Trashed Tablet Lives Again Thanks To New Charger IC

November 24, 2020 by 12 Comments

Have you ever pulled a piece of electronics from the trash that looked like nothing was wrong with it, only to take it home and find out it really is dead? Since you’re reading Hackaday, we already know the answer. Trash picking is an honored hacker tradition, and we all know it’s a gamble every time you pull something from the curb. But when the Samsung Galaxy Tab S that [Everett] pulled from the e-waste bin wouldn’t take a charge, he decided to crack it open and see if it was really beyond repair.

The first step was using a USB power meter to see if the tablet was actually pulling any current when plugged in. With just 10 mA on the line, [Everett] knew the device wasn’t even attempting to charge itself. So his next step was to pull the battery and charge it from a bench supply. This got the tablet to wake up, and as far as he could tell, everything else worked as expected. It seemed like the only issue was a blown charging circuit.

Where we’re going, we don’t need ribbon cables.

Now at this point, [Everett] could have just gone online and bought a new motherboard for the tablet and called it a day. But where’s the fun in that? Instead, he wired up a simple charging circuit using a TP4056 IC on a scrap of flexible PCB and mounted it to a square of Kapton tape. He then used 34 AWG magnet wire to connect it between the tablet’s USB port and the battery, bypassing the tablet’s electronics entirely.

The fix worked, but there was a slight problem. Since the TP4056 only goes up to 4.2 V and the battery maxes out at 4.35 V, [Everett] says his hacked charger can only bring the tablet up to 92% capacity according to Android. But considering the alternative, we think its more than a worthy trade-off.

It’s easy to dismiss tablets as largely disposable devices, but this isn’t the first time we’ve seen somebody save one with little more than solder and patience. Of course, what you do with that old tablet once you get it fired back up is another story entirely.

A Motorized Rotary Shop Table From Scratch

November 20, 2020 by 9 Comments

As we’ve seen over the years, it’s possible to bootstrap your own metalworking shop using little more than a pile of scrap steel, a welder, and an angle grinder. With time and dedication, you can build increasingly complex shop tools until you’ve got yourself a nice little post-apocalyptic workshop. It’s the whole idea behind the [Workshop From Scratch] channel, and we never get bored of seeing his incredible backyard engineering.

But eventually, you’ll have built all the basic stuff. What then? Well, as [Workshop From Scratch] shows in a recent video, you can start working on the luxuries. Do you need a motorized table that will let you spin the workpiece and position it an at arbitrary angle? No, probably not. But as the video after the break shows, it’s certainly a handy thing to have around the shop. We especially like how he uses it to quickly and easily produce nearly perfect circular welds.

Note the welded standoffs used to hold on the lid.

From a technical standpoint, this is perhaps one of his more straightforward builds. But at the same time, the attention to detail that he puts into even this “simple” design is phenomenal. Nothing is wasted, and cutoff pieces from one section are often used in imaginative ways elsewhere.

[Workshop From Scratch] is truly a master of working with what you have, and this project is a perfect example. We especially like the tilt mechanism, which uses a massive leadscrew spun by a wiper motor salvaged from an Audi A8 B4. It looks like a fair amount of new hardware went into the control electronics, but even still, we have no doubt that the cost of this build is well below the purchase price of a commercial alternative.

Much like his hydraulic lifting table or motorized plasma cutter, not everyone is going to need something this elaborate in their home shop. But his magnetic vise and mobile drill press cart are far more approachable for the home gamer. Of course even if you don’t follow along and build your own versions of his tools, it’s always worth tuning in just to see him work.

Continue reading “A Motorized Rotary Shop Table From Scratch” →

Portable Ham Antenna Uses SMD Capacitors

November 17, 2020 by 13 Comments

[K6ARK] likes to operate portable, so he puts together very lightweight antennas. One of his latest uses tiny toroids and SMD capacitors to form trap elements. You can see  the construction of it in the video below.

You usually think of toroid winding as something you do when building transmitters or receivers, especially small ones like these. We presume the antenna is best for QRP (low power) operation since the tiny core would saturate pretty quickly at higher power. Exactly how much power you should pass through an FT50-43 core depends on the exact application, but we’ve seen numbers around 5 watts.

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Help, I’m Buried Alive By Tablets!

