Plexitube Owl Clock

owlTickAnimationSmallFor Christmas I designed and built six steam-punk owl clocks that have a novel faux Nixie Tube display. Nixie tubes are wonderful with their glass tube bodies and brightly glowing numerals, but think how wonderful a solid-state low-power any color “Nixie Tube” would be!

The basic idea is that you position an LED at the edge of a piece of acrylic that has a pattern laser-etched into its surface, and the LED lights up the pattern. Long ago I’d realized that a stack of 10 laser-etched digits with an LED to light up each digit might have the same visual charm as a Nixie Tube, and the Plexitube was born.

I’m pleased with the way the project turned out.  I’ve put the software, circuit designs, and illustrator files up on github. I even made a short video of one of the clocks in action.  The project has even gotten some attention from Hackaday and won this Reddit unconventional clock competition.  Thanks a lot guys!


At the time it was unclear if light bleed between the layers would make the digits hard to read, so I sat on the Plexitube idea for a long time waiting for a project that could use that kind of display.

Then I went to work at a new company, and I had to spend an entire day listening to benefits summaries and corporate on-boarding. To pass the time, I started to do some sketches of an owl made from only two pieces of wood. I used my Swiss army knife to cut my co-workers’ name tags into owl prototypes. I really liked the design, and I thought it would be perfect for an owl-shaped clock with Plexitube eyes. Would this be this year’s Christmas Project?

I can’t really start a Christmas Project until after the Halloween Costume builds are done, but this project couldn’t really take shape until I’d at least tested the viability of the Plexitube. I figured if I just spent one evening laser-etching a digit stack and holding it over an LED, I could figure out if the displays were going to be an unreadable mess. If it failed, I could pull the plug on the owl idea before they got out of the paper prototype stage. So I spent one of my Wednesday nights making a prototype stack.

VeryFirstTestOfPlexitubeThe prototype stack had a lot of issues. The back digits where hard to read, there was a lot of inter-digit light bleed. I really couldn’t say for sure whether this was going to work. That’s pretty much the worst-case scenario for a make-or-break prototype. Really, I should have just stopped then, but I couldn’t stop thinking about the nice owl shapes.

The Impossible Project

Halloween came and went and I needed to decide. I even went so far as to do some prototypes of an alternative project that was much simpler, but I could tell that the owls were the ones that wanted to be made. I’m usually pretty careful planning one of these projects, and never before had I taken on one that had so many BIG unknowns. I’d never worked with surface mount electronics, never bent wood to such small radii, never designed a PCB with a lot of exact physical layout constraints, and never used an in-circuit programmer. I decided to go for it, but I knew I’d have to get first-time-success-lucky on a number of things, and I told my coworkers that I did not expect to succeed.

Two months and counting

realTimeClocksTime to make a lot of quick choices and order stuff from China. I chose the popular Neopixel surface mount LED as my light source. They could be any color and all 40 of them could be controlled using just one pin from my controller. I decided to go with the ATMEGA328p, which is the same chip in an Arduino UNO. I was building 6 clocks, so I’d need 240 LEDs. I ordered a reel of 500 from China, along with some surface mount capacitor and resistor assortments, photo resistors, and some DS3231 real-time clock modules with battery backup. Ordering things from China is very cheap, but it can take a few weeks for the stuff to show up, so I had to get that moving quickly.

Now ordering printed circuit boards from OSH Park takes something like 10 days, so I really needed to get that in the pipe. If the first set of boards were a complete blowout, I could still get a second order in, but I had to hurry.

lightGuidesCloseupThe LEDs I was using are much fatter than that 1/16″ acrylic layers I was using, so each layer needed to have a sort of integrated light guide leg that would stick out and sit directly above the 3 tiny color chips inside the LED. The alignment had to be exact. So I measured an 10-layer alternating stack of acrylic and black card stock to get the exact spacing, and then I had enough info to begin laying out the PCB.



OwlClockPCBTopI used Eagle CAD and finally had to spring for the non-free version so I could work with more than one page of circuit. I had to use some tricks with the Grid to get all the LEDs laid out in the exact right locations. After a full weekend of fighting with Eagle, I had something I could send off to OSH Park. I also quickly ripped one eye segment out into another file and ordered 3 small “test boards,” so I wouldn’t have to do my first attempt at reflowing a surface mount board with one of my giant and owl boards.

