Andrew's Blog


Ever since I saw the “Death Calls the Tune” project by Lab Binaer (via Make and Hack a day)  have wanted to get in on the Phosphorescent screen coolness. As luck had it a broken record player showed up in the local pawn shop (someone had torn out the needle assembly, also damaging the USB/sound board). For the princely sum of £1 I was thus the new owner of a skytek tec-3100.

Note: I know the images show the text on the screen to be illegible, I cannot capture with my camera a decent photograph of the screen. Please take my word that it is much more readable in person than the images would seem to indicate.


It doesn’t work by witchcraft, in fact the principle is very simple. Glow in the dark paint (I’ll just call it glow paint) reacts to UV, effectively UV light will “charge” glow paint. When given a very brief flash of UV the paint persists in glowing for a few seconds but the brightness rapidly dwindles. By placing an array of UV LED’s above a moving sheet of glow in the dark material we can draw images and text. Since the paint is brittle the object it is painted on cannot be allowed to warp (or else the paint will eventually flake off), which means that we can either use a spinning disk or other spinning shape that is symmetric about a plane of rotation (like cylinders and cones). A disk is by far the easiest method of achieving the desired effect, and record players already spin disks at a slow steady rate – quietly and very reliably. I decided to use the felt “under mat” that came with the device as the canvas for the paint, largely because the thought of ruining a perfectly good record might upset someone.


Internally tec-3100 was impressive. Control for the stylus arm was all run from a central wheel which had groves that would actuate the movement of the reading arm with a series of control rods, a truly lovely piece of engineering (as you might be able to tell I love smart design like this). Despite the use of USB and micro controllers the stylus arm control was done by mechanical computer to presumably keep costs down. Unfortunately since all this was useless to me I stripped out all of the control rods leaving just the table rotating motor, the power supply and the front switch for speed selection. Happily the damaged USB/sound circuit board was only connected for power (~12v) to the separate “power board” and was removed without fuss.

Movement of the stylus arm is controlled by a tiny (and cheap) servo motor, unit price was roughly £5. Since I cleared out all the control rods and gears there were plenty of mount points for the servo. The connector between the servo horn and the record arm is actually a wooden skewer (with the point cut off). I found that this gave a certain amount of flex that would reduce the stress caused by fast movements of the servo (also it is a nice and cheap, replaceable point of failure in case the arm is subjected to undue stress).

The build went exceptionally smoothly; there are 4 small circuit boards that I had to make, largely because this modular approach allowed me to breadboard and test everything was working board by board. But also because the number and spacing of screw pegs inside the device, and the awkward crevices and nooks lent itself to this approach too. The boards are;

  • Power regulator for servo (12v to 5v)
  • Shift register and connector for LED’s
  • Main board containing an Attiny2313
  • USB board (cobbled together from the original USB connector from the audio board and a USB to Serial converter (Nokia USB connector))

I realised fairly early on that there would simply not be room in the flash of the attiny2313 to contain all the data necessary to render a 8 by 5 fixed width font (and currently I do not have any Atmega devices to hand.). So this data is piped over the serial connection. As a bonus this means font can be dynamically switched if necessary. As a bonus bonus the font does not have to be fixed width. As a bonus bonus bonus you can handle symbols and icons, the only constraint is that the height is limited to 8 pixels. All in all I would say the draw backs with this design are that;

  • The screen is always tethered to a PC (i.e. as-is it cannot operate as a stand alone device)
  • The serial channel constrains the output speed. Resultantly the code is a little messy (with many Thread.sleep(500) calls waiting for a response)

The general principle is that the device operates in one of three modes; output to stylus, move stylus and command mode. In command mode the device waits for a new mode to be given via serial. In Stylus write mode the device outputs every character given to it over serial (if it gets a zero then it clears the output and enters command mode). In Stylus move mode the stylus is moved to any position (0..255) and then returns to command mode. The Stylus movement is limited in software to stop the servo pushing too far and breaking something. Since the “mode” is echoed back over serial the computer can tell if something has gone wrong with the modes and endeavour to fix it. As a side note, more modes can be added if needed with minimal fuss, a provision that may be useful if switching to a more capable platform like an atmega series device.

The computer side “device manager” program reads a “font file” (an XML file with definitions for each character)  then connects to the screen and sends instructions to move and write. This device manager is itself connected to by a socket. This allows anyone on the local network to put messages on the screen via the socket. Currently the only functionality is to write text to the screen, and the screen manager moves the cursor and handles font conversions. The current implementation is a proof of concept, I expect to make continuing modifications (see Future section) to bring it up to a release standard.


