A True 4K Projector From Scrap EBay Components

June 22, 2020 by 44 Comments

Cinemas all over the world have become no-go zones with COVID-19 around, but watching the latest blockbuster on the small screen at home is simply not the same. You could bring the big screen home, but buying a quality projector is going to set you back a small pile of cash. Fortunately [Matt] from [DIY Perks] has an alternative for us, demonstrating how to build your own true 4K projector with parts bought off eBay, for a fraction of the price.

The core of the projector is a small 4K LCD panel, which is from a modified Sony smartphone. [Matt] disassembled the phone, removed the backlight from the LCD, which leaves it semi-transparent, and mounted it at a right angle to the rest of the phone body. The battery was also replaced with a voltage regulator to simulate a full battery. To create a practical projector, a much brighter backlight is needed. [Matt] used a 100W 10 mm diameter LED for this purpose. The LED needs some serious cooling to prevent it from burning itself out, and a large CPU cooler does the job perfectly. Two Fresnel lenses in series are used to turn the diverging light from the LED into a converging light source to pass through the LCD. An old 135 mm large format camera lens is placed at the focal point of light to act as a projection lens. The entire assembly is mounted on a vertical frame of threaded rods, nuts, and aluminium plates. [Matt] also used these threaded rods with GT2 pulleys to create a simple but effective moving platform for the projection lens that allows the focus of the projected image to be adjusted. The frame is topped off by a 45-degree mirror to project the image against a wall instead of the roof, and the frame is covered with aluminium panels.

The video after the break goes into incredible detail on how projector functions and how to build your own down. It definitely looks like a doable build for most hackers. [Matt] will also be releasing a complete PDF build guide in the next few weeks. Continue reading “A True 4K Projector From Scrap EBay Components” →

Popping The Hood On The Flux Beamo Laser Cutter

June 22, 2020 by 27 Comments

While the K40 has brought affordable laser cutting to the masses, there’s no question that it took a lot of sacrifices to hit that sub-$400 price point. There’s a reason that we’ve seen so many upgrades and improvements made to the base model machine, but for the price it’s hard to complain. That being said, for users who don’t mind spending a bit more money for a more complete out-of-the-box experience, there are other options out there.

One of them is the beamo, from FLUX. [Frank Zhao] recently picked up one of these $1,900 USD laser cutters because he wasn’t thrilled with the compromises made on the K40. Specifically, he really liked the idea of the internal water cooling system. Oddly enough, something about using a garden hose and buckets of water to cool the laser seemed off-putting. Luckily for us, he’s got a technical eye and the free time necessary to do a teardown and objective analysis of his new toy.

The short version of the story is that [Frank] is not only happy with the results he’s getting, but finds the machine to be well designed and built. So if you’re looking for a rant, sorry. But what you will find is a methodical look at each subsystem of the beamo, complete with annotated pictures and the kind of technical details that Hackaday readers crave.

We especially like his attempts to identify parts which might be difficult to source in the future; it looks like the CO2 laser tube might be proprietary, but everything else looks fairly jellybean. That includes the Raspberry Pi 3B that’s running the show, and the off-the-shelf touch screen HDMI display used for the interface. [Frank] did note that FLUX was unwilling to give him the credentials to log into the Pi and poke around, but with direct access to the SD card, it’s not like that will stop anyone who wants to get in.

In a way, laser cutters are in a similar situation today to that desktop 3D printers were in a few years ago. The cheap ones cut so many corners that upgrades and fixes are almost a necessity, and building your own machine is often less expensive than buying a commercial offering with similar specs. While the beamo is still a bit too expensive for the average hobbyist, it’s good to see machines of this caliber are at least coming down out of the 5 figure range.

Voice-Command Chess Board Powered By Alexa

June 22, 2020 by 6 Comments

Talking to computers used to be reserved for Star Trek and those with overactive imaginations. Now, it’s a regular part of daily life. [CodersCafe] decided to put this technology to work in a chess robot, with the help of Amazon’s digital assistant. 

The build relies on an Cartesian motion rig, built out of Lego Technics parts. The end effector is fitted with a magnet , fitted onto the Z-axis screw for engaging and disengaging with the pieces. A Mindstorms EV3 controller is used to run the show, hooked up over Bluetooth to an Amazon Echo. This allows the user to ask Alexa to move the pieces for the white player in natural language – by saying, for example, “move from B1 to C3”.

It’s a build that demonstrates how easy it is to create projects with advanced functionality by lacing together the correct off-the-shelf hardware. Other Cartesian-type motion platforms can make great chess robots, too. Video after the break.

Continue reading “Voice-Command Chess Board Powered By Alexa” →

Hunting Neutrinos In The Antarctic

June 22, 2020 by 31 Comments

Neutrinos are some of the strangest particles we have encountered so far. About 100 billion of them are going through every square centimeter on Earth per second but their interaction rate is so low that they can easily zip through the entire planet. This is how they earned the popular name ‘ghost particle’. Neutrinos are part of many unsolved questions in physics. We still do not know their mass and they might even be there own anti-particles while their siblings could make up the dark matter in our Universe. In addition, they are valuable messengers from the most extreme astrophysical phenomena like supernovae, and supermassive black holes.

