PaperLedger: An E-Ink Cryptocurrency Ticker

For a long time it seemed like e-ink displays were outside the reach of us lowly hackers, as beyond the handful of repurposed Kindles that graced these pages, we saw precious few projects utilizing this relatively exotic display. But that’s changed over the last couple of years, and we’re thrilled to start seeing hackers bend this incredible technology to their will.

A perfect example is PaperLedger, an entry into the 2019 Hackaday Prize by [AIFanatic]. This wireless device is designed to display the current price of various cryptocurrencies on its 2.9-inch e-ink screen and provide audible price alerts with its built-in speaker. It even has a web portal where users can configure the hardware or view more in-depth price information.

The PaperLedger is based on the TTGO T5 V2.2 ESP32, but it looks like [AIFanatic] is in the process of spinning up a new board for the MIT licensed project to address some nagging issues for this particular application. Unfortunately, it doesn’t look like there are any pictures of the new board yet, but a description of the changes on the Hackaday.IO page shows that most of the work seems to be going into improving support for running on batteries.

Even if you’re not interested in cryptocurrency, the PaperLedger looks like a fantastic little e-ink monitor for pretty much anything else you’d like to keep a close eye on. The GPLv3 licensed firmware is available on the project’s GitHub page, so expanding or completely changing the device’s functionality shouldn’t be too tricky for anyone with a desire to do so and a working knowledge of C++.

We’ve seen several projects using the various TTGO boards that mate an ESP32 with a display at this point, and it looks like a great platform to check out if you want to push some data to a little WiFi screen with the minimum amount of hassle.

Measure Your YouTube Importance

How do you hack your motivation? Do you put red marker Xs on a paper calendar every day you exercise? Do you use an egg timer to sprint through dozens of emails? Do you lock all the doors and shut off your data to write some bulletproof code? If you are [Hulk], you build a YouTube Desktop Notifier showing his YouTube subscribers and views. This is his ticket to getting off the couch to make a video about just such a device. There is something poetic about building a mechanism to monitor its own success making a feedback loop of sorts. The page follows the video, so anyone who wants to build their own doesn’t have to scribble notes while pausing the video which is also posted below the break.

The hardware list is logical, starting with a NodeMCU module programmed through the Arduino IDE. Addressable 7-segment displays show the statistics in red, but you can sub in your preferred color with the back-lighting LEDs. It should be possible to share the CLK pins on the displays if you are important enough to need more digits. [Hulk] already outlined a list of improvements including switching to addressable backlights and adding daily and monthly tracking.

Monitoring online values without a computer monitor is satisfying on a level because it shows what motivates us, whether that is Bitcoin or the weather.

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Prusa Printer Gets An LCD-ectomy, Gains A VFD

What’s wrong with the OEM display on a Prusa I3 Mk3? Nothing at all. Then why replace the stock LCD with a vacuum fluorescent display? Because VFDs are much, much cooler than LCDs.

(Pedantic Editor’s Note: VFDs actually run a little warm.)

At least that’s the reasoning [Scott M. Baker] applied to his Prusa upgrade. We have to admit to a certain affection for all retro displays relying on the excitation of gasses. Nixies, Numitrons, and even the lowly neon pilot light all have a certain charm of their own, but by our reckoning the VFD leads the pack. [Scott] chose a high-quality Noritake 4×20 alphanumeric display module for his upgrade, thriftily watching eBay for bargains rather than buying from the big distributors. The module has a pinout that’s compatible with the OEM LCD, so replacing it is a snap. [Scott] simplified that further by buying a replacement Prusa control board with no display, to which he soldered the Noritake module. Back inside the bezel, the VFD is bright and crisp. We like the blue-green digits against the Prusa red-orange, but [Scott] has an orange filter on order for the VFD to make everything monochromatic. That’ll be a nice look too.

A completely none functional hack, to be sure, but sometimes aesthetics need attention too. And it’s possible that a display switch would help the colorblind use the UI better, like this oscilloscope mod aims to do.