I’m fairly happy with the result. I would have been happier with access to SMD UV LEDs (alphabet soup!) but the 5 mil LEDs have worked fairly well. I have now realised that the “Death Calls The Tune” project have a very slow rotation on the platform. Currently my implementation is readable but it could be better, and it is certainly not as readable as the project that inspired it. I have no idea how to slow the motor down further, I have hacked the motor to run much slower than it’s default speeds, however it is still marginally too fast. I suspect that limiting the voltage available to it may do the trick. The motor is not a standard stepper/DC motor it appears to have an internal speed controller designed specifically for record players (lowering the voltage may cause it to fail and the motor to stop entirely). I may have to replace the motor, which is a shame but not undo-able.

With all this said the first time the display printed “hello world” I was on top of the world, and I am very happy with the project. Currently I am working on bringing the computer side interface up to scratch, but aesthetically the project is pretty much there, apart from exceptions noted in the “Future” section. The clarity of phrases is limited and the most legible “ring” is the middle ring, the inner ring text is a little warped by being so close to the point of rotation. Conversely, outer ring text is barely distorted at all, but the speed that the table rotates at means you need to be a fast reader. The latter could be mitigated by reducing the table rotation speed, the former by reducing the LED size. The trick to reading the outer ring appears to be to let your eye’s natural reading “skip” reflex to take over and track the words…this is somewhat disconcerting at first and it is easy to fall behind and miss words.


I plan to make some further hardware and software updates;

  • SMD LEDs instead of the 5mil LEDs currently used, possibly using more than 8 on the write head to allow a greater clarity and number of fonts (16 SMD LED’s could fit in the space of 8 5mil LEDs)
  • More functionality, like text output that spirals in or out of the disk, a graphic bar chart style output, a seismograph style output, etc.
  • Attiny bootloader (including breaking out the rst line from the USB to Serial) or
  • Move to atmega series and store character rendering data in flash.
  • Release code and plans for others to work with (preferably polishing the project a little more before this stage)
  • Move to a direct network connection, negating the need for USB and a supporting computer. (Serial connection maintained for extensibility purposes). Probably by means of a wiznet chip/board.


If anybody wants to do something similar I would be more than happy to help, swap notes and so on. I’m happy to share the code with individuals, however until the project reaches v1.0 stage I can’t say it would be reliable or indeed very good, so I wont release publicly until I am happy with stability and extensibility. The source and any designs still need some tidying. In short the project needs a little more work before I sign my name to the designs, so to speak. Please check back to my blog for updates, source releases and new info.


7 responses to “Spindleumen

  1. Benjamin Mayer December 28, 2010 at 7:59 am

    Dear Andrew,

    my name is Benjamin and i am one part of lab binaer. On the one hand it is a great honor for us to see that a fan of our project »Death Calls The Tune« tries to build his own light-printing record-player.

    On the other hand we are a group of artists who make our living by having great ideas developing them and selling them to or clients. We ask you to respect our copyright and not to clone and to publish our project in such a direct way!

    I hope you can understand our situation,

    • thouton December 28, 2010 at 5:26 pm

      Hi Benjamin,
      Firstly, thanks for voicing your concerns publicly, I appreciate open discussion and honest discourse. Secondly, I can fully appreciate your concerns – I can see that as an arts group you need to fund yourselves and future works (…I really don’t want to harm your organization in any way).

      My first counterpoint (possibly the most contentious) is I do not see where the issue of copyright enters into the discussion; The “Death calls the tune” project is a combination of software and hardware. My implementation is undeniably based upon your idea, however, all circuit designs, software and firmware has been created by me as well as photographs and blog content. I acknowledge of course that my project is currently very close to yours in appearance and behavior – however I do not think that the label “clone” is appropriate, it is my intention to produce a wider range of visual modes and functionality than your original design includes. I fully acknowledge that your idea of using a record player is innovative, but this would not fall under copyright as I am aware of it. I would also point out that you yourselves have reused an innovative idea, insofar as “Death Calls the Tune” is based upon previously showcased technology with regard to using glow paint to hold a persistent image, such as the “Ghost matrix” project.

      My second counter point is that I have no intention of harming your organization or your profits and I am willing to enter into a discussion on how to minimize the effect of continuing my project. My motivations are of the vein of innovation, recycling and hacking. It was not my intention to sell any of my work (further more I intend to release my software and designs open source).

