I’ll See Your Seven-Segment Mechanical Display And Raise You To 16 Segments

October 8, 2022 by Dan Maloney 6 Comments

Mechanical multi-segment displays have become quite a thing lately, and we couldn’t be more pleased about it. The degree of mechanical ingenuity needed to make these things not only work but look good while doing it never ceases to amaze us, especially as the number of segments increases. So we submit this over-the-top 16-segment mechanical display (Nitter) for your approval.

The original tweet by [Kango Suzuki] doesn’t have a lot of detail, especially if you can’t read Japanese, but we did a little digging and found the video shown below. It shows a lot more detail on how this mechanism works, as well as some of the challenges that cropped up while developing it. Everything is 3D printed, and flipping the state of each of the 16 segments is accomplished with a rack-and-pinion mechanism, with the pinions printed right into each two-sided cylindrical segment. The racks are connected to pushrods that hit a punch card inserted into a slot in the rear of the display. The card has holes corresponding to the pattern to be displayed; when it’s pushed home, the card activates a mechanism that slides all the racks that line up with holes and flips their segments.

This isn’t the first multi-segment mechanical masterpiece from [Kango Suzuki] that we’ve featured, of course. This wooden seven-segment display works with cams rather than punch cards, but you can clearly see the hoe the earlier mechanism developed into the current work. Both are great, and we’re looking forward to the next segment count escalation in the mechanical display wars.

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e-paper display showing hand-drawn fonts attached to a custom controller PCB

Recycling Junk E-tags Into A LoRaWAN AQI Sensor

September 28, 2022 by Dave Rowntree 6 Comments

E-paper interfacing circuit is just a simple switched-mode power supply — Interfacing to E-paper displays is nothing to be scared of

[Aduecho] had seen those cheap eBay deals of e-paper-based pricing tags, and was wondering if they could be hacked to perform some other tasks. After splitting the case open, the controller chip was discovered to be a SEM9110, with some NFC hardware support but little else. [aduecho] was hoping to build some IoT-connected air quality indicator (AQI) units but the lack of a datasheet for SEM9110 plus no sensors in place meant the only real course of action was to junk the PCB and just keep the E-paper display and the batteries. These units appeared to be ‘new old’ stock, so there was a good chance that both would be fresh and ripe for picking.

The PCB [aduecho] came up with is mechanically the same as the original unit, but now sports a Seeed studio Wio-E5 LoRa module, which uses the STM32WLE5 from ST for the heavy lifting. This has what looks like a Semtech SX126x integrated on-die (we can’t think of a sane way an actual SX126x die could be flip-chip mounted, but you never know). Using this module is a snap, needing only very minimal antenna-matching components and a spot of decoupling to function. On the sensing side of things, a Bosch BME680 gas sensor handling the AQI measurements, and a Bosch BMI270 6-axis IMU, provides a gyro and accelerometer, for all those planned user interaction features. As can be seen from the schematic, interfacing the EPD is pretty straightforward, just a handful of parts are needed to generate the necessary bipolar gate voltages via a simple SMPS circuit. The display controller handles it all internally, programmed via an SPI interface.

One area we’re quite fond of in this project are the neat hand-drawn icons, and variable width font, giving the display a kind of note-like quality when drawn on the low-ish contrast e-paper display.

Air quality measurement projects grace these pages from time to time, like this hacked Ikea Vindriktning, and this very similar Wio-E5-based project we covered last month.

Custom Calculator Brings Us Back To The 70s

September 1, 2022 by Bryan Cockfield 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 Bryan Cockfield 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 Elliot Williams 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.

Probing CAN Bus For EV Battery Info

July 27, 2022 by Bryan Cockfield 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 Lewin Day 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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