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.
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 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.
If you’re looking to rid your day to day life of dead trees, there’s a good chance you’ve already heard of the reMarkable tablet. The sleek device aims to replace the traditional notebook. To that end, remarkable was designed to mimic the feeling of writing on actual paper as closely as possible. But like so many modern gadgets, it’s unfortunately encumbered by proprietary code with a dash of vendor lock-in. Or at least, it was.
[Davis Remmel] has been hard at work porting Parabola, a completely free and open source GNU/Linux distribution, to the reMarkable. Developers will appreciate the opportunity to audit and modify the OS, but even from an end-user perspective, Parabola greatly opens up what you can do on the device. Before you were limited to a tablet UI and a select number of applications, but with this replacement OS installed, you’ll have a full-blown Linux desktop to play with.
You still won’t be watching videos or gaming on the reMarkable (though technically, you would be able to), but you could certainly use it to read and edit documents the original OS didn’t support. You could even use it for light software development. Since USB serial adapters are supported, microcontroller work isn’t out of the question either. All while reaping the considerable benefits of electronic paper.
The only downside is that the WiFi hardware is not currently supported as it requires proprietary firmware to operate. No word on whether or not [Davis] is willing to make some concession there for users who aren’t quite so strict about their software freedoms.
Less than a decade ago, building a completely custom portable computer was more or less out of the question. Sure you could have cobbled something together with a Gumstix board and the dinky NTSC/PAL screen pulled from a portable DVD player, but it wouldn’t exactly have been a daily driver. But now we have cheap high definition LCD panels, desktop 3D printers, and of course, the Raspberry Pi.
We’ve seen these elements combined into bespoke personal computing devices too many times to count now, but very few of them can compare to the incredible YARH.IO. It’s been designed from the ground up for easy assembly and customization; you don’t have to worry about getting custom PCBs made or tracking down some piece of unobtanium hardware. Everything inside of the 3D printed enclosure is an off-the-shelf module, needing little more than the occasional scrap of protoboard to tie them all together.
One glance at the rugged design of the YARH.IO, and it’s clear this device wasn’t meant to live on a shelf. Whether it’s getting tossed around the workbench or thrown into a bag on the way to a hacker con, the militarized design of this portable is ready for action. Using appropriately strong materials such as PETG and ABS, we have no doubt the enclosure will survive whatever the on-the-go hacker can throw at it.
But what’s arguably the best feature of the YARH.IO also happens to be the least obvious: the modular design of the enclosure allows you to remove the lower keyboard section and use it as a battery powered Linux tablet (albeit a rather chunky one). Whether the keyboard is attached or not, you still have access to the Pi’s expansion header thanks to a clever pass-through.
Like with the Mil-Plastic that [Jay Doscher] released recently, we know these 3D printed kits will never be as strong as the real military gear they’re emulating. But let’s be realistic, none of us keyboard warriors will be taking them into an actual battlefield anytime soon. What’s more important is that their modular construction allows them to be easily modified for whatever the user’s needs might be. With as far as the state-of-the-art in DIY bespoke computing as come in the last decade, we can’t wait to see what the future holds.
Tablets, slates, phones, and fablets, there are no shortage of electronics that take the Star-Trek-ish form factor of a handheld rectangle of glass that connects you to everything. This is the world we live in, but unfortunately it’s not currently a world with many Linux options, and certainly not one that includes modular design concepts. This is what motivated [Timon] to design the Damn Linux Table one, a “Proper Linux Tablet” built around the Nvidia Jetson Nano board.
[Timon] is realistic about the limits of modular design. He readily admits you’re not going to upgrade a graphics card on a mobile device, but when it comes to the peripherals, why not? You might want to choose between micro-USB, USB-C, barrel-jack, or do something completely custom. One hacker’s NFC equipment might be replaced by another’s SDR or LoRa. This tablet design sees a world where connecting PCIe components to your mobile devices is completely doable. The point is to make a base model that works great, but has the potential to be what each different user wants their device to be.
At $129 USD, Apple certainly do sell a very expensive “pencil”. Despite the high cost of entry, [Eric] identified several shortcomings and set about solving them himself with a few choice mods.
The first concern is the excessively slippery surface finish, that could lead to the expensive device being dropped and damaged. [Eric] starts by creating a special tool to help handle the pencil during the refinishing process. He highlights how key this is to getting a good final result, without fingerprints or other flaws ruining the finish. With the manipulator ready, the pencil is then given a wipe down with wax and grease remover prior to a dusting of a translucent spray paint. The finish is poor, however, and [Eric] instead elects to try again with a plastic primer first. A series of tinted clear coats are chased with a urethane clear topcoat for a hardy, grippier surface texture.
The final mod concerns the tip. It’s lathed down in a power drill to give a shape more akin to the ballpoint pens [Eric] is used to sketching with. Additionally, the tip is dyed black with a Sharpie marker and a heat gun, to help it contrast better when sketching on a white screen.
These mods may seem trivial to a casual user, but for a designer who draws for a living, usability is key. The striking orange finish is just a bonus. We don’t see too many stylus mods, but with the increased popularity of tablets, we’re sure to see more down the road. If you’ve got one, be sure to drop us a line! Video after the break.
ePaper is an interesting thing, providing a non-backlit viewing experience that is much more akin to reading a book than staring at a screen. The reMarkable tablet is a device designed around just such a display, and [Davis Remmel] has been hacking away at the platform. His latest work brings full-fat Linux to the fore.
The work builds upon [Davis]’s earlier work, installing a microSD slot in the tablet to make development easier. Getting Linux running required a custom kernel, but once sorted, working with the reMarkable is easy. apt is available for easy software installs, and the tablet is demonstrated using several different pieces of software, like mtPaint and Xournal.
The golden part of all this has been getting automated partial screen refreshes working. ePaper displays take a long time to refresh the whole screen. Being able to do faster partial writes makes for a much faster interface, which is evident when some of the drawing software is demonstrated. Even Doom runs, but remains largely unplayable, sadly – the ePaper is still a long way off hitting 25 fps.
We look forward to seeing where [Davis] takes this project, and how display performance improves with newer reMarkable tablets. With the reMarkable 2 out for pre-order, there could be a step change in display speed on the horizon. We’re betting that there’s big things to come yet for ePaper – 2020 may finally be its year.