As [tonyp7] freely admits, this is a pet project that’s just for the fun of it, made possible by the flood of surplus parts on the market these days. The VFD tubes are IV-25s, Russian tubes that can be had by the fistful for a song from the usual sources. The seven small elements in the tube were intended to make bar graph displays like VU meters, but [tonyp7] ganged up twelve side by side to make 84-pixel displays. The custom driver board for each matrix needs three of the old SN75518 driver chips, in 40-pin DIPs no less. A 3D-printed bracket holds the tubes and the board for each module; it looks like a clock is the goal, with six modules ganged together. But the marquee display shown below is great too, and we look forward to seeing the finished project.
Word clocks, or a matrix of light-up letters that spell out the time, are a standard build for all enterprising electronics enthusiasts. The trouble is finding the right way to drive a matrix of LEDs and the significant amount of brainpower that goes into creating a matrix of letters that will spell out the time without making it look like it’s supposed to spell out the time.
For his Hackaday Prize entry this year, [Stephen Legge] is creating a standard toolkit that makes word clocks easier to build. It’s a hardware and software project, allowing for LED matrices of any reasonable size, and the software to make a grid of letters that only spells out the words you want and not the four-letter ones you don’t.
The hardware for this project is built around the IS31FL3733 LED driver from ISSI. This is an interesting chip that takes I2C in and spits out a LED matrix with very few additional support components. This chip provides [Stephen] with a 12×16 single-color LED matrix, which is more than enough for a word clock.
Where this build gets slightly more interesting is the creation of a custom matrix of letters that will still spell out ‘quarter to noon’ when lit in the appropriate way. This is a big challenge in creating a customized word clock; you could always borrow the layout of the letters from another word clock, but if you want customized phrases, you’ll either have to sit down with a pencil and graph paper, or write some software to do it automatically.
It’s a great project, and since all of [Stephen]’s work is being released under Open Source licenses, it’s a great entry to the first portion of the Hackaday Prize where we’re challenging hardware creators to build Open Hardware.
Looking for an eye-catching and unique way to display the time and date? Want the flexibility to add other critical information, like the number of YouTube subs you’ve got? Care to be able to read it from half a block away, at least at night? Then this scrolling glow-in-the-dark dot-matrix display could be right up your alley.
Building on his previous Morse code transcriber using a similar display, [Jan Derogee] took the concept and went big. The idea is to cover a PVC pipe with phosphorescent tape and rotate it past a row of 100 UV LEDs. The LEDs are turned on as the glow-in-the-dark surface passes over them, charging up a row of spots. The display is built up to two rows of 16 characters by the time it rotates into view, and the effect seems to last for quite a while. An ESP8266 takes care of driving the display and fetching NTP time and YouTube stats.
We’ve seen “persistence of phosphorescence” clocks before, but not as good looking and legible as this one. We like the approach, and we can’t help but think of other uses for glow-in-the-dark displays.
If you wanted to make a rotating display box, what would you use to make it spin? A servo? A stepper motor? [ChrisN219] didn’t need his to move quickly by any means, and this opened up his options to something we probably wouldn’t have thought to use: a clock movement. Specifically, the hour minute part of the shaft.
Rotating lithophanes of your loved ones makes for a pretty cool project, and there isn’t a whole lot to this build to make it difficult. Much of it is 3D printed, including the tube in the center that the LED strip is wrapped around. The base is just big enough to hold the clock movement and the LED strip controller, so it would fit nicely on a desk or a mantel.
This is version two of [Chris]’ lithophane box, which gave him a chance to perfect the frame and design a thicker center post to withstand the heat from the LED strip. All the files are available if you want to print your own panels and take them for a spin. Since it’s so easy to change them out, you may end up with a big pile to choose from.
Clocks are a recurring feature among the projects we feature here on Hackaday, with several common themes emerging among them. We see traditional clocks with hands, digital clocks with all forms of display including the ubiquitous Nixie tube, and plenty of LED ring clocks. [Matt Evans]’s build is one of the final category, a particularly nice LED ring clock using wire-ended multi-colour LEDs. Other clocks produce an effect that looks good from across the room, but this one is also a work of beauty when examined in close-up.
Behind it all are four interlocking semicircular PCBs, an STM32F051C6T6 ARM Cortex M0 microcontroller which controls the clock, and a brace of driver chips. The different “hands” of the clock are expressed as different LED colours, and there is a variety of different colour and clock “hand” effects. An acrylic ring completes the effect, by covering the LEDs themselves. He’s put together a video of the clock in action, which you can see below the break.
Earlier in March we heard about a quirk of the interconnected continental European electricity grid which caused clocks to lose about six minutes so far this year. This was due to a slight dip in the mains frequency. That dip didn’t put anything out of commission, but clocks that are designed to accumulate the total zero-crossings of the power grid frequency of 50 Hz don’t keep accurate time when that frequency is, say 49.985 Hz for an extended period of time.
An interesting set of conversations popped up from that topic. There were several claims that modern alarm clocks, and most devices connected to mains, no longer get their clock timing from mains frequency. I’ve looked into this a bit which I’ll go into below. But what we really want to know is: are your alarm clocks and other devices keeping time with the grid or with something else?
Sometimes silence is the best compliment to a DIY project, and that doesn’t just apply to homemade lockjaw toffee. When a watch is so well-made that it looks like one from a jewelry store, it is easy to keep quiet. [ColinMerkel] took many pictures of his fourth wristwatch attempt but “attempt” is his word because we call this a success. This time around he didn’t forget the crown for adjusting the time so all the pieces were in place.
His second “attempt” at wristwatch making was featured here and it had a classical elegance. Here, the proverbial game has been stepped up. Instead of using stock steel, the body is constructed of 303 stainless steel. The watch dial will definitely draw compliments if its DIY nature is revealed, which is equally mathematical and charming. Pictures of this process were enough to convey the build without words which is always a bonus if you only want a quick look or English isn’t your first choice for language.