Air Hockey Table Embraces DOOM, Retro Gaming

[Chris Downing] recently finished up a major project that spanned some two years and used nearly every skill he possessed. The result? A smart air hockey table with retro-gaming roots. Does it play DOOM? It sure (kind of) does!

Two of the most striking features are the score board (with LCD screen and sound) and the play surface which is densely-populated with RGB LED lighting and capable of some pretty neat tricks. Together, they combine to deliver a few different modes of play, including a DOOM mode.

The first play mode is straight air hockey with automated score tracking and the usual horns and buzzers celebrating goals. The LED array within the table lights up to create the appearance and patterns of a typical hockey rink.

DOOM hockey mode casts one player as Demons and the other as the Doom Slayer, and the LED array comes to life to create a play surface of flickering flames. Screams indicate goals (either Demon screams or Slayer screams, depending on who scores!)

In retrogaming emulation mode, the tabletop mirrors the screen.

Since the whole thing is driven by a Raspberry Pi, the table is given a bit of gaming flexibility with Emulation Mode. This mode allows playing emulated retro games on the scoreboard screen, and as a super neat feature, the screen display is mirrored on the tabletop’s LED array. [Chris] asserts that the effect is imperfect, but to us it looks at least as legible as DOOM on 7-segment displays.

This project is a great example of how complex things can get when one combines so many different types of materials and fabrication methods into a single whole. The blog post has a lot of great photos and details, but check out the video (embedded below) for a demonstration of everything in action. Continue reading “Air Hockey Table Embraces DOOM, Retro Gaming”

This 3D Printable Soldering Air Filter Really Sucks

If you solder (and we know you do), you absolutely need ventilation, even for that lead-free stuff. Fortunately, [tinyboatproductions] has gotten into air quality lately and is here to help you with their snappy 3D printed air-filtering design.

At the heart of this build is a 120 mm notoriously-quiet Noctua fan coupled with a carbon filter. It does what you’d think — position the fan the right way and it sucks the air through the filter, which catches all those nasty particles.

The only problem is that the Noctua uses PWM, so there’s no governing it with a just potentiometer. To get around this, [tinyboatproductions] introduced an Arduino Nano and a buck converter, both of which were admittedly a bit overkill. Now the speed can be controlled with a pot.

Once control of the fan was sorted, [tinyboatproductions] decide to add an OLED display to show the fan speed and power condition, which is a nice touch. Be sure to check out the build video after the break.

If this doesn’t have quite enough features for you, here’s one that’s battery powered.

Continue reading “This 3D Printable Soldering Air Filter Really Sucks”

A Portable Home Air Quality Meter With The ESP32

Around the world, rolling pandemic lockdowns have left many working from home. [kn100] is in just such a predicament, and while spending nearly 24 hour a day in a residential flat, got wondering about air quality. Thus, it was time to build some gear to keep an eye on things!

Grafana may require a database and some work to set up, but the results are to die for.

The build consists of an ESP32 hooked up to a Bosch BME680 air quality sensor. It measures pressure, temperature, humidity and gas resistance, and then with a closed source library, uses this to calculate an “Air Quality Index” as well as estimate CO2 and VOC levels in the air. Data is passed from the ESP32 over MQTT to a Raspberry Pi. This runs Mosquitto for handling the MQTT queries, saving the data in an Influxdb instance. Grafana is then used to query this database and produce attractive graphs of the data.

It’s a build that not only helps keep an eye on things in the flat, but is great practice for building solid Internet of Things devices with top-notch data visualisation. We’ve talked about how to do this before, too – so if you need this capability in your life, there’s no excuse not to get hacking!

Air Hockey Table Is A Breeze To Build

Many of us have considered buying an air hockey table, but are put off by the price. And even if the money is there, those things take up a lot of space. How often are you really going to use it?

This DIY air hockey table is the answer. It’s big enough to be fun, but small and light enough to easily stow away in the off-season. At ~$50, it’s a cheap build, provided you have a vacuum cleaner that can switch to blower mode. The strikers, goals, corner guards, and scoreboard enclosure are all 3D-printed, while the pucks and playfield are laser-cut acrylic. [Technovation] glued acrylic feet to the strikers to help them last longer.

The scoreboard is an Arduino Uno plus an LCD that changes color to match the current winner. Scoring must be entered manually with button presses, but we think it would be fairly easy to detect a puck in the goal with a force or weight sensor or something. For now, the RGB LEDs around the edge are controlled separately with a remote. The ultimate goal is to make the Arduino do it. Shoot past the break and cross-check it out.

Already have a table? Had it so long, no one will play you anymore? Build yourself a robotic opponent.

