So much smart-tech is really kind of dumb. Gadgets intended to simplify our lives turn out to complicate them. It often takes too many “clicks” to accomplish simple tasks, and they end up demanding our attention. Our “better mousetraps” end up kludgy messes that are brittle instead of elegant and robust.
The answer might not be faster or newer technology, but a 30-year-old philosophy. Some great thinkers at Xerox PARC, the place where, among other things, the computer mouse was invented, developed principles they called Calm Technology.
With so many students attending class virtually these days, how can you give kids — or adults — some hands on experience with electronics projects? [Ben Finio] says you can by moving your lab to the virtual world using — of all things — Tinkercad. [Ben] should know something about a classroom since he is a lecturer at Cornell.
Of course, you could do this trick with any online simulator, but Tinkercad is nice because it is easy to use, looks real, and doesn’t cost the students a dime. [Ben] mentions there are some scenarios where it is especially useful like large classes or online classes. There are probably some cases where it doesn’t make sense, like teaching RF design, for example. Even then, maybe you just need a different tool.
OpenWRT is one of my absolute favorite projects, but it’s had a rough week. First off, the official OpenWRT forums is carrying a notice that one of the administrator accounts was accessed, and the userlist was downloaded by an unknown malicious actor. That list is known to include email addresses and usernames. It does not appear that password hashes were exposed, but just to be sure, a password expiration has been triggered for all users.
What do hackers do on vacation? What do hackers do whenever they have free time? What do you love to do? That’s right. But how much more fun would it be if you could get together with 5,000 other hackers, share your crazy projects and ideas, eat, drink, dance, swim, and camp out all together for five days, naturally with power and Internet? That’s the idea of the Chaos Communication Camp, and it’s a once-in-four-years highlight of hacker life.
Held not too far outside of Berlin, the Camp draws heavily on hackers from Europe and the UK, but American hackers have been part of the scene since almost the beginning. (And Camp played an important role in the new-wave hackerspaces in the US, but that’s another story.) It’s one thing to meet up with the folks in your local hackerspace and work together on a project or brainstorm the next one, but it’s entirely a different thing when you’re drawing on hackers from all over the world. There was certainly more to see and do at Camp than you could in a month, not to mention in only five days, and this could be overwhelming. But if you dig in, the sense of community that came from shared effort and shared interests was the real take-home. And nearly everything at Camp should have its own article on Hackaday.
How would you survive in a war-torn country, where bombs could potentially fall from the sky with only very short notice? And what if the bomb in question were The Bomb — a nuclear weapon? This concern is thankfully distant for most of us, but it wasn’t always so. Only 75 years ago, bombs were raining down on England, and until much more recently the threat of global thermonuclear war was encouraging school kids to “duck and cover”. How do you protect people in these situations?
The answers, naturally, depend on the conditions at hand. In Britain before the war, money was scarce and many houses didn’t have basements or yards that were large enough to build a family-sized bomb shelter in, and they had to improvise. In Cold War America, building bomb shelters ended up as a boon for the swimming pool construction industry. In both cases, bomb shelters proved to be a test of engineering ingenuity and DIY gumption, attempting to save lives in the face of difficult-to-quantify danger from above.
Elliot Williams and Mike Szczys dig through the most interesting hacks from the past week. On this episode we take a look at a portable power bank build that defies belief. We discuss an all-in-one SDR portable, messing with restaurant pagers, and the software that’s common to both of these pursuits. There’s a hopping robot that is one heck of a PID challenge, and another robot that does nothing but stare you down. We bring it on home with great articles on pianos with floppy disks, and that satellite cluster you should be watching for in the night sky.
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Visitors to the Wizarding World of Harry Potter at Universal Studios are able to cast “spells” by waving special interactive wands in the air. Hackers like us understand that there must be some unknown machinations happening behind the scenes to detect how the wands are moving, but for the kids wielding them, it might as well be real magic. So when his son asked to have a Harry Potter themed birthday party, [Adam Thole] decided to try recreating the system used at Universal Studios in his own home.
Components used in the IR streaming camera
The basic idea is that each wand has a reflector in the tip, which coupled with strong IR illumination makes them glow on camera. This allows for easy gesture recognition using computer vision techniques, all without any active components in the wand itself.
[Adam] notes that you can actually buy the official interactive wands from the Universal Studios online store, and they’d even work with his system, but at $50 USD each they were too expensive to distribute to the guests at the birthday party. His solution was to simply 3D print the wands and put a bit of white prismatic reflective tape on the ends.
With the wands out of the way, he turned his attention to the IR imaging side of the system. His final design is a very impressive 3D printed unit which includes four IR illuminators, a Raspberry Pi Zero with the NoIR camera module. [Adam] notes that his software setup specifically locks the camera at 41 FPS, as that triggers it to use a reduced field of view by essentially “zooming in” on the image. If you don’t request a FPS higher than 40, the camera will deliver a wider image which didn’t have any advantage in this particular project.
The last part of the project was taking the video stream from his IR camera and processing it to detect the bright glow of a wand’s tip. For each frame of the video the background is first removed and then any remaining pixel that doesn’t exceed a set brightness level if ignored. The end result is an isolated point of light representing the tip of the wand, which can be fed into Open CV’s optical flow function to show [Adam] what shape the user was trying to make. From there, his software just needs to match the shape with one of the stock “spells”, and execute the appropriate function (such as changing the color of the lights in the room) with Home Assistant.
Overall, it’s an exceptionally well designed system considering the goal was simply to entertain a group of children for a few hours. We almost feel bad for the other parents in the neighborhood; it’s going to take more than a piñata to impress these kids after [Adam] had them conjuring the Dark Arts at his son’s party.
