Antique Motherboard Speaks

October 22, 2023 by 18 Comments

[Bits und Bolts] has been restoring an old PC motherboard with the infamous bad electrolytic capacitors. The video of his exploits was interesting enough, but pretty standard stuff. What we found interesting though, was an odd feature of the ASUS Bios called “Post Reporter” that let the motherboard speak error codes and status through the external speaker. (Video, embedded below.) We aren’t sure who wanted that, and since we haven’t seen it around lately, we are guessing the answer was nobody wanted it.

We enjoyed watching the PCB rework. Those large internal ground plane layers do make it hard to unsolder and then solder the caps. That makes the job seem deceptively easy. However, if you want to skip to the exotic BIOS, jump to the 8:20 mark.

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Adobe Scientist Cuts A Dash With LCD Shifting Dress

October 22, 2023 by 63 Comments

Adobe research scientist [Christine Dierk] showed off an interesting new project at the Adobe Max conference: Project Primrose, a dress covered with a series of liquid crystal panels that could react to movement, changing the design of the dress. Now, Adobe has released a paper showing some of the technical details of the process.

The paper is from the User Interface & Software (UIST) conference in 2022, so the examples it uses are older: it discusses a canvas and handbag. The dress uses the same technology, though, draped over a scientist rather than a frame. If you can’t access the version from UIST, [Dierk] has a free version here.

The dress uses Polymer-dispersed Liquid Crystal (PDLC) panels from the wonderfully named Shanghai HO HO Industry Co and is designed for use in windows and doors for privacy. It uses an Indium Tin oxide-coated PET film that is opaque by default but becomes transparent when a voltage difference is applied across the material.

These panels are shaped to a hexagonal shape, then wired together with flexible PCBs in a daisy chain. Interestingly, [Dierk] found that the smaller the panels were made, the lower the voltage was required to trigger them. For their canvas example, they dropped the voltage to a much safer -15V to 15V levels to trigger the two states, which is much safer for a wearable device.

The panels are also not completely transparent when triggered: the paper describes them as having a “soft ivory” look when they are overlaying a reflective material. Greyscales can also be made using Pulse Coded Modulation (PCM) to vary the panel’s transparency. Driving the panels at 3.2KHz, they created 64 shades of grey.

The main controller is a custom PCB with a Teensy 4.1 and a BlueFruit LE SPI module. The power comes from two 14.8V LiPo batteries, with converters to power the chips and switch modules so the Teensy can switch the -15 and +15V levels for the panels directly from each battery.

The array is made from modules, each with four panels connected to a controller PCB, which has several Analog Signal Device (ASD) ADG1414 chips. These receive the signals from the bus with switch registers to switch the panels individually.

Rather cleverly, [Dierk] uses the bus that daisy chains the modules together to deliver both power and the bus signal that controls the panels, using the -15 and +15V levels modulated with a 50Hz square wave to create the bus signal and power the panels at the same time. That’s a neat hack that reduces the complexity of the modules significantly.

The Teensy 4.1 controls the whole system and can use its IMU to sense movement and change the pattern accordingly. You don’t get to see the system’s electronics in the dress video, but they claim that the canvas example took just 0.58 Watts to drive, so the dress probably only needs a few watts.

It is a fascinating build (and a rather cute dress), and has a lot of potential. What would you do with this?

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NASA JPL’s Voyager Team Is Patching Up Both Voyagers’ Firmware

October 22, 2023 by 79 Comments

It’s not every day that you get to update the firmware on a device that was produced in the 1970s, and rarely is said device well beyond the boundaries of our solar system. This is however exactly what the JPL team in charge of the Voyager 1 & 2 missions are facing, as they are in the process of sending fresh firmware patches over to these amazing feats of engineering. These patches should address not only the attitude articulation and control system (AACS) issues that interrupted Voyager 1’s communication with Earth a while ago, but also prevent the thruster propellant inlet tubes from getting clogged up as quickly.

Voyager 2 is the current testbed for these patches, just in case something should go wrong despite months of Earth-based checking, testing and validation. As Voyager 1 is the furthest from Earth, its scientific data is the more valuable, but ideally neither spacecraft should come out worse for wear after this maintenance session.

The AACS fixes are more of an insurance policy, as the original cause of the issue was found to be that the AACS had entered into an incorrect mode, yet without a clear understanding of how this could have happened. With these changes in place, recovery should be much easier. Similarly, the changes to the use of the thrusters are relatively minor, in that they will mostly let the spacecraft drift a bit more out of focus before the thrusters engage, reducing total thruster firings and thus the build-up of material in these inlet tubes.

With these changes the antennae of both spacecraft should remain trimmed firmly towards the blue planet which they left over forty-five years ago, and enable them to hopefully reach that full half century mark before those of us who are still listening have to say our final farewells.

