Articles by Al Williams

You think of breadboards as being a flexible way to build things — one can easily add components and wires and also rip them up. But MIT researchers want to introduce an actual flexible breadboard called FlexBoard. The system is like a traditional breadboard, but it is literally flexible. If you want to affix your prototype to a glove or a ball, good luck with a traditional breadboard. FlexBoard makes it easy. You can see a short video below and a second video presentation about the system, also.
The breadboard uses a plastic living hinge arrangement and otherwise looks more or less like a conventional breadboard. We can think of about a dozen projects this would make easier.
What’s more, it doesn’t seem like it would be that hard to fabricate using a 3D printer and some sacrificial breadboards. The paper reveals that the structures were printed on an Ender 3 using ePLA and a flexible vinyl or nylon filament. Want to try it yourself? You can!
We know what we will be printing this weekend. If you make any cool prototypes with this, be sure to let us know. Sometimes we breadboard virtually. Our favorite breadboards, though, have more than just the breadboard on them.

[embedded content]
[embedded content] […]

If you want a book on network programming, there are a few classic choices. [Comer’s] TCP/IP books are a great reference but sometimes is too low level. “Unix Networking Programming” by [Stevens] is the usual choice, but it is getting a little long in the tooth, as well. Now we have “Beej’s Guide to Network Programming Using Internet Sockets.” While the title doesn’t exactly roll off the tongue, the content is right on and fresh. Best part? You can read it now in your browser or in PDF format.
All the topics you’d expect are there in ten chapters. Of course, there’s the obligatory description of what a socket is and the types of sockets you commonly encounter. Then there’s coverage of addressing and portability. There’s even a section on IPV6.

After covering the most common socket API calls, there is a simple example. Then Chapter 7 covers “slightly advanced techniques.” That includes things like the select API call, partial sends, and broadcast packets. Chapter 9 is just man pages which are handy if you have the printed reference on an airplane. Overall, a good modern treatment of the topic.
While the socket API originated at Berkely, just about every network stack looks the same more or less, so if you learn these calls, you’ll do fine on whatever operating system you like, including many microcontrollers.
Usually, when we are looking at networking, our eyes are focused lower in the stack. But if you aren’t reverse engineering, the API is definitely the way to go. […]

[Bytewelder] fondly remembers the Palm III and Sharp HC-4500, so taking on the design of Decktility, a custom handheld cyberdeck , was a natural next step. The blog post goes into much detail about the design decisions and challenges throughout the project. The end result, though, looks great.
The device uses a Raspberry Pi CM4 and an IPS touchscreen. The bulk of the design work was to get the power system working. There is a custom FET board and an Arduino that manages charging and battery state.
The 3D-printed case is compact, and the whole thing weighs about 375 grams. You can replace the batteries after their 6-hour stint or charge them in situ via USB-C.
The battery charger is of particular interest. [Bytewelder] wanted to integrate power management but didn’t want to write custom Linux drivers. The solution was simple: have the Arduino emulate an existing power management device with Linux driver support. In this case, the power management system looks to the Raspberry Pi like an LTC294x device, so the normal Linux OS knows how to handle it.
If you are really worried about batteries, you can swap processing power for battery life. This build reminds us of some of the organizers that were popular once upon a time. We have a soft spot for decks that look like retro computers or even if they could have been. […]

With all the hype about ChatGPT, it has to have crossed your mind: how can I make it control devices? On the utopia side, you could say, “Hey, ChatGPT, figure out what hours I’m usually home and set the thermostat higher when I am away.” On the dysfunctional side, the AI could lock you in your home and torment you like some horror movie. We aren’t to either extreme yet, but [Chris] couldn’t resist writing a ChatGPT plugin to control a Raspberry Pi. You can see a video of how it turned out below.
According to [Chris], writing a ChatGPT plugin is actually much simpler than you think. You can see in the video the AI can intuit what lights to turn on and off based on your activity, and, of course, many more things are possible. It can even detect snoring.

In a bit of self-referential work, ChatGPT actually wrote a good bit of the code required. Here’s the prompt:
Write me a Python Flask API to run on a Raspberry Pi and control some lights attached to GPIO pins.
I have the following lights:
Kitchen: pin 6Bedroom: pin 13Dining table: pin 19Bathroom: pin 26Lounge: pin 5
I want the following endpoints:
get lights – returns the list of lights along with their current statepost toggle_light – switches a light on or off
It also took the code and generated an OpenAPI file for it automatically. Pretty slick!
Of course, this is just the tip of the iceberg of what you could do with a system like this. We are both excited and a little nervous about what will happen when AI takes over more real-world hardware.
As we’ve pointed out, ChatGPT is great for tedious programming tasks, but you do need to verify that it is getting things right. We aren’t going to be put out of work by AI — at least, not yet.
[embedded content] […]

If you have three hours and you want to learn the fundamentals of semiconductors, [Tiny Tapeout] has something for you: An introduction to SiliWiz. You’ll also need the SiliWiz software (or use it online), which resembles the kind of tools that chip designers use but is meant for students to use as a learning tool
Using SiliWiz, you create layers on a virtual device, and you can use Spice to view the results. The tutorial is meant to be high-level and is suggested for students aged 14 or over (but we liked it and we are quite a bit older than that). Some more advanced material is also available at the same site.