Then it was back to working in Illustrator on the design for the acrylic digit layers, black card stock separators, etc. I customized the digits of a font to make them slimmer. All the digits obstruct one another, so I wanted something that was lovely, but was mostly empty space so other digits could shine though. I also did some tricks like make the zero (which is in the back) a bit bigger/bolder so it would still read well though all the other digits.

Secret Symbols

Now on a clock there are 4 digits, but not every digit needs all 10 numerals. Heck, the tens of hours digit only really needs a 1. That leaves 9 layers for other special non-digit things. I could, in theory, have put some extra digits in the back of the tens of minute digit since it only goes 0-5, but I decided if I was going to be showing other info in those lower digits, it would be better to have all the digits there. I also decided to keep the 2 in the hour-tens digit so I could support 24-hour time in the future, and show a full year like 2016, etc.

I wanted to show the phases of the moon, sunrise and sunset times, moon rise and moon set times, etc. I used 6 of my 8 free digits doing the arcs of the moon. Because all the layers are at different depths, I staggered them so the arcs actually make a 3D sphere shape with the middle most arcs at the front. That left me with 2 layers. I used one for a sun outline that could be used along with the arcs to show things like the equinoxes/solstices.

The Magic Eye

That left me with only one free layer, which I used to add the outline of an eye. I realized that the arcs could be used to animate a slit-pupil eye looking back and forth. Of course I needed that! My owls eyes have eyes?! Yes … yes they do.

Plexitube Assembly

eyeElementBeingStackedEach eye element can display two digits, and they are laboriously assembled by stacking 20 digit layers and 20 paper masks on 4 brass pins in careful sequence. Thankfully, the digit layers were fairly easy to keep track of because they already had digits etched into them! Each acrylic layer has to have its protective plastic peeled away, and its etching scraped and dusted. Because the pins are press-fit, I had to carefully push them down on the pins without cracking the 1/16″ acrylic. The first stack took me 2 hours to assemble. My finger nails were frayed from all the plastic peeling and I had 11 more elements to make. What had I gotten myself into?!


First Reflow

solderPasteStencilingFinally the owl boards came! I had also ordered a solder stencil from OSH Stencils. When making a board like this, the basic process is a bit like silk screen printing. You position the PCB under a stencil and squeegee solder paste though the stencil holes onto the board. Then you place all the itty-bitty components onto the board with tweezers. Finally you oh-so-carefully put the board in an oven and heat it up until the solder paste melts and the parts all snuggle down exactly into place via surface tension. A while ago, I had built a special computer-controlled toaster oven in order to do just this process, but I had never used it!

intoTheToasterI kept waiting for my test boards to show up, but eventually I gave up and decided to do my first reflow on one of my giant and indispensable owl boards. I populated the board, put it in the oven, and pushed the button. Then I held my breath as the oven went though its 3-minute cycle. Success! The board came out looking perfect! It looked like something totally commercial, not something I’d made with tweezers and a toaster oven. MAGIC! Surface mount is awesome. I’m never going back!

fiveOfSixBoardsForOwlsOk, so the board looked like it was all soldered up, but would it work? I hooked the LED chain on the board up to an Arduino UNO (remember how those NeoPixels can be driven by just 1 LED?) and some quick code showed that all the LEDs were working! I blinked each one red-green-blue to test and they passed with flying colors! *phew*

owlClockDigitTest54Now for the real question: would the digit display actually look good or was the whole thing going be two months of work for an unreadable mess? I wrote some code to cycle though the numbers and positioned the eye module over the LEDs. It sort of worked, but it wasn’t great.There was quite a bit of cross lighting between digits, especially between digits 1 and 2.

I was extra sad I’d left that 2 in the hour tens digit. No one wants to look at a clock and not be able to tell if it’s 11:14 or 22:14. Something really needed to be changed. But what? I did, however, decide to get my second round of PCBs made. OSH Park sends out 3x boards, so if I wanted 6 by Christmas, I’d have to order the second round pronto.

OwlLogoI spent an evening designing a nice owl icon to put on the second round of boards, added two regulator bypass pins, and then sent the thing off. No time for anything fancy. It turns out the icon was a fail.  Even though I followed OSH Park’s guide lines it did not render properly.


