Crawling a Dungeon, 64 Pixels at a Time

The trend in video games is toward not being able to differentiate them from live-action theatrical releases, and games studios are getting hard to tell from movie studios. But quality graphics don’t always translate into quality gameplay, and a lot can be accomplished with minimalist graphics. Turn the clock back a few decades and think about the quarters sucked up by classics like Pac-Man, Space Invaders, and even Pong if you have any doubts about that.

But even Pong had more than 64 pixels to work with, which is why this dungeon-crawler game on an 8×8 RGB matrix is so intriguing. You might think [Stolistic]’s game would be as simple as possible but think again. The video below shows it in action, and while new users will need a little help figuring out what the various colors mean, the game is remarkably engaging. The structure of the dungeon is random with multiple levels to unlock via the contents of power-up chests, and there are mobs to battle in a zoomed-in display. The game runs on an Arduino Uno and the matrix is driven by a bunch of 74HC595 shift registers.

It’s fun to see what can be accomplished with as little as possible. Looking for more low-res goodness? Check out this minimalist animated display, or a Geiger counter with a matrix display.

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Printed Circuits In The Palm Of Your Hand

If you’ve ever wanted to more fully integrate yourself with technology, you might have to thank a team of researchers — led by [Michael McAlpine] — at the University of Minnesota in the near future. They’ve developed a technique that allows circuits to be printed directly onto your skin, with the team arguing — once the low-cost printer is modified for compact portability — it would be ideal for ‘on-the-fly’ circuit needs.

“But the hand isn’t exactly a stable print bed,” you say. We hear you, and the team is actually one step ahead — the printer can compensate for subtle movements during the printing process by tracking markers placed on the hand. The ‘filament’ is made from silver flakes — akin to conductive ink — which prints and cures at room temperatures, and can be either peeled or washed off. We should hope so, as it’s meant to be layered on human skin.

Speaking of which, it can also print cells!

It’s only been tested on a mouse so far, but the same technology that allows the printer to accurately track the hand means that it could use bio-ink to directly add cells to a wound or some other epidermal affliction to help speed the healing process.

For the circuits, though, you’ll still need the other circuit components and a compact means to power them — to say nothing about the fact that if the circuit is water-soluble, then a little perspiration would cause the ink to run. We’re excited to see where this tech goes!

[Thanks for the tip, Qes!]

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LoRa System Commands Drones From A Distance

LoRa has been making quite a stir in hacker circles over the past couple of years, as it offers a fascinating combination of long range, low power, and low cost. It does this by using spread spectrum techniques on unlicensed frequency bands, meaning it can send data a surprising distance and that you don’t need a radio license to use it. It is mainly used for Internet of Things things, but [Paweł Spychalski] has other ideas: he’s building a system to use it to control a quadcopter drone over distances of 5 kilometers or more. That’s an ambitious aim, considering that the parts he is using cost only a few bucks.

He’s using an off-brand Adafruit Feather LoRa board and a couple of home-made antennas with his own software that takes the data from the Taranis control port of the RC controller, encodes it and chirps it out over the LoRa radio. At the other end, a similar radio receives and decodes the data, feeding it out to the drone.

This is definitely still a work in progress, but he has got it working, flying his drone over the link, keeping control of it out to several hundred meters. At the moment, he can’t go much further as it seems that his LoRa radio is being overwhelmed by the video link on the drone, but he is working on changing the frequency spread & hopping and using a better antenna to provide longer range. We’ve seen some interesting stuff from [Pawel] before, like his DIY telemetry system, so this project is worth keeping an eye on if you are a drone fan.

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Low-Cost Eye Tracking with Webcams and Open-Source Software

“What are you looking at?” Said the wrong way, those can be fighting words. But in fields as diverse as psychological research and user experience testing, knowing what people are looking at in real-time can be invaluable. Eye-tracking software does this, but generally at a cost that keeps it out of the hands of the home gamer.

Or it used to. With hacked $20 webcams, this open source eye tracker will let you watch how someone is processing what they see. But [John Evans]’ Hackaday Prize entry is more than that. Most of the detail is in the video below, a good chunk of which [John] uses to extol the virtues of the camera he uses for his eye tracker, a Logitech C270. And rightly so — the cheap and easily sourced camera has remarkable macro capabilities right out of the box, a key feature for a camera that’s going to be trained on an eyeball a few millimeters away. Still, [John] provides STL files for mounts that snap to the torn-down camera PCB, in case other focal lengths are needed.