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Apple Just Killed The VESA Mount And We Couldn’t Be Happier

After the immense failure of the 2013-era Apple Pro trash can Mac, Apple has been hard at work at the next generation of workstation desktops. This week, the new Mac Pro has been announced, and the specs are amazing: We finally can buy a professional, desktop Mac with half the storage of an iPhone. The big story isn’t the next generation of cheese-grater Macs, though: the new display, the Pro Display XDR, has killed the venerable VESA mount and we couldn’t be happier.

The VESA mount, or more correctly, the VESA Mounting Interface Standard, was created in 1997 as a mounting standard for flat panel monitors and televisions. Look on the back of your monitor, and you’ll probably find a pattern of M4 threaded inserts laid out on a 75mm or 100mm square. Larger sizes, with respectively larger thread sizes, are used for gigantic wall-mounted televisions. For the last two decades, this has been the standard for mounting monitors to stands. Now this standard faces a challenger thanks to the brave designers at Apple. Continue reading “Apple Just Killed The VESA Mount And We Couldn’t Be Happier”

Make Your Own Old School LED Displays

We live in an era in which all manner of displays are cheap and readily available. A few dollars spent online can net you a two-line alphanumeric LCD, a graphical OLED screen, or all manner of other options. Years ago however, people made do with little monolithic LED devices. [sjm4306] wanted to recreate something similar, and got down to work (Youtube link, embedded below).

The resulting device uses 0603 sized SMD LEDs, soldered onto a tiny PCB. 20 LEDs are used per digit, which can display numbers 0-9 and letters A-F. The LEDs are laid out in a pattern similar to Hewlett-Packard designs from years past. This layout gives the numerals a more pleasant appearance compared to a more-classic 7-segment design. Several tricks are used to make the devices as compact as possible, such as putting vias in the LED pads. This is normally a poor design technique, but it helps save valuable space.

[sjm4306] has developed a breadboard model, and a more advanced version that has a pad on the rear to mount a PIC16F88 microcontroller directly. We look forward to seeing these modules developed further, and can imagine they’d prove useful in a variety of projects.

For reference, check out these Soviet-era 7-segment displays. Video after the break.

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Ferrofluid Display Fuels The Fun, And The Procrastination

When deadlines loom and your future is on the line, do what top college students through the ages have always done: procrastinate! [Simen] and [Amund] did that in grand style by starting a YouTube channel, delightfully and aptly named “Applied Procrastination”, wherein they plan to avoid their responsibilities as long as possible in favor of making a large-scale ferrofluidic display panel. (Video, embedded below.)

We suppose we should encourage them to hit the books, but honestly they look like they’re having much more fun and learning more than they would in class. The idea isn’t new; we’ve seen ferrofluid clocks before, after all. [Amund] and [Simen] have grander plans for their display, but they’re wisely starting small with basic experiments. They had an early great idea to use a double-pane window as a tank for their display, but coatings on the inside of the glass and the aluminum frame conspired to cloud the display. They also did some tests to make sure they can control 252 electromagnets safely. They did manage to get a small test display working, but really the bulk of the video is just them playing with magnets and ferrofluid. And again, we’re OK with that.

It looks like this is going to be an interesting project, with hopefully regular updates to the channel now that summer break is upon us. Unless they find something else to do, of course.

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A Ping Pong Ball LED Video Wall

Constrained builds are often the most fun. Throw an artificial limit into the mix, like time limiting your effort or restricting yourself to what’s on hand, and there’s no telling what will happen.

[bitluni] actually chose both of those constraints for this ping pong ball LED video display, and the results are pretty cool, even if the journey was a little rough. It seems like using sheet steel for the support of his 15 x 20 Neopixel display was a mistake, at least in hindsight. A CNC router would probably have made the job of drilling 300 holes quite a bit easier, but when all you have is a hand drill and a time limit, you soldier on. Six strings of Neopixels fill the holes, a largish power supply provides the 18 or so amps needed, and an Arduino knock-off controls the display. The ping pong ball diffusers are a nice touch, even if punching holes in them cost [bitluni] a soldering iron tip or two. The display is shown in action in the video below, mostly with scrolling text. If we may make a modest suggestion, a game of Pong on a ping pong ball display might be fun.

[bitluni] says that the display is on its way to Maker Faire Berlin this weekend, so stop by and say hi. Maybe he’ll have some of his other cool builds too, like his Sony Watchman Game Boy mashup, or the electric scooter of questionable legality.

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