Eerie Is Good

plexitubeCloseupOne thing I did notice while I was running that test is that although the digits were not yet crystal clear, the whole thing had a very eerie feel to it. It was almost as if I couldn’t quite tell what the heck kind of technology I was looking at. It sure didn’t look like LEDs. The layers of acrylic have a wonder full “hall of mirrors” effect on the lit segments.  I also noticed that the light bleeding off the tops/sides of the eye element were kind of hypnotic to watch go through their sequence. I had originally planned to cover the elements with a ridged copper cylinder segment, which would have looked steam punk, but not as strange/cool as that bleeding light. I decided to leave them uncovered.

Back To Body Work

Now that the boards and the eye element design were mostly settled, I had to get back to figuring out how to design the bent body of the owl. I did a second pass of designing the body in cardboard. I knew that trying to bend 1/8 plywood into a loop maybe 3 inches in diameter was going to be tricky and might be impossible. In a recent build, I’d used laser “kerf bending” to make it easier to bend curves in thicker plywood. Could I take that to an extreme? MicroKerf Bending™? I tried spacing the kerf cuts .1″ apart, cutting almost all the way though the plywood. The results where a satisfyingly bendy piece of wood. Still the owl has some very wide sections at the top of his eye arches and those were still quite stiff. Too much variation to be able to bend into a loop.It would have been nice to write some sort of script that would space the kerfs closer/wider based on the overall width of the piece, but I had to settle for just doing a few different spacings by hand.

owlBrowClampThe brows above the eye were delaminating when I’d apply the bend. That was bad. I fixed it by pre-sanding the upper layer thin in those areas and by putting a few little spring clamps on those edges during the bend. That solved the problem, but all these iterations on the body design were burning up time at a crazy rate. Would I make the Christmas deadline!? Here I’d been thinking I was saving time by having most of the owl form come from just one piece. So wrong.

Steaming and Clamping

owlInClampingJigI built a clamping jig out of a big board and carved away clearance for the owl feet. I’d steam an owl body in a pot on the stove and then bend it with my gloved hands whilst racing out to the garage to clamp the body around the face in my special jig. The first time I did this the face of the owl split in two! Yes, when the body is looped back on itself and clipped tail to feet the forces on the face are nice and balanced, but while you’re bending that around the forces on the face are actually pretty big. So I changed my clamping jig so it would support the face during the bend. Finally, it worked!

boardInOwlTestI had a lot of other little issues. I had to add some “foot prop” pieces so I could have a way of evening out feet after the main clamping was done. I thought I’d be able to adjust the owls stance by adjusting the tail angle, but a sort of scissoring action made it so any amount I pushed up the tail also pushed up the feet, canceling out the adjustment. So the owls look down a little bit more then I’d like. That’s okay though because they like to nest up high.

owlsOnTheClockFaceI wish I could have used 1/8″ mahogany plywood. Then I wouldn’t have had to deal with staining the outer body. However, that’s not something I can get locally so I was stuck with stain. I hate stain. I tired pre-staining, which gave nice crisp edges at the stain boundaries, but that made the gluing a lot weaker. I tried post staining with with pre-clear coating areas to try to reduce bleeding over, but it still bled some and required lots of awkward sanding to fix. If I had it to do again, I’d try to get hardwood ply. I did eventually get them all glued and stained.

The Secret Sauce

secritSauceUnderSideOfEyeI’d been thinking about my eye element problems. How could I improve the contrast? I already had black card stock all over the place blocking as much light as I could. I realized that as tight as the fit was around the card stock, there were still micro gaps, and the light leaks I was seeing were probably coming right up from the LEDs and into the clear bottoms of the other segments. I decided to use a small brush to paint some black acrylic into those areas! EUREKA! That fixed the problem entirely and now the displays looked great.

Christmas Eve

owlClockInFrontOfTreeIt was Christmas Eve, and I was still clear-coating owl bodies. Applying wood finish on Christmas Eve is par for the course for me. The big issue was that I was still driving the displays from a separate Arduino and hadn’t fired up the on-board computer at all. I spent a while reading about fuse bits and fighting with boot loaders, and fiddling with Arduino IDE config files. Had I made some mistake with as-yet-untested parts of the PCB? Could I get lucky one last time on this “impossible” project? Yes! At last, I was able to program the chip on the clock board, get the real time clock synced with Greenwich Mean Time, and put enough code in the clock that it could actually display the time! The clock could go under the tree.

