That’s what [Dmitry] decided to do after trying to figure out the best way to light his pad. You see, his room is 4 by 4 meters, and WS2812 RGB LED strips happen to come in 4 meter lengths… Coincidence? We think not.
The problem with using 16 meters of LED strips is powering them… You see, at 16 meters, you’re looking at about 5V @ 57.6A — and we’re guessing you probably don’t have a 5V 60A power supply handy. Not to mention if you run them in series, the resistance of the system is going to kill your efficiency and the last LEDs probably won’t even work… So [Dmitry] had to break the system up. He has two power supplies feeding the strips from the middle of each pair — that way, he doesn’t have to worry about any voltage drops due to the length of the strips.
War, huh, what is it good for? Absolutely nothing, except as an excuse to build a Raspberry Pi powered sentry turret that will track and fire upon your enemies. That’s what [Matt Desmaris] decided to do, and he has released the full details of his build.
It lacks the polished elegance of most military hardware, but what do you expect of a quick and dirty hack? It’s not shiny or ominous, but it has that killer motion-tracking feature. [Matt] is using OpenCV to detect movement from a USB webcam, two servos to pan and tilt the camera and gun and a small relay to pull the trigger. Manual control over the Interwebs is also available.
We’ve seen lots of similar builds using weaponry such as rubber bands and Nerf guns, but this one is a great start if you are interested in seeing how you can tie together tools like OpenCV and servos to create a camera that actively tracks movement.
The BBC Microcomputer System (or BBC Micro) was an innovative machine back in the early 1980’s. One feature that impressed reviewers was a “tube” interface that allowed the machine to become an I/O processor for an additional CPU. When the onboard 6502 became too slow, it could become a slave to a Z-80 or even an ARM processor. The bus was actually useful for any high-speed device, but its purpose was to add new processors, a feature Byte magazine called “innovative.”
[Hoglet67] has released a very interesting set of FPGA designs that allows a small board sporting a Xilinx Spartan 3 to add a 6502, a Z80, a 6809, or a PDP/11 to a BBC Micro via the tube interface. There’s something satisfying about a classic computer acting as an I/O slave to a fairly modern FPGA that implements an even older PDP/11.
The video trail effect is nothing new: it was first used in music videos like “Blame it on the boogie” from the Jackson 5 in 1978. Now, [Antonio Ospite] has put together a nice article that shows the basics of using OpenCV to create this effect in live video. He used the open source video processing package OpenCV for this, creating the effect with a short script. It can run in multiple ways, creating video trail effects, or “catch-up”trails (where the trail reverses into a final frame).
This provides an interesting example of how these video effects have become so much easier to create. The Jackson 5 video was created using a Scanimate and Quantel Paintbox system that was as big as a closet and cost hundreds of thousands of dollars. Now, you can create these effects with free software and a cheap PC. Now you just need to figure out what in our modern world looks awesome with this throwback effect.
The stargate in 2001 is that long, trippy bit where our protagonist Dave “I’m sorry Dave” Bowman gets pulled through space and time into some kind of alternate universe and is reborn as the star child. (Right, the plot got a little bit bizarre.) But the stargate sequence, along with the rest of the visual effects for the film, won them an Academy Award.
Other examples of slit scan animations you’ll recognize include the opening credits for Doctor Who and the warp-drive effect in Star Trek: TNG.
On Thursday The Guardian published information linking Samsung to the current Volkswagen emissions fiasco. Samsung is accused of installing a ‘defeat device’ on some televisions that uses less energy during official testing conditions than would be found during real-world use.
“The apparent discrepancy between real-world and test performance of the TVs is reminiscent of the VW scandal that originated in the US last week,” wrote [Arthur Nelson] of The Guardian. This report was based on an unpublished lab test by the research group ComplianTV which found discrepancies between real-world and test performance when measuring power consumption. According to ComplianTV, this is due to the ‘motion lighting’ setting included in some Samsung TVs. Samsung vehemently denies this ‘motion lighting’ saying that it is not a method of cheating the consumption tests.
Not one to let a good controversy go to waste, the BBC reports a Samsung TV will reduce its power draw shortly after the start of the test. A graph of the power draw of a TV – not explicitly a Samsung television – demonstrating this functionality was found in a PDF of a ComplianTV workshop from last year labeled as, “Typical results recognized during testing” with a decrease in power consumption being a recognized behavior when the appropriate test video was found.
This is not the first time ComplianTV tested a Samsung TV equipped with a ‘motion lighting’ setting. Earlier this year, ComplianTV measured the power consumption of the Samsung UE55H8090 television, and found this TV was compliant with energy regulations. Incredibly, all Samsung TVs listed on the ComplianTV database were found to be compliant with the relevant energy directives.
Samsung’s rebuttal to the Guardian article states the ‘motion lighting’ technology is an ‘out of the box’ feature, active in both the lab and at home. Unlike Volkswagen’s ‘defeat device’ for their diesel engines which is only active during emissions testing, the ‘motion lighting’ technology is active whenever it is enabled in the TV’s settings menu.
Anyone in the US who has shopped for a television in the last four years will have noticed cost-per-year estimates for operating the appliance. This is only an issue if the televisions don’t actually meet that advertised benchmark. Until we see a published study we’re raising our eyebrows at The Guardian, easily one of the most trusted journalistic institutions on the planet, and reserving judgement for Samsung.
The tech is nothing new, but did you know you can make your own graphene using your DVD burner? No seriously — all you need is a light-scribe compatible DVD burner and some graphite oxide.
It’s pretty simple. By placing a thin film on top of a DVD (or any plastic CD shaped disc), and coating it with graphite oxide, you can literally print patterns of graphene using the laser in your DVD burner. By making the shapes shown above, you can introduce an electrolyte and turn the whole thing into a supercapacitor. Albeit, a tiny super capacitor. But — you can print hundreds of them on a DVD in less than an hour.
We’ve covered this before a few times now, but that doesn’t make it any less interesting. We’re still waiting for someone (one of you guys!) to do a project that actually makes use of graphene! Hurry up!