SiliWiz is easy to use. You build layers of n or p material, metal, or polysilicon. A slider lets you show a cross-section at a particular point. You label metal endpoints and use the simulation to plot the results. As expected, the process mimics a simplified version of the open-source Skywater process design kit.
We’ve had experience designing and doing failure analysis on ICs, and it is truly a different world. For example, resistors created with diffusion or polysilicon are typically difficult to make precise (that’s why you see laser-trimmed resistors on expensive precision components). However, because photolithography is very precise, the ratio of two capacitors can be a very dependable value even if the absolute value of each capacitor is less predictable. So for a digital-to-analog converter, for example, on a PCB you might use resistors, while on an IC, you are more likely to use capacitors where the ratio of values is well-known. Getting that kind of precision on a PCB with discrete capacitors would be tough.
Designing chips is not easy, and you usually want to start at a higher level and then translate your idea into silicon. SiliWiz isn’t going to give you a directly buildable design, but it will help you understand the IC design and fabrication process better.
We’ve covered the Skywater PDK before. We highly suggest you check out [Matt Venn’s] Zero to ASIC workshop if you plan to take this further. […]

These days, our video cards are actually as powerful as yesterday’s supercomputer and our monitors are bigger than the TVs most of us had as kids. But how did we get there? [RetroBytes] covers computer displays starting with the Colossus computer to today.
Back in the days of Colossus, of course, a display was actually a TeleType-like device printing on a roll of paper. The Manchester Baby actually had a crude display which was actually a Williams tube (no relation) that used phosphor persistence to store data. You could physically see memory on the tube or monitor it on a parallel tube — an early form of memory-mapped display.

Early commercial computing used cards and often used a typewriter-like device as a console. Timesharing allowed people to use computers directly and drove innovation in user interface technology. Of course, displays didn’t start out like the ones we use today. [RetroBytes] shows an old video game that uses vector display technology which was a common way screens worked on early computers. Essentially, the device was an XY oscilloscope driven by the computer.
TeleTypes gave way to “glass TeleTypes” or terminals. Power supplies and CRTs made these heavy, but they were the user’s window into the computer. Of course, eventually, the terminal would become the computer.
The video ends at the terminal. Of course, today, not only is the terminal the computer, but the screen is almost certainly a flat screen. The way a modern VGA card works is a lot different than an old text-based terminal. Not that we didn’t see old graphics systems, complete with light guns. Even if you want a duplicate terminal these days, you might want to scale back on the size a little. […]

Graphene isn’t easy to produce at scale. But making small batches of graphene is doable in a few ways. [Robert Murray-Smith] decided to try producing “flash graphene.” This requires a big capacitor bank that is moderately expensive, so he decided to explain a different technique he read about using an ordinary laser cutter. Check it out in the video below.
We were a little disappointed that he didn’t actually make any graphene this time. He has, however, used other methods in other videos to create some type of graphene. In fact, he has many similar videos going back quite a ways as well as applications with concrete, capacitors, and more. We understand that this method doesn’t produce monolayer graphene, but actually creates a graphene “foam” with interesting properties. [Robert] talks about recent papers that show you can grow graphene on things other than Kapton tape using this method.

If you decide you’d like to try this out, we’d love to see your results. [James Tour] from Rice University has a video about laser-induced graphene that might help you, too. We’ve seen [Zachary Tong] using this method, as well. The flash process is interesting, too, because when compared to most other methods it seems more scalable.
[embedded content] […]

You can babysit your 3D printer 100% of the time, or you can cross your fingers and hope it all works. Some monitor their printers using webcams, but [Simit] has a more stylish method of keeping tabs on six 3D printers.
The idea is to use a 3D printed hex LED display found online. Adding an ESP32 and Home Assistant allows remote control of the display. The printers use Klipper and can report their status using an API called Moonraker. Each hexagon shows the status of one printer. You can tell if the printer is online, paused, printing, or in other states based on the color and amount of LEDs lit. For example, a hex turns totally green when printing is complete.
Once you have a web API and some network-controlled LEDs, it is relatively straightforward to link it together with Home Automation. Of course, you could do it other ways, too, but if you already have Home Automation running for other reasons, why not?
We have seen other ways to do this, of course. If you need an easy monitor, the eyes have it. If you don’t use Klipper, OctoPrint can pull a similar stunt. […]

Today if you want to reproduce a big schematic or a mechanical drawing, you just ask it to print or plot from the CAD model. But back in the day, you drew on big sheets at a drafting table. How do you make copies? Sure, there were a few large-format copiers, but they were expensive. A more common method was to use a heliographic copier which, often but not always, resulted in a blueprint — that is a blue page with white lines or vice versa. These days, you are more likely to see a blueprint as an artistic wall hanging, and since [Basement Creations] wanted some, he figured out how to make them with a 3D printer.
These prints aren’t really blueprints. They use the printer as a plotter and deposit white ink on a blue page. In the video below, he shows a number of ways to use a printer to create interesting wall art, even if you want it to be bigger than the print bed. Some of the wall art uses multiple 3D printed parts, and others use the printer as a plotter.

To join the printed pieces, he uses a soldering iron to weld them together. We wondered if it might be worthwhile to make overlapping pieces to glue which would also help with alignment. Plotting is great for making PCBs, of course, and while you could invert the image and print blue on white paper, it won’t really look like a blueprint.
You’d think mounting a pen to a printer is easy, and there are a lot of designs online. However, the pen needs to be rigid, and unless your bed is completely trammed, the pen needs some ability to move up and down to maintain pressure. The third mount he creates is pretty over-engineered, with two bearings and rods allowing the pen to ride up and down. It seems like a lot, but it also seems to work well. The final wall art is a 3D-printed replica of the James Webb Telescope that uses real mirrors to mimic the iconic look of that space-borne observatory.
This is one of those projects that isn’t a completely new idea, but we did like the variety of ideas and tips. Presumably, you could also join the blueprint paper to make larger ones.
This isn’t the first James Webb replica we’ve seen, but the last one had a wooden base. Maybe you could point your telescope replica at a faux moon.
[embedded content] […]