Software in the New Year

Early on I had decided to punt on all but the most basic software until after Christmas. I had pages of ideas on fancy software features, and I knew I’d have enough trouble just getting the things physically built by Christmas. This was going to be a Christmas gift with an eventual “firmware upgrade” gift chaser.

owlSimulatorExplodedViewI knew there was going to be a lot of software, so I wrote a iPhone owl clock simulator to give me an easier platform to develop some of the code. I had been reading Jean Meesus’ Astronomical Algorithms, and I wanted to have the clock not only show the phases of the moon, but be able to display sunrise/set times and moon rise/set times.

I had included a light sensor on top of the clock so the clock could dim a bit when it was in the dark, but it could also tell if your hand waved over the clock and maybe then it would cycle though showing the sun going though sunrise colors while showing the sunrise time and the show the sunset time while cycle though the sunset colors.

Color Picking the Old Fashioned Way

colorPickerWithThreePotsAndUnoI really wanted to use nice colors in the clock, but just choosing 3 numbers for Red/Green/Blue doesn’t tell you what those are going to look like in the final display.  I needed a way to search for good colors.  So I made a super simple color picker by hot gluing three potentiometers to a board. I used an Arduino UNO to read the three RGB values and display the color on  a jury rigged LED + acrylic digit. Go Go gadget gaffer’s tape! The program would print the values out to the serial monitor.  That way I could find just the right pink by fiddling with the knobs and then write down that RGB triple from the screen.   I used that to make a whole pallet of colors I liked.

The Trouble With Doubles

The big problem was that most of the Astronomical Algorithms need double precision math. The solar system is big and you need the precision, but the Arduino tool chain doesn’t have real double precision math. I spent a while (stupidly) writing a math lib that did approximate double precision math using two single precision float values based on this paper targeted at GPU computation with floats. I did get the math working, but to my horror, I discovered that the code it produced to compute the equinoxes/solstices was so huge that it didn’t fit into the 32k of memory on the ATMeg328p. That was a huge waste of time. I did, however, use the code to generate the next 100 years of solstices and equinoxes and compress them down into just 100 bytes of Progmem, but the sunset/sunrise times were doomed. I went back to some still usable moon calculation code so the clock can show the current phase of the moon.

Then I wrote a lot of silly features. On the clock recipient’s birthday, it displays in their favorite colors. (And on their kids’ birthdays, their kid’s favorite color, etc)

I wrote all the code to set the time/date/gmt offset with nice auto repeat ramp ups and useful icons. (When you’re setting the month a sliver of moon shows, when you’re setting the day there’s a sun icon, etc) I even used the right arc of the circle to show AM and the left arc for PM like they were the first and second parts of a 24 hour clock face. Not that I expect people have to set the time/date much, but a clock needs to do that.

The clock counts down to midnight on New Year’s Eve and shows fireworks and a spinning golden globe at midnight. On JRR Tolkien’s birthday, the the eye of Sauron looks around and sometimes a golden ring spins and the digits are red and fade up and down like like a breathing beast.  etc.  I don’t want to give to many surprises away.

Needless to say, there are a year’s worth of Easter Eggs in the clock code, even on Easter.

Two Words “Optical Theremin”

photoresistorsWhen I was working on the auto-dimming feature, I wanted to have a direct readout of the light sensor, so I could fine tune a mass/spring system for the dimming rates. When I first hooked it up, I realized that with a much stiffer spring it was pretty neat to play with. You’d wave your hand over the clock and the digits would smoothly go up and down. It was kind of mesmerizing.

I was showing it to a friend, and when I started waving my hand around he said, “Wait, it has a Theremin too!?” and the Optical Theremin was born. I hooked that code up to the hue of an hsv conversion and now when you press the down button, you get one minute of “Optical Theremin” where waving your hands around changes the colors and numbers in a soothing and lovely display of Plexitube awesomeness.

It’s hard to stop writing code for the clock, but after the “Optical Theremin” feature, I started getting close to the memory limits and I decided to call it quits. It was time to give out festive springtime firmware upgrades! I had been trying super hard to have the code all done before the spring Daylight Savings Time change because people had clocks they couldn’t set! I only missed that deadline by a week. I blame double precision!