Custom Fume Hood For Safe Electroless Plating

October 22, 2023 by 10 Comments

There are plenty of chemical processes that happen commonly around the house that, if we’re really following safety protocols to the letter, should be done in a fume hood. Most of us will have had that experience with soldering various electronics, especially if we’re not exactly sure where the solder came from or how old it is. For [John]’s electroless plating process, though, he definitely can’t straddle that line and went about building a fume hood to vent some of the more harmful gasses out of a window.

This fume hood is pretty straightforward and doesn’t have a few of the bells and whistles found in commercial offerings, but this process doesn’t really require things like scrubbing or filtering the exhaust air so he opted to omit these pricier and more elaborate options. What it does have, though, is an adjustable-height sash, a small form factor that allows it to easily move around his shop, and a waterproof, spill-collecting area in the bottom. The enclosure is built with plywood, allowing for openings for an air inlet, the exhaust ducting, and a cable pass-through, and then finished with a heavy-duty paint. He also included built-in lighting and when complete, looks indistinguishable from something we might buy from a lab equipment supplier.

While [John] does admit that the exhaust fan isn’t anything special and might need to be replaced more often than if he had gone with one that was corrosion-resistant, he’s decided that the cost of this maintenance doesn’t outweigh the cost of a specialized fan. He also notes it’s not fire- or bomb-proof, but nothing he’s doing is prone to thermal anomalies of that sort. For fume hoods of all sorts, we might also recommend adding some automation to them so they are used any time they’re needed.

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Stage Lighting Hack Keeps La Bohème From Becoming A Dumpster Fire

October 22, 2023 by 20 Comments

With all due respect to the Utah Opera’s production of La bohème, we just couldn’t resist poking a little fun at master electrician [David Smith]’s quick lighting hack for the opera. And who knew an opera from 1896 would need a garbage can fire? Live and learn.

In what appears to be a case of “The show must go on,” [David] was called on to improve an existing fire effect for one scene in the opera, which was reportedly a bit “artificial and distracting.” This is a pretty common problem in live productions of all types; it’s easy to throw light at a problem, but it’s often hard to make it both convincing and unobtrusive. Luckily, he had both the time to come up with something, and a kit full of goodies to make it happen. A balled-up strip of Neopixels provided the light, with an Arduino running some simple code to randomize the intensity and color of the RGBs. [David] stuck with the warm white, red, and green colors, to keep the color temperature about right for a fire, and drove the LEDs with a couple of MOSFETs that he keeps in his kit to fix busted dimmer packs.

The overall effect worked well, but the holes knocked in the side of the greatly abused garbage can let too much light out, making the effect distracting on stage. The remedy was simple: a cylinder of printer paper surrounding the LED tape. The paper not only acted as a diffuser but held the tape in place inside the can. The electrical crew ran two circuits to the can — one to keep the Arduino running throughout the show, and one to power the LED tape. The former made sure the audience didn’t see the microcontroller boot sequence, and the latter gave the electrician a way to control the effect from the dimmer console. The brief video below shows it in action during a rehearsal.

Hats off to [David] and the whole crew for the stagecraft heroics and for getting this thrown together so quickly.

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Atomic Antenna Uses Lasers

October 21, 2023 by 12 Comments

If you think about it, an antenna is nothing more than a radio frequency energy sensor, or — more precisely — a transducer. So, it shouldn’t be a surprise that there could be different ways to sense RF that would work as an antenna. A recent paper in Applied Physics Letters explains an atomic antenna comprised of a rubidium vapor cell.

The interesting thing is that the antenna has no electrical components in the antenna, and can be located far away from the actual receiver. Instead of coax cables, the signal is read with a laser.

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Bluetooth Device Visualizer Reveals Devices In Vicinity

October 21, 2023 by 2 Comments

Have you ever wondered how many Bluetooth devices are floating around you? You could use one of those creepy retail store Bluetooth tracking systems, or set your smartphone to scan. Alternatively, you could use the Bluetooth Devices Visualizer from [Jeremy Geppert].

The device was inspired by [Jeremy’s] trip to Hackaday Supercon 2022. Wanting to build something with LEDs that worked in a badge-like form factor, he set out on whipping up a device to scan and display a readout of Bluetooth devices in the immediate area.

The device is based on an ESP32 microcontroller, which provides the necessary Bluetooth hardware to scan for devices. It then displays the number of devices found using an 8 x 8 array of addressable LEDs. There is also a small OLED display on board for displaying relevant details to the device’s operation. The device neatly fits on a lanyard, and is more of an art project than anything else. It’s no wardriver, and details of devices found are not logged or stored in any way when the device is switched off.

With a variety of operational modes, it’s a fun way to get an idea of just how many Bluetooth devices are really out there these days. If you’ve got your own nifty Bluetooth hacks in the works, don’t hesitate to let us know!