the time.

The build relies on that old stalwart, the Arduino Uno, to run the show. It’s hooked up to a DS3231 real-time clock module so it can keep accurate time for long periods, as is befitting a clock. Displaying the time is done via the use of two analog meters, each fitted with a custom backing card. One displays hours, the other, minutes. The analog meters are simply driven by the PWM outputs of the Arduino.

It’s not a hugely complex project, but it teaches so much. It provides an opportunity to educate the builders about real-time clocks, microcontroller programming, and even the concepts behind pulse width modulation. To say nothing of the physical skills, like learning to solder or how to assemble the laser-cut enclosure. Ultimately, it looks like a really great way for [hamblin.joe] and his students to dive into the world of modern electronics.