Clarence was starting to think that perhaps this hazing ritual was going a bit too far…


64 thoughts on “Plexitube Owl Clock

  1. Kurt,Thanks. This is both a very intriguing and aestetically pleasing project. Of course, I don’t comprehend the engeneering details. Your genius astounds me. Hope all is well with you, Cheryl and the lads. The latest so-called “plan” is that we hope to move mother back to Pavilion sometime next week. Of course, I’ll update you and Inge.Mike | Kurt posted: “For Christmas I designed and built six steam-punk owl clocks that have a novel faux Nixi Tube display. Nixi tubes are wonderful with their glass tube bodies and brightly glowing numerals, but think how wonderful a solid-state low-power any color “Nixi Tub” | |

  2. Thank you for posting such an inspirational article. I’ve often thought about trying to side-light some laser-etched acrylic, and even thought about layering 1-3 slices, but I hadn’t done it yet. Learning how to etch a PCB these days is still on the to-get-to list as well. Now I get to try carving/etching something plexi-tube-like.

    Neopixels are my friend, and a color-tuner really is the best way to find the color hue and intensity that you want, especially when you are trying to match one or more colors that will display together. Well done!

    • I do these projects for fun. The amount of work needed to turn a project like this into something customers could assemble would be huge. At least twice the scope of the project thus far, and there would still be significant work for me for every kit that went out. That isn’t something I’m willing to take on. I like the idea, and I guess it’s something I might consider for very simple projects that were easy to make from a sack of parts, but that’s pretty much exactly not what these owls are.

  3. I’m really impressed with how well the plexitubes worked out. I’ll have to reconsider my nixie plans… Also, I may steal some of your code. 🙂

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    • It’s up on GitHub if you look in Just be warned that file has everything in it and is undocumented/not very user friendly. Layers with “Cut Layer” in the name have .002 kerf offset already applied.

  6. Pingback: Plexitube Owl Clock – OSH Park

  7. Amazing work – creative, stretching your build skills, and attractive result. Would you be willing to share where/how you had the acrylic cut and etched?

    • Thanks! I’m glad you like it. I was happy with the way this project came out. I have access to an Epilog laser cutters via TechShop. So I did the cutting/etching myself. This project is pretty non-critical in terms of laser stuff so I’m sure having a 3rd party do the cutting/etching would be fine. I tuned the kerf compensation so all the brass pins could be a light press fit, but if they came back a bit loose it would actually be easier to assemble, and you could put a drip of cyanoacrylate on each pin to lock everything in place. The paper mask layers tend to keep the glue from wicking out so far as to cloud the important parts of the display.

  8. Kurt, I’m going to attempt to recreate your work and build an owl clock. I’ve ordered some boards from OSH Park, and have weeded through the AI file to figure out the cut layers for the digits, masks, and body parts. A couple of questionable points I have are: 1) the brass pins – what are the dimensional details of those, or where did you get them? and 2) the real time clock – there is some conflicting information between the circuit diagram and the board layout, but I’m assuming the RTC is a DS3231? If you have any other pointers, please share.

    • I just cut the brass pins from 1/8″ brass rod stock. Not sure about the exact length. “a little bit longer than the full stack of acrylic/card stock” Yes I used a DS3231. I was using one of those cheap $1 modules from China with the battery holder already in place, etc. I did remove the on board SMD LED so it wouldn’t be eating power/bleeding light into the interior of the owl. On the Owl PCB it’s just a pin header since I wasn’t using the DS3231 component on it’s own. Be sure to post some picks of your build! I didn’t do any refinement on the design to try and make this any easier DIY style project, so the build may be a bit of an adventure…

  9. Kurt, a couple of component questions: 1) the voltage regulator, I’d assume a 5.0V output voltage, 2.0% tolerance, and SOT-223-3 package, so the full IC part number should be MCP1703T-5002E/DB, and 2) what/where on the photoresistors? Hope you aren’t bothered by the questions.

  10. Hi Kurt,
    This is quite lovely. I found your site via someone who found my site while looking for advice on how to build an edge-lit display. Good on you for posting all of your files; I wish I were as well-disciplined as you and half the craftsman!