Continue reading “Air Hockey Table Is A Breeze To Build”

Hot Air Surgery Revives A Cheap Windows Tablet

[Jason Gin] recently wrote in to tell us about his adventures replacing the eMMC storage chip on a cheap Windows tablet, and we have to say, it’s an impressive amount of work for a device which apparently only cost him $15. Surely much better pieces of hardware have been tossed in the trash for less serious failures than what ailed his DigiLand DL801W tablet. We’d love to see the lengths this guy would go to restore something a bit higher up the food chain.

As any good hacker knows, you can’t fix the problem until you understand it. So the first step [Jason] took was to conduct some troubleshooting. The tablet would only boot to the EFI shell, which didn’t do him much good since there was no on-screen keyboard to interact with it. But he had the idea of trying to connect a USB keyboard via an OTG adapter, and sure enough that got him in. Once he was able to enter commands into the EFI shell, he attempted to read from a few different sectors of the eMMC drive, only to get the same nonsense repeating data. So far, not looking good.

But before he fully committed to replacing the eMMC drive, he wanted a second opinion. Using the same USB OTG adapter, he was able to boot the tablet into a Windows 10 environment, and from there got access to some drive diagnostic tools. The software reported that not only was the drive reporting to be half the appropriate size, but that writing to the chip was impossible.

With the fate of the tablet’s Foresee NCEMBS99-16G eMMC chip now confirmed, [Jason] decided it was time to operate. After pulling the tablet apart and masking off the PCB with Kapton tape to protect it from the heat, he slowly went in with his hot air rework station to remove the failed chip. But rather than put another low-end chip in its place, he used this opportunity to replace it with a Samsung KLMBG4GEND-B031. Not only does this chip have twice the capacity of the original, it should be noticeably faster.

With the new Samsung eMMC chip installed, [Jason] put the tablet back together and was able to successfully install Windows 10 onto it. Another piece of tech saved from the big landfill in the sky.

If the casual confidence of this particular repair wasn’t enough of a clue, this isn’t the first time he’s showed some unruly eMMC chips who’s boss.

Retractable Console Allows Wheelchair User To Get Up Close And Personal

[Rhonda] has multiple sclerosis (MS), a disease that limits her ability to walk and use her arms. She and the other residents of The Boston Home, an extended care facility for people with MS and other neuromuscular diseases, rely on their wheelchairs for mobility. [Rhonda]’s chair comes with a control console that swings out of the way to allow her to come up close to tables and counters, but she has problems applying enough force to manually position it.

Sadly, [Rhonda]’s insurance doesn’t cover a commercial solution to her problem. But The Boston Home has a fully equipped shop to extend and enhance residents’ wheelchairs, and they got together with students from MIT’s Principles and Practices of Assistive Technology (PPAT) course to hack a solution that’s not only useful for [Rhonda] but should be generally applicable to other chairs. The students analyzed the problem, measured the forces needed and the clearances required, and built a prototype pantograph mount for the control console. They’ve made the device simple to replicate and kept the BOM as inexpensive as possible since patients are often out-of-pocket for enhancements like these. The video below shows a little about the problem and the solution.

Wheelchair hacks are pretty common, like the 2015 Hackaday Prize-winning Eyedrivomatic. We’ve also covered totally open-source wheelchairs, both manual and electric.

Continue reading “Retractable Console Allows Wheelchair User To Get Up Close And Personal”

A Portable, Accurate, Low-Cost, Open Source Air Particle Counter

If you live in a city with poor air quality you may be aware that particulates are one of the chief contributors to the problem. Tiny particles of soot from combustion, less than 10μm across, hence commonly referred to as PM10. These are hazardous because they can accumulate deep in the lungs, wherein all kinds of nasties can be caused.

There are commercial sensors available to detect and quantify these particles, but they are neither inexpensive nor open source. [Rundong] tells us about a project that aims to change that situation, the MyPart, which is described as a portable, accurate, low-cost, open source air particle counter. There is a GitHub repository for the project as well as a series of Instructables covering the build in detail. It comes from a team of members of the Hybrid Ecologies Lab at UC Berkeley, USA.

Along the way, they provide a fascinating description of how a particulate sensor works. A laser shines at right angles across a photodiode, and is brought to a focal point above it. Any particulates in the air will scatter light in the direction of the photodiode, which can thus detect them. The design of a successful such sensor requires a completely light-proof chamber carefully built to ensure a laminar flow of air past laser and diode. To that end, their chamber has several layers and is machined rather than 3D-printed for internal smoothness.

We’ve covered quite a few environmental sensors over the years here at Hackaday. An open source volatile organic compound (VOC) detector featured last year for example, or this Raspberry Pi-based  system using a commercial gas sensor.