Computers and digital sensors have allowed for the collection and aggregation of data barely possible to imagine to anyone in the instrumentation scene even sixty years ago. Before that, things like weather stations, seismometers, level sensors, and basically any other way of gathering real data about the world would have been performed with an analog device recording the information on some sort of spool of paper. This was much more tedious but the one thing going for these types of devices was their aesthetic. [mircemk] is back to bring some of that design inspiration to a digital barometric display.
The barometer is based around an Arduino Arduino Nano and a relatively large I2C display to display the captured data. It also uses a BME 280 pressure sensor board, but the technical details of this project are not the focal point here. Instead, [mircemk] has put his effort in recreating the old analog barographs, which display barometric data on a spool of paper over time, on the I2C display. As the device measures atmospheric pressure, it adds a bar to the graph, displaying the data over time much as the old analog device would have.
We’ve discussed plenty of times around here that old analog meters and instrumentation like this recreation of a VU meter are an excellent way of getting a more antique aesthetic than is typically offered by digital replacements. Adding in a little bit of style to a project like this can go a long way, or you can simply restore the original antique instead.
If you zoom into the screen you are reading this on, you’d see an extremely fine pattern of red, green, and blue emitters, probably LEDs of some kind. This somewhat limits the resolution you can obtain since you have to cram three LEDs into each screen pixel. Engineers at MIT, however, want to do it differently. By growing thin LED films and sandwiching them together, they can produce 4-micron-wide LEDs that produce the full range of color, with each color part of a vertical stack of LEDs.
To put things in perspective, a standard TV LED is at least 200 microns across. Mini LEDs measure upwards of 100 microns, and micro LEDs are the smallest of all. A key factor for displays is the pitch — the distance from the center of one pixel to the center of the next. For example, the 44mm version of the Apple Watch has a pitch of around 77 microns. A Samsung Galaxy 10 is just over 46 microns. This is important because it sets the minimum size for a high-resolution screen, especially if you are building large screens (such as when you build custom video walls (see the video below for more about that).
Editing video tends to involve a lot of keyboard shortcuts, and while this might be fine for the occasional edit, those who regularly deal with video often reach for a macro pad to streamline their workflow. There are plenty of macro keyboards available specifically meant to meet the needs of those who edit a lot of video, but if you want something tailored for your personal workflow you may want to design your own keyboard like this wooden macro pad from [SS4H].
The keyboard itself is built around an STM32 microcontroller, which gives it plenty of power to drive and read the keyboard matrix. It also handles an encoder that is typically included on macro keyboards for video editing, but rather than using a potentiometer-type encoder this one uses a magnetic rotary encoder for accuracy and reliability. There’s a display built into the keyboard as well with its own on-board microcontroller that needs to be programmed separately, but with everything assembled it looks like a professional offering.
[SS4H] built a prototype using 3D printed parts, but for the final version he created one with a wooden case and laser etched keys to add a bit of uniqueness to the build. He also open-sourced all of the PCB schematics and other files needed to recreate this build so anyone can make it if they’d like. It’s not the only macro keyboard we’ve seen before, either, so if you’re looking for something even more esoteric take a look at this keyboard designed to be operated by foot.
Anybody who has ever seen a video wall (and who hasn’t?) will be familiar with the idea of making large-scale illuminated images from individual coloured lights. But how many of us have gone the extra mile and fitted such a display in our own homes? [vcch] has done just that with his Deluxe Smart Curtain that can be controlled with a phone or laptop.
The display itself is made up of a series of Neopixel strips, hung in vertical lines in front of the window. There is a wide gap between each strip, lending a ghostly translucent look to the images and allowing the primary purpose of the window to remain intact.
The brains of the system are hosted on a low-cost M5stack atom ESP32 device. The data lines for the LEDs are wired in a zig-zag up and down pattern from left to right, which the driver software maps to the rectangular images. However, the 5V power is applied to the strips in parallel to avoid voltage drops along the chain.
If you’d like to build your own smart curtain, Arduino sketch files and PHP for the mobile interface are included on the project page. Be sure to check out the brief video of what the neighbors will enjoy at night after the break.
He’s not given us the details of the control circuit he’s used, but in a sense that matters little. We think any Hackaday reader who knows one end of a soldering iron from the other should be able to produce a small DC current from a DAC to drive a meter, and we don’t think the software to make random readings would trouble many of you either.
Getting DOOM to run on a computer it was never meant to run on is a fun trope in the world of esoteric retro computers. By now we’ve seen it run on everything from old NES systems to microwaves, treadmills, and basically anything with a computer inside of it. What we don’t often see are the displays themselves being set up specifically to run the classic shooter. This build might run the game itself on ordinary hardware, but the impressive part is that it’s able to be displayed on this seven-segment display.
This build makes extensive use of multiplexers to drive enough seven-segment displays to use as a passable screen. There are 1152 seven segment digits arranged in a 48 by 24 array, powered by a network of daisy-chained MAX7219 chips. A Python script running on a Raspberry Pi correlates actual image data with the digit to be displayed on each of the segments, and the Raspberry Pi sends all of that information out to the screen. The final result is a display that’s fast enough and accurate enough to play DOOM in a truly unique way.
There is much more information available about this project on their project page, and they have made everything open source for those who wish to follow along as well. The project includes more than just the ability to play DOOM, too. There’s a built-in video player and a few arcade programs programmed specifically to make use of this display. Perhaps one day we will also see something like this ported to sixteen-segment displays instead of the more common seven-segment.
The protocol the display uses was reverse-engineered by prompting the display to update via RF and monitoring the signals sent to between microcontrollers on the display’s control board. Once the protocol was understood, one of the microcontrollers could then be removed and replaced with an ESP32 for direct control. Implementing this takes some disassembly and some delicate soldering, but it’s nothing that should scare off an experienced hacker.
With the right code flashed to the ESP32, as available on Github, it’s possible to run the display directly. The hacked code does a great job driving the display, showing crisp lines and clean colors that indicate the e-Paper display is running properly.