Hold 3500 Volts Up To Your Eye

August 6, 2019 by Bryan Cockfield 15 Comments

Old military equipment can sometimes be found in places like flea markets and eBay for pennies, often because people don’t always know what they have. While [tsbrownie] knew exactly what he was getting when he ordered this mystery device, we’re not sure we could say the same thing if we stumbled upon it ourselves. What looks like a vacuum tube of some sort turns out to be an infrared sensor from an old submarine periscope that was repurposed as a night vision device. (Video, embedded below.)

Of course, getting a tube like this to work requires high voltage. This one specifically needs 3500V in order to work properly, but this was taken care of with a small circuit housed in a PVC-like enclosure. The enclosure houses the tube in the center, with an eye piece at one end and a camera lens at the other, attached presumably by a 3D-printed mount. The electronics are housed in the “grip” and the whole thing looks like a small sightglass with a handle. Once powered up, the device is able to show a classic green night vision scene.

Old analog equipment like this is pretty rare, as are people with the expertise to find these devices and get them working again in some capacity. This is a great video for anyone with an interest in tubes, old military gear, or even if you already built a more modern night vision system a while back.

Thanks to [Zzp100] for the tip!

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Cat Feeder Adds Metrics To Meow Mix

August 5, 2019 by Kristina Panos 16 Comments

If there’s one thing any cat will work for, it’s food. Usually, this just consists of meowing and/or standing on your chest until you give up the goods. [DynamicallyInvokable] has a beautiful cat, Emma, who meows loudly for food at obscene hours of the morning. As she ages, it’s getting harder and more important to control her weight. Clearly, it was time to build the ultimate automatic cat feeder—one that allows him to get lazy while at the same time getting smart about Emma’s weight.

After a year and a half of work, the feeder is complete. Not only does it deliver the goods several times a day, it sends a heap of data to the cloud about Emma’s eating habits. There’s a scale built into the platform, and another in the food bowl. Together, they provide metrics galore that get automatically uploaded to AWS. Everything is controlled with an ESP32 Arduino, including a rainbow of WS2812s that chases its tail around the base of the feeder. The faster it goes, the closer it is to feeding time.

The best part about this unique feeder is that nearly every piece is 3D printed, including the gears. Be sure to check out the build gallery, where you can watch it come together piece by piece. Oh, and claw your way past the break to see Emma get fed.

Emma doesn’t have to worry about sharing her food. If she did, maybe [DynamicallyInvokable] could use facial recognition to meet the needs of multiple cats.

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Dice Reader Brings Tech To Your Craps Game… Or, Ya Know, D&D

August 4, 2019 by Mike Szczys 5 Comments

There are truisms about dice that you’ve probably already heard: if you have just one of them it’s called a “die”, opposite faces of each die always add up to seven, and those dots that you’re adding together are known as “pips”. But what about the infrared properties of those pips? It turns out they reflect less IR than the white body of the die and that trait can be used to build an automatic die reader.

Great projects have a way of bubbling to the surface. The proof of concept comes from way back in 2009, and while the source blog is now defunct, it’s thankfully been preserved by the Internet Archive. In recreating the project based on that barebones description, [Calvin] reached for a set of five IR transmitter/receiver pairs. Take a close look and you’ll see each transmitter is hidden under its partnered receiver. The light shines up through the receiver and the presence of the pip is detected by measuring how much of it bounces back.

This board is only the sensor portion of the design. A 595 shift register provides the ability to control which IR pair is powered, plus five more signals heading out to the analog pins of an Arduino Uno to monitor how much light is being detected by the receivers. Hey, that’s another interesting fact about dice, you only need to read five different pips to establish the value shown!

We wish there were a demo video showing this in action, but alas we couldn’t find one. We were amused to hear [Calvin] mentioned this was a sorting assignment at University and the team didn’t want to build yet another candy sorter. Look, we love an epic M&M sorter just as much as the next electronic geek, but it’s pretty hard to one-up this dice-based random number generator which rolls 1.3 million times each day.

Driving A Big RC Car On The Ceiling

July 30, 2019 by Lewin Day 6 Comments

RC cars are a great way to have fun hooning around. There’s plenty of laughs to be had racing your friends in the local grocery store carpark, ideally after hours. [Ivan Miranda] wanted to go in a different direction, however – and that direction was up. (Video embedded after the break.)