  11. What a great project! I’m going to be attempting to recreate this myself, based on your excellent documentation of your process. Pray tell though, do you have the body design files in SVG or another “standard” format for us peasants without Illustrator?

    • Oh I’m glad you like it! The design files are just what I used to make the clock, so they’re not super “organized” into something that’s easy to follow. So just be warned. Once I get to work I’ll see if I can convert the files into something else and email them to you.

  12. I have given up trying to find what I want on line so you my be able help me build a linear clock.
    What I have in mind is an LED fed Plexigalss display some 2ft long &
    6” high as slim as possible. The digits could be etched into plexi and illuminated from the base switching at the appropriate hour ( maybe blue for AM and red for PM.
    The minutes could also display as 60 individual numbers or as a moving bar.
    Sorry this is a bit vague. If you feel this is of interest I could send over further thoughts.
    Giles Smith UK

    • If you’re planning on building a clock like you describe I’d be happy to answer a few questions, or chime in with ideas. If you were thinking that you wanted me to build such a clock I’ve never done commissioned work. I barely have enough time to build some of the things I want to build, much less build things other folks want. Good luck with your build!

      • Thanks Kurt.
        I shall have go myself and maybe ask a few questions on the way.
        I was going to start by engraving some 10mm plexi. If I space the hour numbers an inch or so apart I am hoping the LEDs under each number will not spill too much to neighboring ones. I believe I can obtain a programmable controller to address the right sort of led strip. Haven’t thought about the minutes display yet.

        Gil s

      • Cool! If you have problems with edge to edge light bleed you could try something like black pin striping tape as an easy way of adding light masking. Good luck with the build! When you get a bit further along be sure to send me some pics!

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  14. I really liked the design of the owl clock. I have a question, is it possible to receive files of clockwork elements in a different format than Adobe Illustrator? Unfortunately, I do not know this program and I have a problem with matching individual layers to elements.

    • I’m sorry, all I have is the Illustrator file. Also admittedly that file is just the file I used to create the clock. I never cleaned it up or simplified/labeled it in any way that would help make this thing a “kit”. The clock is complicated to build so making a document that was anything like “build instructions” would be a crazy amount of work. So I never attempted to write such a thing. That would be an even bigger project than the initial clock design. I do think that a determined person could build one of these clocks using the included files, but it’s pretty non trivial. I’m no sure if I did that back then but one clue is to look for layers that start with an _ those are usually layers that have had kerf compensation applied and are ready to be laser cut, depending on the time period it they might also be labeled as “to cut”. Sorry I don’t have any help more detailed then that!

      • Thank you for your response . It is a pity because the project is noteworthy and deviates from the standard projects that can be found on the internet. Maybe if individual parts were saved in separate files, it would be easier to complete the whole project.

      • I have some questions regarding the construction of the clock:
        1. The order of editing the digits
        2. What are the spacers between digits made of?
        3. The numbers have different spacing, so be it?
        4. How did you bend the owl’s body, did you wet the plywood?
        5. Do you have more photos from the clock assembly?

      • The spacers I put between the layers were laser cut from black card stock. That gives the eyes even more of a Tube like look, and cuts down on inter-layer light bleed. I don’t know what you mean by the numbers having different spacing. Are you talking about the the light guides on the bottom of each digit those are staggered around to match the LEDs on the PCB. If you’re talking about there being more space between the first pair of digits and the second that’s intentional. Clocks often have a : between the pairs of digits and owl’s eyes force you to have the be separate. In the text of the blog I talk about how I bent the wood. First by micro kerf cutting using the laser and then by steaming the wood and clamping it in a jig that bend the curve. There’s a picture of that in the post.

  15. Thank you for your answer, but not everything is clear to me yet.
    1. Set up digits 0 at the base of type B and type D differ which is correct?
    2. A layer marked as Foot Support from which material is made and where it is placed.
    3. A layer marked as Board Standoffs from which material is made and where it is placed.
    You did not write in what order the digits are mounted, whether the order is 1 … 0 or different.
    Regarding the masks, the numbers are shown as single and double, which are correct?