The meat of the project is his Jevons Camera Viewer, an app he wrote to control and view two cameras at once. Originally for a pick and place, the software can be used to coordinate the views of two goggle-mounted cameras, one looking out and one focused on the user’s eye. Reflections from the camera LED are picked up and used to judge the angle of the eye, with an overlay applied to the other camera’s view to show where the user is looking. It seems quite accurate, and plenty fast to boot.

We think this is a great project, like so many others in the first round of the 2018 Hackaday Prize. Can you think of an awesome project based on eye tracking? Here’s your chance to get going on the cheap.

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Fail Of The Week: Never Assume All Crystals Are Born Equal

You should be used to our posting the hacks that didn’t quite go according to plan under our Fail Of The Week heading, things that should have worked, but due to unexpected factors, didn’t. They are the fault, if that’s not too strong a term, of the person making whatever the project is, and we feature them not in a spirit of mockery but one of commiseration and enlightenment.

This FOTW is a little different, because it reveals itself to have nothing to do with its originator. [Grogster] was using the widely-available HC-12 serial wireless modules, or clones or even possibly fakes thereof, and found that the modules would not talk to each other. Closer inspection found that the modules with the lack of intercommunication came from different batches, and possibly different manufacturers. Their circuits and components appeared identical, so what could possibly be up?

The problem was traced to the two batches of modules having different frequencies, one being 37 kHz ahead of the other. This was in turn traced to the crystal on board the off-frequency module, the 30 MHz component providing the frequency reference for the Si4463 radio chip was significantly out of spec. The manufacturer had used a cheap source of the component, resulting in modules which would talk to each other but not to the rest of the world’s HC-12s.

If there is a lesson to be extracted from this, it is to be reminded that even when cheap components or modules look as they should, and indeed even when they appear to work as they should, there can still be unexpected ways in which they can let you down. It has given us an interesting opportunity to learn about the HC-12, with its onboard STM8 CPU and one of the always-fascinating Silicon Labs radio chips. If you want to know more about the HC-12 module, we linked to a more in-depth look at it a couple of years ago.

Thanks [Manuka] for the tip.

Hardware Acceleration in the Cloud

Computers are great at a lot of things. However, general-purpose computers can benefit from help on certain tasks, which is why your video card and sound card both have their own specialized hardware to offload the CPU. If Accelize has its way, some of your hardware acceleration will be done in the cloud. Yes, we know. The cloud is the buzzword of the week and we are tired of hearing about it, too. However, this service is a particularly interesting way to add FPGA power to just about any network-connected CPU.

Currently, there are only four accelerators available, including a hardware-assisted random number generator, a GZIP accelerator, an engine for rapidly searching text, and a BMP to JPEG converter. The company claims, for example, that the search engine can find 2500 entries in the 60 GB Wikipedia archive in 6 minutes. They claim a traditional CPU would take over 16 days to do the same task. The BMP to JPEG converter can process faster than required to feed real-time HD video.

The cloud, in this case, is FPGA resources hosted in the Amazon cloud or in the OVH public cloud. They’ll clearly charge for the service at some point using a “coin” system. However, right now they are letting you sign up with nothing more than an e-mail address and crediting your account with 50,000 coins. Apparently, coins are 1,000 for one dollar.

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Simple Home-built Projection Clock Projects Time

There are plenty of cheap projection clocks available, but as [Thomas Pototschnig] points out in this project, where’s the fun in just buying something? He set out to build a cheap projection clock using a small LCD screen, a cheap LED backlight, and a cheap lens. Cheap is the order of the day here, and [Thomas] succeeded admirably, creating a design that can be made with a couple of cheap PCBs, a 3D printer and the other parts mentioned above. He does a nice job of laying out his thinking in this design, showing how he calculated the projection path and made other decisions. His project has room to grow as well: it runs from an Arduino compatible STM32 that could handle many things other than showing the time if you were inclined to expand the project further.

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