When you think of solar energy, you probably think of flat plates on rooftops. A company called WAVJA wants you to think of spheres. The little spheres, ranging from one to four inches across, can convert light into electricity, and the company claims they have 7.5 times the output of traditional solar panels and could later produce even more. Unfortunately, the video below doesn’t have a great deal of detail to back up the claims.
Some scenes in the video are clearly forward-looking. However, the so-called photon energy system appears to be powering a variety of real devices. It’s difficult to assess some of the claims. For example, the video claims 60 times the output of a similar-sized panel. But you’d hardly expect much from a tiny 4-inch solar panel.
A tuned circuit formed by a capacitor and an inductor is a familiar enough circuit, and it’s understood that it will resonate at a particular frequency. As that frequency increases, so the size of the capacitor and inductor decrease, and there comes a point at which they can become the characteristic capacitance and inductance of a transmission line. These tuned circuits can be placed in an enclosure, at which they can be designed for an extremely high Q factor, a measure of quality, and thus a very narrow resonant point. They are frequently used as filters for that reason, and [Fesz] is here with a video explaining some of their operation and configurations.
Some of the mathematics behind RF design can be enough to faze any engineer, but he manages to steer a path away from that rabbit hole and explain cavity filters in a way that’s very accessible. We learn how to look at tuned circuits as transmission lines, and the properties of the various different coupling methods. Above all it reveals that making tuned cavities is within reach.
One of the earliest hobbyist-friendly on-demand 3D printing and fabrication shops, Shapeways, is filing for bankruptcy. As these financial arrangements always go, this may or may not mean the end of the service, but it’s a sure sign that their business wasn’t running as well as you’d hope.
One of the standout features of Shapeways was always that they made metal printing affordable to the home gamer. Whether it was something frivolous like a custom gear-shifter knob, or something all-too functional like a prototype rocket engine, it was neat to have the alternative workflow of iterative design at home and then shipping out for manufacturing.
We don’t want to speculate too much, but we’d be surprised if the rise of similar services in China wasn’t part of the reason for the bankruptcy. The market landscape just isn’t what it was way back in 2013. (Sadly, the video linked in this article isn’t around any more. If anyone can find a copy, post up in the comments?) So while Shapeways may or may not be gone, it’s not like we can’t get metal parts made anymore.
It’s no big secret that a lot of the internet traffic today consists out of automated requests, ranging from innocent bots like search engine indexers to data scraping bots for LLM and similar generative AI companies. With enough customers who are less than amused by this boost in useless traffic, Cloudflare has announced that it’s expanding its blocking feature for the latter category of scrapers. Initially this block was only for ‘poorly behaving’ scrapers, but now it apparently targets all of such bots.
The block seems to be based around a range of characteristics, including the user agent string. According to Cloudflare’s data on its network, over 40% of identified AI bots came from ByteDance (Bytespider), followed by GPTBot at over 35% and ClaudeBot with 11% and a whole gaggle of smaller bots. Assuming that Imperva’s claims of bots taking up over half of today’s internet traffic are somewhat correct, that means that even if these bots follow robots.txt, that is still a lot of bandwidth being drained and the website owner effectively subsidizing the training of some company’s models. Unsurprisingly, Cloudflare notes that many website owners have already taken measures to block these bots in some fashion.
Naturally, not all of these scraper bots are well-behaved. Spoofing the user agent is an obvious way to dodge blocks, but scraper bot activity has many tell-tale signs which Cloudflare uses, as well as statistical data across its global network to compute a ‘bot score‘ for any requests. Although it remains to be seen whether false positives become an issue with Cloudflare’s approach, it’s definitely a sign of the times that more and more website owners are choosing to choke off unwanted, AI-related traffic.
The ongoing story of bogus analytical data being submitted to the public OctoPrint usage statistics has taken a surprising turn with the news that a second plugin was being artificially pushed up the charts. At least this time, the developer of the plugin has admitted to doing the deed personally.
Just to recap, last week OctoPrint creator [Gina Häußge] found that somebody had been generating fictitious OctoPrint usage stats since 2022 in an effort to make the OctoEverywhere plugin appear to be more popular than it actually was. It was a clever attempt, and if it wasn’t for the fact that the fake data was reporting itself to be from a significantly out of date build of OctoPrint, there’s no telling how long it would have continued. When the developers of the plugin were confronted, they claimed it was an overzealous user operating under their own initiative, and denied any knowledge that the stats were being manipulated in their favor.
Presumably it was around this time that Obico creator [Kenneth Jiang] started sweating bullets. It turns out he’d been doing the same thing, for just about as long. When [Gina] contacted him about the suspicious data she was seeing regarding his plugin, he owned up to falsifying the data and published what strikes us as a fairly contrite apology on the Obico blog. While this doesn’t absolve him of making a very poor decision, we respect that he didn’t try to shift the blame elsewhere.
That said, there’s at least one part of his version of events that doesn’t quite pass the sniff test for us. According to [Kenneth], he first wrote the script that generated the fake data back in 2022 because he suspected (correctly, it turns out) that the developers of OctoEverywhere were doing something similar. But after that, he says he didn’t realize the script was still running until [Gina] confronted him about it.
Now admittedly, we’re not professional programmers here at Hackaday. But we’ve written enough code to be suspicious when somebody claims a script they whipped up on a lark was able to run unattended for two years and never once crashed or otherwise bailed out. We won’t even begin to speculate where said script could have been running since 2022 without anyone noticing…
But we won’t dwell on the minutiae here. [Gina] has once again purged the garbage data from the OctoPrint stats, and hopefully things are finally starting to reflect reality. We know she was already angry about the earlier attempts to manipulate the stats, so she’s got to be seething right about now. But as we said before, these unfortunate incidents are ultimately just bumps in the road. We don’t need any stat tracker to know that the community as a whole greatly appreciates the incredible work she’s put into OctoPrint.
If you’re designing a universal port, you will be expected to provide power. This was a lesson learned in the times of LPT and COM ports, where factory-made peripherals and DIY boards alike had to pull peculiar tricks to get a few milliamps, often tapping data lines. Do it wrong, and a port will burn up – in the best case, it’ll be your port, in worst case, ports of a number of your customers.
Want a single-cable device on a COM port? You might end up doing something like this.
Having a dedicated power rail on your connector simply solves this problem. We might’ve never gotten DB-11 and DB-27, but we did eventually get USB, with one of its four pins dedicated to a 5 V power rail. I vividly remember seeing my first USB port, on the side of a Thinkpad 390E that my dad bought in 2000s – I was eight years old at the time. It was merely USB 1.0, and yet, while I never got to properly make use of that port, it definitely marked the beginning of my USB adventures.
About six years later, I was sitting at my desk, trying to build a USB docking station for my EEE PC, as I was hoping, with tons of peripherals inside. Shorting out the USB port due to faulty connections or too many devices connected at once was a regular occurrence; thankfully, the laptop persevered as much as I did. Trying to do some research, one thing I kept stumbling upon was the 500 mA limit. That didn’t really help, since none of the devices I used even attempted to indicate their power consumption on the package – you would get a USB hub saying “100 mA” or a mouse saying “500 mA” with nary an elaboration.
Fifteen more years have passed, and I am here, having gone through hundreds of laptop schematics, investigated and learned from design decisions, harvested laptops for both parts and even ICs on their motherboards, designed and built laptop mods, nowadays I’m even designing my own laptop motherboards! If you ever read about the 500 mA limit and thought of it as a constraint for your project, worry not – it’s not as cut and dried as the specification might have you believe. Continue reading “USB And The Myth Of 500 Milliamps”→
