display

237 Articles

Custom Calculator Brings Us Back To The 70s

September 1, 2022 by 7 Comments

There are certain design aesthetics from every era that manage to survive the fads of their time and live throughout history. Ancient Greek architecture is still drawn upon for design inspiration in modern buildings, the mid-century modern style from the 60s still inspires various designs of consumer goods, and the rounded, clean looking cars from the 90s are still highly desirable qualities in automotive design. For electronics, though, we like this 70s-inspired calculator that [Aaron] recently built.

The calculator hearkens back to the days of calculators like the HP-29C with its large buttons and dot-matrix display. [Aaron] built the case out of various woods with a screen angled towards the user, and it uses a LCD display similar to those found in antique calculators. The brain of the calculator is an Arduino which fits easily into the case, and [Aaron] also built the keyboard from scratch with Cherry MX-style mechanical keys soldered together into a custom shape.

The software to run the calculator is fairly straightforward, but we are most impressed with the woodworking, styling, and keyboard design in this build. [Aaron] is also still ironing out some bugs with the power supply as it uses a DC-DC converter to power the device from a single lithium battery. For those who are more fond of early 2000s graphing calculators instead, be sure to take a look at this graphing calculator arcade cabinet.

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Macintosh Classic II With E-Ink Display

August 24, 2022 by 30 Comments

As various antique computers age, it becomes increasingly hard to operate them as hardware begins to physically fail. Keeping these systems up and running often requires scavenging parts from other machines which are only becoming harder to find as time goes on. But if you throw out the requirement of using only era-appropriate components, there are some interesting ways to revive older devices with a few touches of modern tech, like this Mac Classic with a unique display.

The Macintosh Classic II was the successor to the first Macintosh computer Apple sold that had a price tag under $1000. As such, there were some lower specs for this machine such as the monochrome 512×342 display. This one has been retrofitted with an e-ink display which actually gives it some of the same grayscale aesthetic as the original. The e-ink display is driven by a Raspberry Pi which displays a replica System 7 environment and a set of photos.

While the only part of the computer that’s original is the shell at this point, the project’s creator [Dave] also built in support for the Apple Desktop Bus through an Arduino so the original Apple mouse and keyboard can be used. While it’s largely an illusion of a working Mac Classic, we still appreciate the aesthetic.

If you’re more of a classic Apple purist, though, take a look at this SE/30 which uses almost entirely original parts with the exception of a Raspberry Pi to allow it to communicate with the modern Internet.

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Hackaday Prize 2022: Saving The World, One Brew At A Time

August 5, 2022 by 10 Comments

OK, so maybe [satanistik] is overreaching with his project title “Save the Coffee, Save the World” but keeping an otherwise working coffee machine out of the landfill by hacking around its broken display is nonetheless a worthy pursuit. The juice must flow!

The busted display used a SSD1303 controller OLED module, for which the SSD1305Z is an almost-compatible module. Almost. The one glitch is that the screen is filled in the opposite direction by default. Digging through the manuals, there is a screen-direction bit to set, and tracing out the communication with a logic analyzer, it’s set the wrong way with every screen refresh. If only he could flip that one bit while it’s in transit. Time to man-in-the-middle!

While we certainly would have put a microcontroller in the game, [satanistik] goes old-school. A two-IC logic solution can do exactly the same thing, trading wires for code. The final iteration of the converter board is correspondingly spartan, but it does its one job.

So if you’ve got a Nivona coffee machine with a bum display, or perhaps an Agilent U1273A multimeter, or any other piece of equipment that needs a hard-to-find SSD1303 controller, now you have a ready-made solution. But if not, and you find yourself looking for a display that you can’t find, let this serve as an example to you – with a little (fun) effort, you can hack it back.

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Probing CAN Bus For EV Battery Info

July 27, 2022 by 8 Comments

The widespread adoption of the CAN bus (and OBD-II) in automobiles was largely a way of standardizing the maintenance of increasingly complicated engines and their needs to meet modern emissions standards. While that might sound a little dry on the surface, the existence and standardization of this communications bus in essentially all passenger vehicles for three decades has led to some interesting side effects, like it’s usage in this project to display some extra information about an electric car’s battery.

There’s not a ton of information about it, but it’s a great proof-of-concept of some of the things CAN opens up in vehicles. The build is based on a Citroën C-Zero (which is essentially just a re-badged Mitsubishi i-MiEV) and uses the information on the CAN bus to display specific information about the state of charge of the battery that isn’t otherwise shown on the car’s displays. It also includes a build of a new secondary display specifically for this purpose, and the build is sleek enough that it looks like a standard part of the car.

