The latest blog posts.

  • Finally, at long last, I got my two 52-tooth gears for my Orrery!

    Finally, at long last, I got my two 52-tooth gears for my Orrery!

    It took another couple of tries, and the trick for these gears was to get the outer diameter to within 0.002″. Further, it required depthing the teeth to 1/32″ == 0.625″ (the precise measurement of the depth of the teeth) rather than cutting them a hair deeper. And I’m suspicious the Sherline divider may not… Read more

  • No, I haven’t forgotten about the gear cutting. I just haven’t been having a lot of luck.

    No, I haven’t forgotten about the gear cutting. I just haven’t been having a lot of luck.

    It probably doesn’t help that I have no idea what I’m doing. Though I do have all my fingers and toes. So there’s that. So today, after getting the M3 to M2 adapter, the M2 to Sherline adapter, and hooking up the Sherline 4-jawed chuck to the larger 7″ lathe, I went to round the… Read more

  • Wire forms.

    Wire forms.

    So if you’ve been watching my Quick Videos you know I’ve been building a lot of circuits on prototype boards. I also took the liberty of 3D printing a couple of useful tools to help measure and bend wire. The first on the left helps measure lengths of wire; each wire is measured in each… Read more

  • And now the second video has been released!

    And now the second video has been released!

    So, as promised, about a month later, the second video in my series of videos explaining how computers work from the ground up. And I mean truly, the ground up; on a breadboard next to me I have a working 1-bit adder circuit made entirely out of 10KΩ resistors, 2N3904 transistors, a few LEDs and… Read more

  • I confess to a mistake in the first video.

    I confess to a mistake in the first video.

    Of course one of the purposes of the “Introduction to Digital Computers” video series is to create a series of videos which describe how computers work from a transistor level–and starting with NPN transistors so in theory you could build this yourself. Because the idea is that I want computers not to be this strange… Read more

  • Using an Arduino to verify your web site is running.

    Using an Arduino to verify your web site is running.

    We’ve been having problems with our Internet connection, and I also maintain an e-commerce web site which I’d like to make sure is working correctly. This quick little hack uses the following parts to periodically check that your web site is running: Arduino-compatible Adafruit Metro 328 Ethernet Shield for Arduino 9 VDC power adapter Arduino-compatible… Read more

  • Another day, another four gears. And tales of woe.

    Another day, another four gears. And tales of woe.

    So one downside of the superglue arbor is that you really need to clean up the end of the arbor holding your gear–and you need to apply enough glue to get the gear to stick to the arbor. More than once today I had wheels fall off the arbor–and that led to… well, complications. I… Read more

  • I may still not quite know what I’m doing–but at least I got a gear.

    I may still not quite know what I’m doing–but at least I got a gear.

    So I drew and cut out several blanks from the 1/8th inch aluminum (and I confess I had to do this several times, by the last blank I was very close to the line) using a scroll saw and a jeweler’s blade. I then perfected them on the Sherline Lathe to the correct diameter of… Read more

  • I’ll be the first person to confess I have no idea what I’m doing here.

    I’ll be the first person to confess I have no idea what I’m doing here.

    First, let me observe that I’m fascinated by all things which calculate. That means computers, of course–from a desktop computer to mobile devices to Arduinos and other 8-bit computers. But that also means wiring transistors which can calculate things, and that means mechanical calculators: Orreries, Tellurions, mechanical adders–all of these things fascinate me as well.… Read more

  • Announcing a new Quick Video: Gates

    Announcing a new Quick Video: Gates

    Here’s the thing. I started with NPN transistors because my intent is not to start with some sort of weird theoretical “see these diagrams, that’s why it works” nonsense. I think one thing that is sorely missing from computer science is the hands-on part: the part where you actually touch something tangible and see it… Read more

  • First release video in the new series now released!

    First release video in the new series now released!

    I did some minor tweaks and reshot the opening sequence. This first in a series of videos will attempt, over the next few months, illustrate the design of a basic 8-bit computer built from transistors on up. The entire series can be found on YouTube, and linked to the new Videos section of this blog.… Read more

  • What I’ve been doing with my time.

    What I’ve been doing with my time.

    Okay, I confess I’ve left the gear cutting stuff on the back burner while I recover from a bug I picked up while in Mexico. During my spare time I’ve been working towards a series of videos which I hope to post on this site that discuss various topics in computer science. The goal of… Read more

  • Administrative: the velocity of my posts.

    Administrative: the velocity of my posts.

    I love computers. I’ve always been fascinated by computers, by the things you can do with computers, and by making things in general: hardware, software, networks, servers, user interfaces. I also have a love of mechanical things: watches, clocks, orreries, mechanical adding machines: all the things we use and have used in the past to… Read more

  • The Earth-Moon Orrery: another update.

    The Earth-Moon Orrery: another update.

    So the biggest problem, apparently, when it comes to cutting gears, is just getting all the fiddly bits together to make your gear cutting system. In my case, I’m starting with a Sherline mill, and I’m adding a CNC rotary table, a 90 degree table, and a 1 inch arbor to mount the gear cutters… Read more

  • User Interface Design Part 6: … and the rest.

    User Interface Design Part 6: … and the rest.

    Now that we’ve designed our interface by designing our visual language and defining the nouns and verbs, we’ve laid out the screens using that visual interface, and built some of the basic building blocks: the code to draw our interface elements and the code to manage our screen, all that is left to do is… Read more

  • User Interface Design Part 5: Common Code and Handling The Screen

    User Interface Design Part 5: Common Code and Handling The Screen

    In the last article I covered the “Model-View-Controller” code; the way we can think about building interfaces by separating our code into the “model”–the code that does stuff–from the “view”–the code that draws stuff–and the “controller”–the code that controls the behavior of your code. And we sketched the model code: the low level code which… Read more

  • User Interface Design Part 4: The Model-View-Controller paradigm

    User Interface Design Part 4: The Model-View-Controller paradigm

    Thus far we’ve talked about designing a user interface: the visual language that tells users what they can do, the elements of the language (nouns and verbs), the way these things contribute to consistency and discoverability and how they can be used to create a user interface that seems… inevitable. Simple. Invisible. Where this attention… Read more

  • User Interface Design Part 3: Sketching the rest of our interface.

    We have a design language of sorts. We have some simple code. We have an idea of the functions we wish to implement for our Arduino-based thermostat. Now let’s use that design language and lay out the rest of our screens. Full disclosure. For any complex UI, and let’s be honest: this is a bit… Read more

  • User Interface Design Part 2: Sketching our Interface.

    User Interface Design Part 2: Sketching our Interface.

    Last time we discussed the theory of user interface design. The idea that user interfaces form a sort of language, complete with nouns and verbs and modifiers. That user interfaces need to be discoverable and consistent, and that parts of discoverability means defining affordances: things the user can see and think “oh, that must be… Read more

  • User Interface Design Part 1: Defining Our Visual Language

    I have always wanted to write a series of articles on user interface design from the ground up, but I’ve never seem to have the time. Well, it’s time to take the time, and now that I have this beautiful little 2.8″ TFT Touch Shield that thus far I’ve been using to show how to… Read more