      My third counter point is that it is very unlikely that you will suffer a drop in custom because of my actions. Your idea is not hard to emulate from the perspective of a competitor (this may sound provocative, but please read on). I am not an electrical or mechanical engineer (I am a software developer) and yet I was able to complete the hardware side of things over a weekend (since I programmed the software myself the software side of things is irrelevant). If a competitor or customer was interested in making a clone they would not have to expend much effort in doing so…That this hasn’t happened suggests that your brand (Lab Binaer) is much stronger than you give credit for. More generally my target audience and your target market are entirely disparate, as far as I can see (mine being individual hackers, yours being installations and organizations). To argue that someone may use my work to encroach on your market is disingenuous, in that they could equally use your videos and documentation on the subject to replicate your project too (similar levels of technical competency would be required in either case).

      Finally I suggest that this could actually constitute an additional revenue stream for you. My intention is to release (open source) all designs and plans, but with your brand strength I think that you could release kits (pre-flashed chips, unpopulated PCB and other components bundled with instructions) and be reasonably sure (given the popularity of your projects) that you would be able to find a market. This business model (open source, open design) has been used by Lady Ada and others to great success.


      P.S. I’ll not make any software or design release until we have discussed the issue further (pending your timely response), although I may make blog posts on my progress in implementing software and hardware.

    • thouton January 4, 2011 at 11:35 pm

      Hi Benjamin,

      It has been a week since you posted your initial message and you have not responded to my or others points neither on my blog nor on the Instructables forum, therefore I will assume that your none responsiveness represents agreement with the arguments I put forth in my response. As a result I will begin releasing programs, source code and designs in my own time.

      If you decide that you do intend to discuss the issue with me further, please just leave a comment on the same posts as your original messages.

      As stated previously, one example of a way that this could help Lab Binaer is that I could pre-release the circuit designs to Lab Binaer (not that they are particularly complex), you could use those designs to put together a kit. The profitability of this strategy is contingent on there being a market for people making their own versions of this device (an assumption you seem to have made in your original post).


  2. Benjamin Mayer January 18, 2011 at 6:43 pm

    Dear Drew,

    i am (we are) pretty busy right now. But i will respond to your points soon…


  3. Benjamin Mayer February 23, 2011 at 7:55 am

    Dear Drew, i am not a native speaker in English so maybe Copyright is not the right word for what i ment in my first statement?!

    Anyway. Even though our project »Death Calls The Tune« is based on existing hard- and software the fact that makes an artwork out of it is the conception and the unique combination of everything! Also your point that it is easy to rebuild is no reason or allowance to do that… I think we both know a lot of innovative stuff which would be easy to copy but even so we would/should not do it .-) We also know about the possibilities of »Open Source« but we want to decide on our own when to publish one of our projects under this conditions!

    But what is more important to me than discussing about every point is to tell you that we do not want to start an juristic discussion with you or furthermore hire a lawyer to explain our point of view – we are friendly peaceful people .-). We just want to ask you, not to copy (“currently very close to yours in appearance and behavior”) our idea and publish the results or the construction plans via the internet.

    But once more we are very proud that you are fan of our project! Maybe you should have contacted us before you started your work and we could have started some kind of cooperation…

    Maybe even this time i did not find the right words… But i am sure you know about »Creative Commons« (! We are discussing right know to publish our next projects under one of that licenses to show more clearly what i tried to explain to you.


    • thouton February 23, 2011 at 12:04 pm

      Hi Benjamin,
      First of all, thanks for the reply (though it took a while!) I have been waiting to update this project properly for a while. Your English is excellent and I think that I can see where you are coming from by using the phrase “copyright” – I do however think that the concept is not relevant here and the misunderstanding stems from a misinterpretation of the idea of copyright.

      I agree with you when you say;
      ” the fact that makes an artwork out of it is the conception and the unique combination of everything “
      My point is that my project is not the same as yours (not just a clone, and therefore the “unique combination” of my project differs from yours). Just like your project is clearly related to the projects that went before, such as the ghost matrix, mine is clearly related to your project – but it does also differ significantly. I am working in a fundamentally different direction, my project is designed for ease of use, ease of application to new hardware and ease of configuration. To reiterate, my project has different goals from yours, mine are functional, yours are (I assume) artistic and aesthetic. Furthermore in terms of design my implementation clearly differs from yours, your project having used (as I understand it) and Arduino, native servo hardware in the record player, Surface mount LED’s in the stylus, and so on. In short – how your project is constructed and used is different from mine.

      Examples of how my project differs from yours;
      – Spindleumen itself is highly XML settings oriented, so that it may be re-configured for alternate hardware.
      – Spindleumen is designed to be adapted to existing record player hardware of different sizes and specifications.
      – Spindleumen is focused on displaying generic information, not specific feeds such as the carefully selected content that you showcase in your project video.
      – Spindleumen is designed to be controlled via a local computer and messages over a network.
      – Spindleumen is not an art project (Unlike ‘Death Calls The Tune’), it is unlikely to find it’s way into a gallery – largely because whomsoever did that would clearly be imitating you and not expressing themselves or any idea. It would not qualify as art, as I understand it.

