Illuminated smart curtain in front of a window, beside a Christmas tree

Smart LED Curtain Brings Sprites To Your Windows

January 14, 2023 by Dave Walker 13 Comments

Mobile interface for LED smart curtain display — A mobile interface is a nice touch

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.

If video walls are your kind of thing, then how about this one that uses Ping Pong Balls as diffusers? Continue reading “Smart LED Curtain Brings Sprites To Your Windows” →

Wall Art With A Moving Coil Or Two

November 5, 2022 by Jenny List 11 Comments

Almost every type of retro indicator technology from a Nixie tube to a flipdot with everything else in between has found itself on these pages in some form of artwork or decoration. It’s pleasing then to see one that hasn’t appeared so much over the years, and particularly at the hands of our colleague [Voja Antonic]. He’s taken a large array of moving-coil panel meters and hooked them up to a microcontroller board that’s triggered by a PIR sensor. Normally the readings are random, but get too close to it and all those needles start moving, making for a very different take on an electronic wall display.

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.

Meanwhile [Voja] has produced so many interesting projects over the years, not least the 2022 Superconference badge. Here’s one from a few years ago.

Play DOOM On Seven-Segment Displays

October 29, 2022 by Bryan Cockfield 12 Comments

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.

Driving Three-Color E-Paper Pricetags With An Arduino

October 28, 2022 by Lewin Day 14 Comments

ePaper pricetags are becoming popular parts in the hacker community as a cheap way into tinkering with the technology. [Aaron Christophel] got his hands on a 4.4″ model with red, black, and white colors, and set about programming an ESP32 to drive the price tag instead.

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.

We’ve seen [Aaron’s] work before in this area, when he hacked simpler two-color e-ink price tags. He’s also gone so far as creating entire wall displays out of salvaged displays, which is quite the sight. Video after the break.

Continue reading “Driving Three-Color E-Paper Pricetags With An Arduino” →

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.

Continue reading “I’ll See Your Seven-Segment Mechanical Display And Raise You To 16 Segments” →

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.

Continue reading “Custom Calculator Brings Us Back To The 70s” →