Heavily Hacked Printer For DIY PCBs

Sometimes we get tips that only leave us guessing as to how — and sometimes why — a project was built. Such is the case with this PCB printer; in this case, the build specifics are the only thing in question, because it puts out some pretty impressive PCBs.

All we have to go on is the video after the break, which despite an exhaustive minutes-long search appears to be the only documentation [Androkavo] did for this build. The captions tell us that the printer is built around the guts from an Epson Stylus Photo 1390 printer. There’s no evidence of that from the outside, as every bit of the printer has been built into a custom enclosure. The paper handling gear has been replaced by an A3-sized heated flatbed, adjustable in the Z-axis to accommodate varying board thicknesses. The bed runs on linear rails that appear custom-made. Under the hood, the ink cartridges have been replaced with outboard ink bottles in any color you want as long as it’s black. The video shows some test prints down to 0.1 mm traces with 0.1 mm pitch — those were a little dodgy, but at a 0.2 mm pitch, the finest traces came out great. The boards were etched in the usual way with great results; we wonder if the printer could be modified to print resist and silkscreens too.

[Androkavo] seems to have quite a few interesting projects in his YouTube channel, one of which — this wooden digital clock — we featured recently. We’d love to learn more about this printer build, though. Hopefully [Androkavo] will see this and comment below.

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Rosalind Franklin Saw DNA First

It’s a standard science trivia question: Who discovered the structure of DNA? With the basic concepts of molecular biology now taught at a fairly detailed level in grade school, and with DNA being so easy to isolate that it makes a good demonstration project for school or home, everyone knows the names of Watson and Crick. But not many people know the story behind one of the greatest scientific achievements of the 20th century, or the name of the scientist without whose data Watson and Crick were working blind: Rosalind Franklin.

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Portable Pi And Fresh Breath

There’s a long history of building things in Altoid tins, but the Pi-Tac 1.0 uses a Pi Zero W inside a Tic-Tac box. In addition to the processors, there is a tiny OLED display and a battery controller. According to a Reddit post, [Deathonater] plans to use it as a WiFi access point.

The display and the battery/power controller are from AdaFruit. You can find some sample code for the battery controller if you want to duplicate the design. You can also opt for an enhanced version that can report the battery state readily.

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Tiny, Wearable 8-Bit VT100 Terminal

In the modern era of computing, the end-user is often quite far removed from the machine they’re using. At least in terms of abstraction levels, the user experience of most computers, smart phones, and the like are very far away from the zeros and ones. If you need to get down to that level though, you’ll have to make your way to a terminal somehow, and reminisce fondly about the days when everything was accessed through a serial line.

Nowadays, some harmless nostalgia is often accompanied by a challenge as well, as [Nick] demonstrated with his tiny serial terminal. It mimics the parsing and rendering of a VT100 console using an Arduino Uno and a 1″x1″ TFT screen. His goal was to make it wearable like a wristwatch would be, using two buttons as an HID device. With the size and simple interface, [Nick] also explores the possibility of mounting such a terminal to a pair of glasses.

While not everyone may want to interact with a serial terminal with only two buttons, it’s certainly a great demonstration of what is possible when it comes to implementing retro software in unique ways. There have been serial terminals implemented in many other unique places as well, such as old oscilloscopes and replicas from popular video games.

Write Your Own X86 Bootloader

What if you want to make a very lean machine and do without any operating system? Or maybe you want to try to write your own OS, even just for the challenge or fun? Maybe you were reading up on a cool OS architecture and thought to yourself, “I can write that!”. Well, before diving into your code, you’d first have to write something called a bootloader.

A bootloader is code that runs early on in a PC’s, Mac’s, Raspberry Pi’s or microcontroller’s boot sequence, before anything like an operating system is up. Often its job is to set up minimal hardware, such as RAM, and then load the OS or your embedded code.

[Alex Parker] has written a three-part series of clear blog posts that make writing the bootloader part easy, at least for x86 machines. And the nice thing is that you don’t need an x86 to get started. He does it on a Mac using the QEMU processor emulator, though he also talks about doing it under Windows and Linux.

In the first part of the series, the bootloader leaves you in the x86’s real mode, with 16-bit instructions and access to one megabyte of memory — think pre-80286 days, or 1982 for those of us who were computing back then. To prove it works, he uses BIOS calls to display “Hello world!”. This also shows that through the BIOS, you have a set of peripherals you can work with.

In the second part, he shows how to set up 32-bit protected mode and a Global Descriptor Table, making access to a large amount of memory easier.

In the first two parts, the code is written in assembly, so in the third part he finishes the series by showing how to load C++ code into memory and execute it. That C++ code would of course be your application, which we’ll leave to your imagination.

It’s reasonably rare to write bootloader code for a desktop computer — much less so for microcontrollers. For instance, [Dmitry Grinberg] wrote his own bootloader so that he could have encrypted ROM images for his AVR on USB. And we’ve talked about [Lady Ada]’s guide to burning Arduino bootloaders. But if you want to get down to the bare metal on your x86, the bootloader is the place to start. And it’s not so bad.

Don’t Miss The Bus: A One-Day Build

Sometimes the most satisfying hacks are those that spring from a situation where resources are limited, either by choice or by chance. Constraints tend to stir the creative juices.

Serial Hackaday poster [limpkin] limited himself to a one-day build with what he had on hand for this bus-route countdown timer. Full points for actually building something useful, and extra credit for making something to keep his wife from being late for work.

The principle is simple: scrape a web page to find out how much time is left before either of two busses leaves his wife’s stop, and display the number of minutes left on a huge LED display. The parts bin gave up everything needed, including an ESP8266, a boost converter, a charge controller, and the display and driver. We’re skeptical that the PCB was fabricated the same day; looks like [limpkin] is only counting the design and coding time in his 10-hour build. Still, it’s a testament to what’s possible with a deep inventory and the skills to put it to use.

Check out some of [limpkin]’s other hacks, like this Formula-E race car PCB or his adventures in laundry larceny. Oh, and he also used to write for Hackaday.

Tinning Solution From The Hardware Store

Making your own printed circuit board at home often leads to a board which looks homemade. Exposed copper is one of the tell-tale signs. That may be your aesthetic and we won’t cramp your style, but exposed copper is harder to solder than tinned copper and it likes to oxidize over time. Tinning at home can bring you a step closer to having a full-featured board. In the video after the break, famed chemist [nurdrage] shows us how to make tinning solution at home in the video below the break.

There are only three ingredients to make the solution and you can probably find them all at a corner hardware store.

  • Hydrochloric acid. Also known as muriatic acid.
  • Solid lead-free solder with ≥ 95% tin
  • Silver polish containing thiourea

Everything to pull this off is in the first three minutes of the video. [nurdrage] goes on to explain the chemistry behind this reaction. It doesn’t require electricity or heat but heat will speed up the reactions. With this kind of simplicity, there’s no reason to make untinned circuit boards in your kitchen anymore. If aesthetics are very important, home tinning yourself allows you to mask off certain regions and have exposed copper and tin on the same board.

[nurdrage] is no stranger to Hackaday, he even has an article here about making your own PCB etchants and a hotplate to kick your PCB production into high gear.

Thanks for the tip, [drnbutyllithium].

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