There are existing toys that can pull off a wall-riding feat, but they’re normally on a fairly small scale. [Ivan] wanted to go big, and so outfitted some seriously powerful brushless fans on to his 1/8th Rattler buggy from Hobbyking. After initial failure, a smaller scale model was successfully built and tested, before it was realised the full-sized build had the propellers on backwards.

With this oversight fixed, the car was able to drive on the ceiling, albeit in the limited space between the roof beams. It was somewhat less viable on the wall, struggling to stay stuck and having issues with suspension flex.

Overall, it’s a great application of mass brushless power to fight gravity – the same principle behind the multirotors we all love so much. [Ivan]’s put the same trick to use for getting around on a skateboard, too. Video after the break.

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Dreamcast Gets A Plug-n-Play Hard Drive Mod

July 29, 2019 by Lewin Day 22 Comments

The Dreamcast was a proud moment for Sega, at least initially, being the first console to launch of a new generation. Unfortunately this didn’t translate into massive sales, and the plug was pulled far earlier than expected. The console retains a dedicated fanbase to this day however, who continue to tinker with the hardware. [DreamcastChannel] is one of them, and put together a nifty plug-and-play hard drive mod.

The mod is based on earlier work, which consisted of manually soldering the 44 lines of an IDE cable on to the main Dreamcast motherboard. This allowed an IDE hard drive to be neatly mounted inside the shell, but [DreamcastChannel] knew it was possible to do better.

Starting from scratch, the GDROM optical drive assembly is gutted, leaving just its metal case and PCB. The IDE cable for the hard disk is then soldered to the pads on the PCB. A 3D printed mount is used to fix the hard drive to the metal case. This allows the entire assembly to slot neatly into the Dreamcast, using the GDROM’s original connector.

It’s a hack that makes putting a hard drive into the Dreamcast neat and tidy. Combined with a hacked BIOS and Dreamshell, it makes playing backup games a breeze. We’ve seen plenty of Dreamcast hacks before, too – the VMU is often a key candidate for attention. Video after the break.

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Familiar Parts Make Interfacing Weather Station Easy

July 27, 2019 by Lewin Day 12 Comments

Hackers love to measure things, and enjoy monitoring the world around them. Weather stations are a big part of this, and many tinkerers have tried to interface such hardware with varying levels of success. [Ray] is one such individual, and was pleasantly surprised when working on a recent project.

Unlike more old-school models, the model [Ray] found himself working on was a modern unit with a significant number of sensors, a WiFi interface, and even a color screen. Reading the manual, [Ray] noted the device used the IP 192.168.4.1, which is commonly used by the ESP8266 when running in AP mode. The hunch proved to be correct, and opening the device revealed an ESP-WROOM-2 running the show.

Now working with familiar parts, it was simple to hook up to the onboard serial port to scope for data. To [Ray]’s delight, the device was outputting all the weather data out over the connection, and in plaintext to boot. The station also featured the ability to connect to Weather Underground, and watching the debug messages during this process helped [Ray] to understand the format of the information.

It’s rare that manufacturers make it so easy, but debug ports can often be a treasure trove of information to the budding hacker. We’ve seen others cracked before, too.

Neopixels Recreate Pinball Color Wheel That Never Was

July 25, 2019 by Dan Maloney 6 Comments

With what pinball aficionados pay for the machines they so lovingly restore, it’s hard to imagine that these devices were once built to a price point. They had to make money, and whatever it took to attract attention and separate the customer from their hard-earned coins was usually included in the design. But only up to a point.

Take the 1967 Williams classic, “Magic City.” As pinball collector [Mark Gibson] explains it, the original design called for a rotating color filter behind a fountain motif in the back-glass, to change the color of the waters in an attractive way. Due to its cost, Williams never implemented the color wheel, so rather than settle for a boring fountain, [Mark] built a virtual color wheel with Neopixels. He went through several prototypes before settling on a pattern with even light distribution and building a PCB. The software is more complex than it might seem; it turns out to require a little color theory to get the transitions to look good, and it also provides a chance for a little razzle-dazzle. He implemented a spiral effect in code, and added a few random white sparkles to the fountain. [Mark] has a few videos of the fountain in action, and it ended up looking quite nice.

We’ve featured [Mark]’s pinball builds before, including his atomic pinball clock, We even celebrated his wizardry in song at one point.