      – The use of a record player for a use other than playing records (as a display)
      – The underlying technology; the UV glow screen (however this is not your innovation as it has been done before)

      I also agree when you say;

      … your point that it is easy to rebuild is no reason or allowance to do that… I think we both know a lot of innovative stuff which would be easy to copy but even so we would/should not do it .-)

      Allow me to clarify – as previously stated I do not intend to make money from this project, nor take your clients by copying you. Further more I only took inspiration from the reuse aspect of your project, I do not claim the same artistic or aesthetic motivations. My point is that you appear to be safe from someone trying to take your clients because no one has tried to (including me!), despite the ease with which they could. Further more in intellectual property it most certainly does matter how different and complex a project is – in patents for example.

      I have done many things differently from your project; The current update page for my project is /here/ I think that it relatively clearly shows where I wish to take my project (and that motivation and target audience is different from yours). If you still feel that I am copying;
      “We just want to ask you, not to copy (“currently very close to yours in appearance and behavior”) our idea and publish the results or the construction plans via the internet. “
      I would appreciate a concise description of the exact aspects that you feel should change before I could release my project. I also ask you consider the moral implications of preventing me releasing my work – in that I have produce original work (software) that uses hardware superficially similar to yours (although mechanically different) which I may not release despite being fully entitled to.

      Consider this situation reversed; what if Fisher (the manufacturer of your turntable) contacted you and refused to allow you to publish, distribute, document, share, use or sell your project because your project resembled their record player? Their “original idea” is the design of the record player, it’s appearance and mechanics – your project only modifies these with a slight visual change (modified stylus is the only visual aspect altered as the record disk is not part of the player) and the rest of the innovation is software. Would you feel that it would be within the rights of Fisher to do this? If the answer is “yes” then presumably you would have explicit authorization for this project from all parties that may lay claim to heritage of visual aspects of your project;
      – Fisher – the manufacturer of your turn table
      – J.J. Thomson (or relevant representative) – the inventor of the original phosphorescent display technology
      – rrmutt – creator of the ghost matrix project
      – and so on for inventors of revolving displays, servos, Atmel, Arduino, LED’s etc.

      Finally, I would prefer that we did address every point that we each make. I agree that a lawyer would be far from desirable, and somewhat irrelevant – I have been talking based on reasoning, not on jurisdictional law. I see your objection on moral grounds (which it seems to be) and I am willing to discuss (as already shown) the issue in those terms. As I have already shown I am very much willing to negotiate and reason with you, in what I hope you perceive as a friendly attitude. Given advice from others online I am confident that by releasing all my designs and plans online falls within fair use clauses of copyright law, this however has not been my concern (my concern is your opposition to such a move).


      p.s. I understand the concept of the creative commons licenses, however I do not understand why you reference it. For example the visual appearance of your Fisher turn table has most certainly not been released under creative commons, and yet you use it’s image on your website, youtube and sell to your clients.

      • Dr Iguana June 27, 2011 at 2:47 am

        Hi Andrew,

        Nice project. You mention that the text is a bit hard to read. I wonder if the whole project could eventually be mounted on a platter and spun behind a stationary glass sheet coated with fluorescent paint. Then you’d end up with a ‘radar’ like display that would be more legible and also quite cool. A departure from your current design but an interesting idea. Kind of a POV display with chemical assist. Without the fluorescent paint you need to spin these displays at a pretty brisk pace, about 15Hz I think. At 1Hz or less a stepper would suffice.

        I’ve been reading the conversation between you and Benjamin and it’s easy to see both of you have valid concerns. Benjamin seems concerned about losing business but honestly he probably ought not to worry.

        First, as you pointed out, the audiences each of you address are radically different. People who build things won’t buy something like this and visa versa. For builders like you and I, it’s the process that matters and not so much the result. Also, although a little sadly, the number of people who follow these DIY projects are quite small. On my own site the audience numbers less than 100. Ironically when someone makes a fuss about DIY projects it sometimes drags them into the limelight, quite the undesired result.

        Secondly, if I have some oil paints and a canvas is it OK for me to paint some sun flowers? Certainly it’s been done before and really quite well. But that alone wouldn’t act as a reason not to paint those flowers again although, of course, not identically. Similar is OK. Nobody would then mistake them for THE sun flowers.

        And finally, in my opinion companies excel through innovation. Competitors will of necessity lag behind if you set a blistering pace. Energy spent trying to suppress competition would be better spent coming up with new ideas.

        Thanks for the cool project and hope that you and Bejamin can reach an agreement.

        Dr. Iguana

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