Misc Hacks

4164 Articles

Working LEGO Space Computers Are A Chip Off The Old Block

August 4, 2021 by No comments

We all have our favorite classic LEGO bricks, and wouldn’t be surprised if one or more of the various space computers showed up on pretty much everyone’s list. [dyoramic] loves them so much that they built two different working versions that do different things.

The first one is about six times the size of the original brick. Inside the 3D printed case is an ESP32 and a 1.5″ OLED display. [dyoramic] wired up the top six buttons as inputs and the rest are just for looks. The screen defaults to the classic white cross on green that just sits there looking legit. But start pushing buttons and you’ll find other modes — the cross becomes a radar screen in one, the computer spits out space facts in another, there’s a falling bricks game, and finally, a time and date screen.

The second LEGO space computer build is even bigger — both were designed around the size of their screens. It has a Raspi 4 and shows a dashboard with the weather, time, date, latest xkcd, and a few cryptocurrency prices. [dyoramic] has an even bigger version in the works that will use a 720 x 720 screen and a handful of brown key switches as inputs. We can’t wait to see that one! For now, check out the build and demo of the first two after the break.

What can’t you do with LEGO? It feels like we’ve seen it all, from cameras to microscopes to continuously variable transmissions. Wouldn’t you love to drive one of those around the block?

Continue reading “Working LEGO Space Computers Are A Chip Off The Old Block” →

EXPS/2 Keyboard Adapter Translates PS/2 And USB To MSX

August 2, 2021 by 10 Comments

Say what you will about suitcase computers, but at least most of them still have their keyboards with them. [danjovic] has this vintage Brazilian computer from the 1980s called a Gradiente Expert. These were MSX machines with Z80 chips that ran BASIC, DOS, and CP/M, and they looked like state-of-the-art dual-deck stereo systems. You can still find them pretty easily, but sadly, most of them have lost their rad mechanical keyboard with its giant arrow keys and proprietary connector.

If you now want to get one of these awesome pieces of computing history and would like to be able to talk to it, [danjovic] has you covered with the open-source EXPS/2 keyboard adapter. It will allow you to connect either a PS/2 keyboard or a USB keyboard in fallback mode to the Expert using an ATMega328P and a bespoke DIN-13 to DB-13 cable. As it turns out, there’s a wealth of information on MSX keyboard matrices out there.

How much do you know about the USB keyboard interface? If you want a warehouse of information delivered to your brain in the most pleasant way possible, go watch [Ben Eater] break it down with pen and paper.

Living The Dream: New PCB For A Dirt-Cheap Calculator Watch

August 1, 2021 by 6 Comments

Well, this hack has us tickled pink. We love the idea of buying some really cheap piece of technology and doing something amazing with it, and this is a textbook example of that. [davedarko] found the cutest little calculator watch on Ali Express and is working on making a new PCB for it. The plan is to use an ARM processor and Arduino and add a few extras like 24-hour mode and a pink (or potentially RGB) backlight. The new brain will be an ATSAML22G18A, which has an on-board LCD controller and exactly one I/O pin to spare without charlieplexing the buttons.

One of [davedarko]’s primary goals is to keep the LCD and figure out how to talk to it. The first order of business was reverse engineering the watch’s LCD controller by sussing out the secrets from beneath the black blob of epoxy. This was an eye-opening experience as [davedarko] had never worked directly with LCDs before. A strange reading made him bust out the oscilloscope. Long-ish and informative story short, [davedarko] found out that it uses a bias of 1/2 for generating the wave necessary to multiplex the segments and keep the signal alternating. This is definitely one to watch!

We love timepieces around here and have seen all kinds of hacks, especially on Casio watches. Want dark mode? Done. Enable the hidden countdown timer? We’ve got that, too. And have you ever wondered just how water-resistant the F91W is?

Step ‘n Snack Fanny Pack Motivates With M&Ms

July 30, 2021 by 5 Comments

[Sam March] has made a lot of different kinds of things, many of which have appeared on these very pages. Nowadays he wants to get the viewers more involved in his projects, so he started doing a monthly collaboration with YT viewers. Basically, he gives a prompt, and people comment with their wild and crazy ideas on the topic. Whoever has the winning idea gets the finished build. The maiden prompt was ‘fanny pack’, and you can check out the result in the build video (embedded below).

Someone suggested a Reese’s cup-dispensing fanny pack that gives you one cup for every 10,000 steps you take. We like what [Sam] did with that idea, because it’s way more practical — M&Ms are the original travel candy, and this way, you get to eat chocolate way more often. Depending on your sweet tooth, Reese’s Pieces would be a good compromise.

