Day: September 16, 2019

The Benefits And Pitfalls Of Using PCBs As An Enclosure

September 16, 2019 by 21 Comments

[Mastro Gippo] found himself in a pickle recently, with the development of an enclosure for the Prism electric vehicle charger. The body had been sorted out, but the front cover needed work. It had to be visually appealing, and ideally should provide the user feedback on the charging process. After some thought, [Mastro] decided to explore the possibilities of using a PCB as a part of a commerical product enclosure.

For a variety of reasons, using a specially designed PCB was an attractive solution for the team’s enclosure. Wanting something cost effective, easily customizable, and something that would help with emissions compliance, a PCB seemed like a great idea. With this in mind, [Mastro] prepared a series of prototypes. These feature see-through sections for LEDs to shine through, as well as a capacitive button and gold-plated logo. The fact that the front cover is a PCB makes the integration of the electronic components a cinch.

Before heading into full production, [Mastro] began to question why this technique isn’t used more often. Deciding to research further, [Bunnie Huang] was tapped to provide some advice on the concept. Noting that there can be issues with lead content, as well as the fact that PCBs aren’t often produced with proper regard to aesthetics, there were some pitfalls to the idea. Additionally, ESD testing can be difficult, while the in-built capacitive button would face issues in wet conditions.

None of these are showstoppers however, and [Mastro] has persevered, combining the front cover PCB with an adhesive plastic sheet for added protection. We fully expect that if more manufacturers explore this route, it may be a more viable technique in future. It’s also a great example of knowing when to ask others for help – it’s not the first time we’ve learned from [Bunnie’s] broad experience!

Hams In Space: Gearing Up For The Lunar Gateway

September 16, 2019 by 12 Comments

Humanity had barely taken its first tentative steps into space with primitive satellites when amateur radio operators began planning their first satellites. Barely four years after Sputnik’s brief but momentous launch and against all odds, OSCAR 1 was launched as a secondary payload from an Air Force missile taking a spy satellite into orbit. Like Sputnik, OSCAR 1 didn’t do much, but it was a beginning.

Since then, amateur radio has maintained a more or less continuous presence in space. That first OSCAR has been followed by 103 more, and hams have flown on dozens of missions from the Space Shuttle to the ISS, where pretty much everyone is a licensed amateur. And now, as humans prepare once again to journey into deep space via the stepping stone of the proposed Lunar Gateway, amateur radio is planning on going along for the ride.

Continue reading “Hams In Space: Gearing Up For The Lunar Gateway” →

Over-Engineered Cat Door Makes Purrfect Sense

September 16, 2019 by 21 Comments

On paper, pet doors are pretty great. You don’t have to keep letting the cat in and out, and there should be fewer scratches on the door overall. Unfortunately, your average pet door is indiscriminate, and will let any old creature waltz right in. Well, [Jeremiah] was tired of uninvited critters, so he built a motorized door with a built-in bouncer. Now, only animals with pre-approved BLE tags can get in.

The bouncer is a Raspi 3 running Node-RED, which scans continuously for BLE advertisements from the cats’ collars. [Jeremiah] settled on Tile tags because they’re reliable and cat-proof. The first version used an Arduino and RFID tags for the cats, but they had to get too close to the door to trigger it.

We love [Jeremiah]’s choice of door actuator, a 12V retractable car antenna. [Jeremiah] uses the antenna itself to lift and lower the removable lockout panel that comes with the door. He removed the circuit that retracts the antenna when power is lost, so that power outages don’t become free-for-alls for shelter-seeking animals.

There’s also a nice feature for slow creatures—the door won’t close until 15 seconds after the last BLE ad, so they cats won’t ever have to Indiana Jones it through the opening. Magnetic switches currently limit the door travel at the top and bottom, though [Jeremiah] will eventually replace them with standard switches. Paw at the break until you get a walk-through video.

Cats will be cats, and the ones that go outside will probably rack up a body count. Here’s a cat door that looks for victims clenched between cat jaws and starts a 15-minute lockout period.

Continue reading “Over-Engineered Cat Door Makes Purrfect Sense” →

Upping The Story-Telling Game With Dialog And The Å-Machine

September 16, 2019 by 5 Comments

During the decades since Infocom released their interactive story game Zork to world-wide acclaim for microcomputers, the genre of interactive fiction (IF) is still immensely popular, with a surprising number of modern IF works targeting Infocom’s original Z-Machine runtime for 8-bit micocomputers. We’ve seen a number of improved runtimes and languages for the platform over the years, with [Linus Åkesson]’s Dialog language a newcomer.

Covering the technical details about the language in this thread at IntFiction, the interesting aspect about this language is that while it has a compiler that compiles it to Z-code for the Z-Machine, [Linus] has also implemented a new runtime, called the ‘Å-Machine‘, since ‘Å’ follows ‘Z’ in the alphabet (if you’re Swedish, that is). This runtime should allow for larger stories and other features that make better use of more resources, while still allowing smaller stories to work on old hardware. Unfortunately the only Å-Machine implementation at this point is written in JavaScript, which is not known to work particularly well on Commodore 64 or even Amiga 500 systems.

As for Dialog itself, its documentation provides a detailed overview of the language’s capabilities, which claims to be inspired by both Inform 7 and Prolog. Its goals are to be easy to follow, with a minimal number of language concepts, and high performance. As the documentation notes, many Z-Machine based stories exist today that are unplayable on vintage hardware due to lack of optimization.

We covered Zork and the Z-Machine a while ago in some detail. We think it’s great to see that there’s still so much interest in the platform. Maybe someone will write an Å-Machine implementation for a Commodore or MSX system one of these days to see how it compares to Infocom’s Z-Machine. Here’s to another few decades of the Zork-legacy.