Pac-Man Ghost Helps With Air Quality Sensing

October 21, 2024 by Bryan Cockfield 13 Comments

In the past, building construction methods generally didn’t worry much about air quality. There were enough gaps around windows, doors, siding, and flooring that a house could naturally “breathe” and do a decent enough job of making sure the occupants didn’t suffocate. Modern buildings, on the other hand, are extremely concerned with efficiency and go to great lengths to ensure that no air leaks in or out. This can be a problem for occupants though and generally requires some sort of mechanical ventilation, but to be on the safe side and keep an eye on it a CO2 sensor like this unique Pac-Man-inspired monitor can be helpful.

Although there are some ways to approximate indoor air quality with inexpensive sensors, [Tobias] decided on a dedicated CO2 sensor for accuracy and effectiveness, despite its relatively large cost of around $30. An ESP32 handles the data from the sensor and then outputs the results to an array of LEDs hidden inside a ghost modeled after the ones from the classic arcade game Pac-Man. There are 17 WS2812B LEDs in total installed on a custom PCB, with everything held together in the custom 3D printed ghost-shaped case. The LEDs change from green to red as the air quality gets worse, although a few preserve the ghost’s white eyes even as the colors change.

For anyone looking to recreate this project and keep an eye on their own air quality, [Tobias] has made everything from the code, the PCB, and the 3D printer files open source, and has used accessible hardware in the build as well. Although the CO2 sensors can indeed be pricey, there are a few less expensive ways of keeping an eye on indoor air quality. Some of these methods attempt to approximate CO2 levels indirectly, but current consensus is that there’s no real substitute for taking this measurement directly if that’s the metric targeted for your own air quality.

Nuclear Tomb Must Survive

October 21, 2024 by Al Williams 121 Comments

It is hard to imagine that much we built today will be used ten years from now, much less in a hundred. It is hard to make things that last through the ages, which is why we are fascinated with things like ancient pyramids in Mexico, Egypt, and China. However, even the oldest Egyptian pyramid is only about 5,000 years old. [Mark Piesing] at the BBC visited a site that is supposed to lock up nuclear waste for 100,000 years.

This particular project is in France, but there are apparently dozens of similar projects around the world. Locating these nuclear tombs is tricky. They need to be in a geologically stable area that won’t contaminate water. They also prefer areas already depleted of resources to lessen the chance someone will be digging nearby in the far future. You also need people to agree to have these facilities in their communities, which is probably the most difficult thing to find.

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Zero To Custom MacroPad In 37 Easy Steps

October 21, 2024 by Dave Rowntree 5 Comments

[Jeremy Weatherford] clearly has a knack for explaining projects well enough for easy reproduction but goes way further than most and has created a four-part YouTube series detailing every step from project inception to the final assembly, covering all aspects of 3D modelling and PCB design for a custom MacroPad design. Many tools are introduced along the way, all of which help reduce complexity and, by extension, the scope for errors. As every beginner hacker knows, early successes breed confidence and make for better and more ambitious projects.

Part 1 covers the project motivation and scope and introduces a keyboard layout editor tool. This tool allows one to take a layout idea and generate a JSON file, which is then used to drive keyboard tools. XYZ to produce a usable KiCAD project. The tool only generates a PCB project and an associated netlist file. No schematic is created; you don’t need one for a simple layout.

Part 2 is a walkthrough of the design process in KiCAD, culminating in ordering the PCB from JLCPCB and assembling the surface-mount parts. This particular design uses a controller based on the Sea-Picro RP2040 module, but there are many options if you have other preferences. [Jeremy] shows what’s possible with the selected suppliers, but you need not follow this step precisely if you have other ideas or want to use someone local.

Part 3 covers exporting the mechanical aspects of the PCB out of KiCAD and into a 3D CAD program, specifically OnShape. [Jeremy] covers some crucial details, such as how to read the mechanical drawing of the keys to work out where to place the top plate. It’s very easy to plough straight in at this stage and make a design which cannot be assembled! The plan is to use a simple laser-cut box with a bottom plate with mounting holes lining up with those on the PCB. A Top plate is created by taking the outline of the PCB and adding a little margin. An array of rectangular cutouts are designed for the keys to protrude, lining up perfectly with where the keys would be when mounted on the PCB below. The sides of the case are formed from laser-cut sections that lock into each other and the laser-cut base—using the laser joint feature-script addon tool from the OnShape community channel. A second feature script addon is used to auto-layout the laser-cut components onto a single sheet. A CAM application called Kiri Moto is used to export for laser cutting and is available on the OnShape store.

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The 1983 Clock Four Decades In The Making

October 21, 2024 by Al Williams 13 Comments

In 1983, a 14-year-old [Will] saw an LED clock in The Sharper Image store. At $250, it stayed in the store. That was a lot of money back then, especially for most teenagers. But [Will] didn’t forget. After high school, he and a friend planned to build one from scratch. They worked out how they would do it and did a little prototyping, but never really finished. Well, they never really finished at the time. Because 33 years later, [Will] decided to finally put it together. Check it out in the video below.

[Will’s] learned a lot since his original design, plus we have tech today that would have seemed like magic in the late 1980s. But he wanted to stay true to the original design, so there’s no microcontroller or smart LEDs. Just binary counters and a lot of LEDs. There’s even a 555 doing duty as a reset timer.

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Strange English Teaching Computer Might Have Been Big In Japan

October 21, 2024 by Al Williams 9 Comments

[Ctrl-Alt-Rees] bought something strange on an auction site: a Japanese Cefucom-21 from 1983. No? Didn’t ring a bell for us either. The legend on the front boldly proclaims: “CCI Multipurpose SLAP Computer,” so maybe it is some kind of computer, but it is definitely strange. For one thing, the “screen” isn’t a screen at all. [Rees] has found that it has something to do with teaching English. You can see the odd beast in the video below.

We don’t know how common these were in Japan, but they appear to be virtually unknown everywhere else. Inside is a Z80 computer based on a Sanyo PHC-25, which is a little better known.

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2024 Supercon: Third Round Of Super Speakers

October 21, 2024 by Elliot Williams 3 Comments

The third and final round of the 2024 Supercon talks announcements brings us to the end, and the full schedule is now up on Hackaday.io.

With Supercon just a couple weeks away, we hope you have your tickets already! Stay tuned tomorrow for a badge reveal.

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Open-Source, 3D Printed Trackpad

October 21, 2024 by Bryan Cockfield 22 Comments

Touchpads, or trackpads, have been around since the 1980s. Today, you can often find them in laptops and notebook computers as pointing devices. With no moving parts, a trackpad are easy to integrate into the body of a portable computer. they’re much smaller than the traditional mouse. Until the advent of multitouch and gestures over the past two decades, though, they were generally poor substitutes for an actual mouse. These days, trackpads have enough features that some users prefer them even on their desktop computers. If you’re that type of person and don’t want to shell out a big pile of money for an Apple, Logitech, or other off-the-shelf trackpad you can always build your own.

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