[Sam] figured out that the average human burns one calorie for every 25 steps, and that the average plain M&M is worth four calories, so he built a fanny pack with a step counter that dispenses one M&M for every 100 steps taken using a tiny auger. It’s calorie-neutrality!

You might be wondering if [Sam] made the fanny pack, too, or used something store-bought. The answer is neither: at some point in the build process, a company graciously offered to make a fanny pack with a special compartment in the bottom for the M&M dispenser. If you want to build one of these for yourself, you can get the CAD file for the milled base, the screw, the hopper, and the lid plus the code and also the gerbers on GitHub. We see a place for the sewing pattern, but as of now, the folder is empty. Be sure to check out the build and demo video after the break as [Sam] hits the town in a screaming set of neon workout wear to test the dispenser.

Most of the M&M-based projects we see around here are designed to sort by color. Here’s one that searches for the holy grail — peanut M&Ms that didn’t get a peanut. Continue reading “Step ‘n Snack Fanny Pack Motivates With M&Ms” →

3D-Printed Tooling Enables DIY Electrochemical Machining

July 29, 2021 by 10 Comments

When it comes to turning a raw block of metal into a useful part, most processes are pretty dramatic. Sharp and tough tools are slammed into raw stock to remove tiny bits at a time, releasing the part trapped within. It doesn’t always have to be quite so violent though, as these experiments in electrochemical machining suggest.

Electrochemical machining, or ECM, is not to be confused with electrical discharge machining, or EDM. While similar, ECM is a much tamer process. Where EDM relies on a powerful electric arc between the tool and the work to erode material in a dielectric fluid, ECM is much more like electrolysis in reverse. In ECM, a workpiece and custom tool are placed in an electrolyte bath and wired to a power source; the workpiece is the anode while the tool is the cathode, and the flow of charged electrolyte through the tool ionizes the workpiece, slowly eroding it.

The trick — and expense — of ECM is generally in making the tooling, which can be extremely complicated. For his experiments, [Amos] took the shortcut of 3D-printing his tool — he chose [Suzanne] the Blender monkey — and then copper plating it, to make it conductive. Attached to the remains of a RepRap for Z-axis control and kitted out with tanks and pumps to keep the electrolyte flowing, the rig worked surprisingly well, leaving a recognizably simian faceprint on a block of steel.

[Amos] admits the setup is far from optimized; the loop controlling the distance between workpiece and tool isn’t closed yet, for instance. Still, for initial experiments, the results are very encouraging, and we like the idea of 3D-printing tools for this process. Given his previous success straightening his own teeth or 3D-printing glass, we expect he’ll get this fully sorted soon enough.

Scanning Medium Format Film On A 35mm Scanner

July 28, 2021 by 6 Comments

Scanning film is great for archival purposes as well as sharing said photos digitally. However, if you’re scanning 120 film, aka medium format, it can be expensive to get the requisite hardware. 35mm scanners are comparatively more common, so [Christian Chapman] decided to modify one to suit medium film instead.

The hack is for the Plustek 8100, and requires modifying the scanner in two ways. Firstly, the driver has to be scanned to sweep a longer range to take into account the bigger film. Secondly, a part of the film carriage has to be replaced so it doesn’t show up in the scanners field of view.

The former is achieved by using the sane-genesys scanner software backend, which can be easily modified to adjust the scan length values appropriately. The latter is achieved via 3D printing replacement components that fit without blocking the requisite area.

It’s a tidy hack and one that allows [Christian] to both scan medium format film as well as overscan 35mm film to capture details from the sprocket hole area. We’ve seen fully custom film scanner builds before, too. If you’ve built your own scanner, be sure to drop us a line!

Emulating The IBM PC On An ESP32

July 28, 2021 by 60 Comments

The IBM PC spawned the basic architecture that grew into the dominant Wintel platform we know today. Once heavy, cumbersome and power thirsty, it’s a machine that you can now emulate on a single board with a cheap commodity microcontroller. That’s thanks to work from [Fabrizio Di Vittorio], who has shared a how-to on Youtube. 

The full playlist is quite something to watch, showing off a huge number of old-school PC applications and games running on the platform. There’s QBASIC, FreeDOS, Windows 3.0, and yes, of course, Flight Simulator. The latter game was actually considered somewhat of a de facto standard for PC compatibility in the 1980s, so the fact that the ESP32 can run it with [Fabrizio’s] code suggests he’s done well.

It’s amazingly complete, with the ESP32 handling everything from audio and video to sound output and keyboard and mouse inputs. It’s a testament to the capability of modern microcontrollers that this is such a simple feat in 2021.

We’ve seen the ESP32 emulate 8-bit gaming systems before, too. If you remember [Fabrizio’s] name, it’s probably from his excellent FabGL library. Videos after the break. Continue reading “Emulating The IBM PC On An ESP32” →