While there are certainly other (perhaps simpler) ways of interfacing with a CAN bus, this one uses off-the-shelf electronics like Arduino-compatible microcontrollers, is permanently installed, and has a custom case that we really like. If you’re just starting to sniff around your own vehicle’s CAN bus, there are some excellent tools available to check out.

Thanks to [James] for the tip!

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You Can Build A Giant 7-Segment Display Of Your Very Own

July 27, 2022 by 7 Comments

Sometimes you need to display a number nice and large, making it easily readable at a good distance. [Lewis] has just the thing for that: a big expandable 7-segment display.

The build is modular, allowing it to be extended from 2 to 10 digits and beyond. The digits themselves are made of 3D-printed parts assembled onto acrylic. These can then be ganged up in a wooden frame for displaying larger numbers with more digits. Individual elements are lit by addressable LEDs, and the project can be built using an Arduino Nano or an ESP8266 for control. The latter opens up possibilities for controlling the screen over WiFi, which could prove useful.

[Lewis] has built his own version for a local swim club, where it will be used as a laptimer. Other applications could be as a scoreboard in various sports, or to confuse your neighbours by displaying random numbers in your front yard.

We’ve seen a similar build from [Ivan Miranda] that served well as a workshop clock, too. Video after the break.

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HDMI Is An Attack Surface, So Here’s An HDMI Firewall

June 22, 2022 by 13 Comments

Many years of using televisions, monitors, and projectors have conditioned us into treating them as simple peripherals whose cables carry only video. A VGA cable may have an i2c interface for monitor detection, but otherwise it presents little security risk. An HDMI interface on the other hand can carry an increasing number of far more capable ports, meaning that it has made the leap from merely a signal cable to being a connector stuffed with interesting attack vectors for a miscreant. Is it time for an HDMI firewall? [King Kévin] thinks so, because he’s made one.

It’s a surprisingly simple device, because the non-signal capabilities of HDMI rely on a set of conductors which are simply not connected. This of course also disconnects the on-board EEPROM in the device being connected, so there’s an EEPROM on the firewall board to replace it which must be programmed with the information for the device in question.

The premise of HDMI as an attack surface is a valid one, and we’re sure there will be attacks that can be performed on vulnerable displays which could potentially in turn do naughty things to anything which connects to them. The main value for most readers here probably lies though in the introduction it gives to some of what goes into an HDMI interface, and in accessing the i2c interface therein.

It comes as a surprise to realise that HDMI is nearing 20 years old, so it’s hardly surprising that its hacking has quite a history.

Screenshot of the website, showing the sidebar with technology types on the left, and an entry about modifying LCD polarizers on the right, with a video showing an art piece using LCD polarizers

Alternative Display Technologies And Where To Find Them

June 1, 2022 by 13 Comments

[Blair Neal] has been working on an information database for artists and hackers – a collection of non-conventional display technologies available to us. We’ve covered this repository before, six years ago – since then, it’s moved to a more suitable platform, almost doubled in size, and currently covers over 40+ display technology types and related tricks. This database is something you should check out even if you’re not looking for a new way to display things right now, however, for its sheer educational and entertainment value alone.

[Blair] doesn’t just provide a list of links, like the “awesome-X” directories we see a lot of. Each entry is a small story that goes into detail on what makes the technology tick, its benefits and fundamental limitations, linking to illustrative videos where appropriate. It’s as if this guide is meant to give you an extensive learning course on all the ways you can visualize things on your creative journey. All of these categories have quite a few examples to draw from, highlighting individual artworks that have made use of any technology or trick in a particular way.

If you’re ever wondered about the current state of technology when it comes to flexible or transparent displays, or looked for good examples of volumetric projection done in a variety of ways, this is the place to go. It also talks about interesting experimental technologies, like drone displays, plasma combustion or scanning fiber optics. Overall, if you’re looking to spend about half an hour learning about all the ways there are to visualize something, this database is worth a read. And, if there’s a display technology the author might’ve missed and you know something about, contributions are welcome!

Someone setting out to compile information about an extensive topic is always appreciated, and helps many hackers on their path. We’ve seen that done with 3D printer resin settings and SMD part codes, to name just a few. What’s your favourite hacker-maintained database?