The neutrinos on earth have different origins: there are solar neutrinos produced in the fusion processes of our sun, atmospheric neutrinos produced by cosmic rays hitting our atmosphere, manmade reactor neutrinos created in the radioactive decays of nuclear reactors, geoneutrinos which stem from similar processes naturally occurring inside the earth, and astrophysical neutrinos produced outside of our solar system during supernovae and other extreme processes most of which are still unknown. Continue reading “Hunting Neutrinos In The Antarctic” →

Gigatron Hack Chat

June 22, 2020 by 6 Comments

Join us on Wednesday, June 24 at noon Pacific for the Gigatron Hack Chat with Walter Belgers!

There was a time when if you wanted a computer, you had to build it. And not by ordering parts from Amazon and plugging everything together in a case — you had to buy chips, solder or wire-wrap everything, and tinker endlessly. The process was slow, painful, and expensive, but in the end, you had a completely unique machine that you knew inside out because you put every bit of it together.

In some ways, it’s good that those days are gone. Being able to throw a cheap, standardized commodity PC at a problem is incredibly powerful, but that machine will have all the charm of a rubber doorstop and no soul at all. Luckily for those looking to get back a little of the early days of the computer revolution or those that missed them entirely, there are alternatives like the Gigatron. Billed as a “minimalistic retro computer,” the Gigatron is a kit that takes the builder back even further in time than the early computer revolution since it lacks a microprocessor. All the logic of the 8-bit computer is built up from discrete 7400-series TTL chips.

The Gigatron is the brainchild of Marcel van Kervinck and Walter Belgers. Tragically, Marcel recently passed away, but Walter is carrying the Gigatron torch forward and leading a thriving community of TTL-computer aficionados as they extend and enhance what their little home-built machines can do. Walter will stop by the Hack Chat to talk all things Gigatron, and answer your questions about how this improbably popular machine came to be.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 24 at 12:00 PM Pacific time. If time zones have you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
Continue reading “Gigatron Hack Chat” →

Wearable Device For Preventing SUDEP (Sudden Unexpected Death In Epilepsy)

June 22, 2020 by 13 Comments

Epilepsy is a neurological disorder characterized by the occurrence of seizures. Epilepsy can often prevent patients from living a normal life since it’s nearly impossible to predict when a seizure will occur. The unpredictability of the seizures makes performing tasks such as driving extremely dangerous. One of the challenges in treating epilepsy is the condition is still not very well understood.

Neurava, a recent startup company from Purdue University, aims to change this fact. Neurava is developing a neck wearable that “records key biological signals related to epilepsy.” None of the press releases we’ve found so far elaborate on what those biological signals are. Though we have some guesses of our own, we’ll leave it to the Hackaday community to speculate for the time being. One of the major hurdles in using biological signals to treat conditions like epilepsy both lies in the accuracy of the measurement itself in addition to how well the measurement correlates to the underlying condition. From the looks of it, Neurava has been working on this technology for a long time and are certainly more aware of these challenges than we are.

Neurava’s wearable includes a few other functionalities we’ve come to expect in this era of smart devices such as wireless data transmission to both the physician and patient, physician dashboard to monitor the patient’s progress over extended periods of time, and in-time alerts in the event a seizure is detected.

Neurava appears to have garnered a bit of publicity in these last few months and are currently securing seed money to help advance their technology. We’ll check in every so often to see how they’re doing.

Teardown: Wonder Bible

June 22, 2020 by 90 Comments

Even the most secular among us can understand why somebody would want to have a digital version of the Bible. If you’re the sort of person who takes solace in reading from the “Good Book”, you’d probably like the ability to do so wherever and whenever possible. But as it so happens, a large number of people who would be interested in a more conveniently transportable version of the Bible may not have the technological wherewithal to operate a Kindle and download a copy.

Which is precisely the idea behind the Wonder Bible, a pocket-sized electronic device that allows the user to listen to the Bible read aloud at the press of a button. Its conservative design, high-contrast LED display, and large buttons makes it easy to operate even by users with limited eyesight or dexterity.

The commercial for the Wonder Bible shows people all of all ages using the device, but it’s not very difficult to read between the lines and see who the gadget is really aimed for. We catch a glimpse of a young businessman tucking a Wonder Bible into the center console of his expensive sports car, but in reality, the scenes of a retiree sitting pensively in her living room are far closer to the mark.

In truth, the functionality of the Wonder Bible could easily be replicated with a smartphone application. It would arguably even be an improvement by most standards. But not everyone is willing or able to go that route, which creates a market for an affordable stand-alone device. Is that market large enough to put a lot of expense and engineering time into the product? Let’s crack open one of these holy rolling personal companions and find out.

Continue reading “Teardown: Wonder Bible” →