    • If you look at the owl simulator image above it actually shows all the segments/digits and their orders. Most of the displays are ordered 1234567890 . (from front to back) . The hours digit is more complicated since it only has to show 1 and 2 digits, but the ordering of the moon wedges/sun/eye outline is important. You can see it in the simulator image. I think the boars standoffs are just 1/8″ acrylic and are used under the board where the screws go though.

    • The body of the owl is 1 pice that includes the wings/nose bridge/tail/feet. There are some other parts inside that form where the PCB mounts, etc.

    • Sorry I’m away on vacation. So I don’t have the code in front of me but much like a normal clock there is a set button and then up/down buttons. Cycling through the set should do something like Hours/Minutes/GMT offset/year month day? The month has a moon and the day shows a sun so that should help with the order. Did you actually build one? Send some pics!

    • Wow this is very exciting to see someone actually having build the clock! You’re the first to send me actual pictures! It does seem like you have the order incorrect in the symbols. I think this image shows the ordering the best The light pipe feet should also help determine the ordering because if that ordering it off they won’t align with the LEDs. In general the LEDs are very bright. It is however possible that if you’re photoresistor is not working properly the software is dimming down the LEDs since that’s what it’s for. I’ve had folks complain that the clock is too bright in full darkness. The photo-resistor helps adjust the LED brightness to better match ambient conditions, so it dims the entire display if the room is dark. I’m really impressed you’ve gotten as far as you have!

    • Also if you are having brightness problems you might want to double check how closely the light pipe feet align with the LEDs. I seem to remember that because of my lack-of-skill with Eagle CAD I was unable to make the screw holes that mount the digits to the board are not in the same exact relationship with the LEDs on the board for the two different sets of digits. So I actually have 2 different pieces of plastic one for the left stack and one for the right stack. I think they have dot’s on them to distinguish which is which. If you’re having alignment issues where the feet are not squarely on top of the LEDs it’s possible you need to swap which version of the piece of plastic the hole goes though. (or just file the hole a bit and nudge things around until the alignment is very good.) .

  16. I think there is some commented out code that will show the ADC output on the clock face and you can cover/uncover the resistor to see what range is appropriate. Photo resistors tend vary a lot in overall value so I tuned the range individually for each of the clocks. The clocks don’t react quickly to changes in light level. There is the optical Theramin mode to see fast responses to light levels.

    • There is a function that is called twelveHourValueFrom24HourTime. If you remove that from the places that are calling it and instead us the 24 hour time directly you should be able to get the clock to display 24 hour time fairly easily.

  17. Holy Cow! You did it! AMAZING. I never thought someone would preserver and build an entire owl. Nice work! 24 Hour time is not built into the default firmware. It would be pretty trivial to change the code to do that though. I just don’t know how comfortable you are with those kinds of changes.

    • I noticed that in your video those segments were all lit white or something. I thought maybe that was something you were doing intentionally. Do they not update at all?

  18. Hi Kurt! In this year full of lock-down(s0 I finally find the time to try to reproduce you beautiful project! In fact, I am wondering about some stuff:
    – I have no knowledge about PCB. Is your one, as you present it in OwlClock2.brd file, ready to be printed? What i do not understand is if I would need other electronic components a part from the board designed by you.
    – Do you have files a bit more clear on all the layout for laser printed number and shape? Time to separate layer using inkscape is -> infinite :’).

    • Hi Tommy. I’m humbled that you like the project enough to attempt it. I think only one other person has successfully built one of these clocks, and they only built the digits/electronics, not the owl itself. As you’ve already started to discover the design files/electronics are simply the files I created/used. Not something that’s been carefully trimmed down/documented as a detailed How To. I’m happy to answer questions, but it’s been 5 years since I built those so there are limits to how much I remember about the build. As for your question about the PCB, you can get the PCBs made using those .brd files, but they will not be populated with components. The .sch file contains the schematic and the components used. So you would have to buy the various components and reflow all the surface mount components onto the board, use an iron to solder on the through hole components, and then program the boards. If you’ve never done that you may want to look into what is involved. My loom video has a little montage that shows a board like that being populated to give you a basic idea. I always build projects that are just within the bounds of what I can manage to build. Making them easy for others to build is never on the radar, and would change a lot of the design decisions.

      • Looking into it more you can get places like PCBWay to make a board that’s already populated with the SMD components. You might still want to do the through hole components yourself to save cost and because that’s quite simple to do.

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