November 10, 2020 by 50 Comments

It’s fair to say that many Hackaday readers will have a propensity for hoarding electronic or tech junk. Who hasn’t hung on to something because “It might be useful someday”? Spare a thought for [Mike Drew], who in his own words is “buried alive by tablets”. In this case the tablets are Intel-based ones that look as though they ran one of those cut-down Windows versions, and they appear to be rejects from a repair shop processing customer returns that he saved from the dumpster. They are missing their backs, and not all of their screens work, but they amount to a tidy pile of Stuff That’s Too Good To Throw Away.

The exact spec is a 1.4 GHz quad-core Atom with 4 GB of RAM and 32 GB of Flash, and appear from the photos to have HDMI and USB 3 interfaces. Happily they run Linux Mint 20 so they have plenty of potential, but there is only so much that one person can do with them before running out of ideas. He tells us he’s made a Folding@Home cluster, but beyond that he’s open to suggestions. Depending on the age of the commenter no doubt he’ll be exhorted to run Beowulf or mine Bitcoin, but we’d suggest more sensible ideas.

So, what would you do with them? They lack the handy GPIO port of a Raspberry Pi, but with suitable USB peripherals could you use them in any lowish-power distributed node project where the popular SBC would be the usual choice? Perhaps something like WeeWX, or OpenEnergyMonitor. Or how about distributed mesh network nodes, after all there’s an x86 port of LibreMesh. It’s obvious that there’s plenty of potential to be found, so help [Mike] with his problematic bounty in the comments.

Altair Front Panel Tutorials

October 30, 2020 by 43 Comments

If you aren’t old enough to remember when computers had front panels, as [Patrick Jackson] found out after he built a replica Altair 8800, their operation can be a bit inscrutable. After figuring it out he made a pair of videos showing the basics, and then progressing to a program to add two numbers.

Even when the Altair was new, the days of front panels were numbered. Cheap terminals were on their way and MITS soon released a “turnkey” system that didn’t have a front panel. But anyone who had used a minicomputer from the late 1960s or early 1970s really thought you needed a front panel.

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Cluster Deck Packs Four Pis Into One Portable Package

October 22, 2020 by 8 Comments

Parallel computing is a fair complex subject, and something many of us only have limited hands-on experience with. But breaking up tasks into smaller chunks and shuffling them around between different processors, or even entirely different computers, is arguably the future of software development. Looking to get ahead of the game, many people put together their own affordable home clusters to help them learn the ropes.

As part of his work with decentralized cryptocurrency, [Jay Doscher] recently found himself in need of a small research cluster. He determined that the Raspberry Pi 4 would give him the best bang for his buck, so he started work on a small self-contained cluster that could handle four of the single board computers. As we’ve come to expect given his existing body of work, the final result is compact, elegant, and well documented for anyone wishing to follow in his footsteps.

The core unit would make a great desktop cluster.

Outwardly the cluster looks quite a bit like the Mil-Plastic that he developed a few months back, complete with the same ten inch Pimoroni IPS LCD. But the internal design of the 3D printed case has been adjusted to fit four Pis with a unique staggered mounting arrangement that makes a unit considerably more compact than others we’ve seen in the past. In fact, even if you didn’t want to build the whole Cluster Deck as [Jay] calls it, just printing out the “core” itself would be a great way to put together a tidy Pi cluster for your own experimentation.

Thanks to the Power over Ethernet HAT, [Jay] only needed to run a short Ethernet cable between each Pi and the TP-Link five port switch. This largely eliminates the tangle of wires we usually associate with these little Pi clusters, which not only looks a lot cleaner, but makes it easier for the dual Noctua 80 mm to get cool air circulated inside the enclosure. Ultimately, the final product doesn’t really look like a cluster of Raspberry Pis at all. But then, we imagine that was sort of the point.

Of course, a couple of Pis and a network switch is all you really need to play around with parallel computing on everyone’s favorite Linux board. How far you take the concept after that is entirely up to you.

Tesla’s New Tabless Batteries Unlock New Levels Of Performance

October 5, 2020 by 104 Comments

Telsa are one of the world’s biggest purchasers of batteries through their partnerships with manufacturers like Panasonic, LG and CATL. Their endless hunger for more cells is unlikely to be satiated anytime soon, as demand for electric cars and power storage continues to rise.

As announced at their Battery Day keynote, Tesla has been working hard on a broad spectrum of projects to take battery technology to the next level in order to reach their goal of 3 TWh annual production by 2030. One of the most interesting aspects of this was the announcement of Tesla’s new tabless 4680 battery, which will be manufactured by the company itself. Let’s take a look at what makes the 4680 so exciting, and why going tabless is such a big deal. Continue reading “Tesla’s New Tabless Batteries Unlock New Levels Of Performance” →