A Raspberry Pi Tablet, With A DSI Screen

March 24, 2021 by Jenny List 36 Comments

Since the Raspberry Pi arrived back in 2012, we’ve seen no end of interesting and creative designs for portable versions of the little computer. They often have problems in interfacing with their screens, either on the very cheap models using the expansion port or on more expensive ones using an HDMI screen with associated controller and cabling. The official Raspberry Pi touchscreen has made life easier with its DSI convector, but as [jrberendt] shows us with this neat little tablet, there are other DSI-based options. This one uses a 5″ DSI touchscreen available through Amazon as well as a Pi UPS board to make a tablet that is both diminutive and self-contained.

Having fooled around ourselves in the world of Pi tablets we like this one for its clean look and a bezel that is little bigger than the screen itself. As is the case with so many Pi tablets though it has to contend with the bulk of a full-sized Model B board on its behind, making it more of a chunky brick than a svelte tablet. The screen has potential though, and we can’t help wondering whether there’s any mileage in pairing it with a much thinner Pi Zero board and a LiPo board for a slimmer alternative.

Probably the nicest Pi tablet we’ve brought you was this one, which managed to remain impressively slim despite its HDMI screen.

Trashed Tablet Lives Again Thanks To New Charger IC

November 24, 2020 by Tom Nardi 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.

Help, I’m Buried Alive By Tablets!

November 10, 2020 by Jenny List 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.

A Free Software OS For The ReMarkable E-Paper Tablet

September 6, 2020 by Tom Nardi 82 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.

We’ve been waiting patiently for the electronic paper revolution to do more than replace paperbacks with Kindles, and devices like the reMarkable seem to be finally moving us in the right direction. Thankfully, projects that aim to bring free and open source software to these devices mean we won’t necessarily have to let Big Brother snoop through our files in the process.

Netbooks: The Form Factor Time Forgot

June 4, 2020 by Lewin Day 172 Comments

Long ago, before smartphones were ubiquitous and children in restaurants were quieted with awful games on iPads, there was a beautiful moment. A moment in which the end user could purchase, at a bargain price, an x86 computer in a compact, portable shell. In 2007, the netbook was born, and took the world by storm – only to suddenly vanish a few years later. What exactly was it that made netbooks so great, and where did they go?

A Beautiful Combination

An Asus EEE PC shown here running Linux. You could run anything on them! Because they were real, full-fat computers. No locked down chipsets or BIOS. Just good, clean, x86 fun.

The first machine to kick off the craze was the Asus EEE PC 701, inspired by the One Laptop Per Child project. Packing a 700Mhz Celeron processor, a small 7″ LCD screen, and a 4 GB SSD, it was available with Linux or Windows XP installed from the factory. With this model, Asus seemed to find a market that Toshiba never quite hit with their Libretto machines a decade earlier. The advent of the wireless network and an ever-more exciting Internet suddenly made a tiny, toteable laptop attractive, whereas previously it would have just been a painful machine to do work on. The name “netbook” was no accident, highlighting the popular use case — a lightweight, portable machine that’s perfect for web browsing and casual tasks.

But the netbook was more than the sum of its parts. Battery life was in excess of 3 hours, and the CPU was a full-fat x86 processor. This wasn’t a machine that required users to run special cut-down software or compromise on usage. Anything you could run on an average, low-spec PC, you could run on this, too. USB and VGA out were available, along with WiFi, so presentations were easy and getting files on and off was a cinch. It bears remembering, too, that back in the Windows XP days, it was easy to share files across a network without clicking through 7 different permissions tabs and typing in your password 19 times.

Continue reading “Netbooks: The Form Factor Time Forgot” →

EPaper Tablet Gets Desktop Linux Install

May 27, 2020 by Lewin Day 34 Comments

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.

Checking In On Relatives Using Old Android Tablets

April 25, 2020 by Erin Pinheiro 15 Comments

With social distancing it can be harder to stay in touch with our relatives, especially those who are elderly and not particularly tech-savvy. Looking for a solution to that end for his own grandmother, [Steve] came up with the idea of using an inexpensive used tablet and a mobile data plan in order to mail her a “video phone” that works out of the box.

This method requires zero button presses in order to pick up a video call.

Since the tablet is configured to use cellular networks rather than WiFi, it requires no setup process at all to the recipient. And with the Android version of Skype, it’s possible to configure it so that calls are automatically picked up and video chat enabled. That way, whoever gets the tablet after it’s prepared doesn’t have to tap a single button on the screen in order to receive a call.

[Steve] has also developed the simple idea into a full-fledged easy-to-follow tutorial so that just about anyone is able to replicate the process for their own loved ones. And if you’re still having any trouble with it, there’s a team of volunteers right on the website who can help you with tech support. Just remember to disinfect whatever device you’re sending, since viruses can typically stick to surfaces like plastic and glass for longer.

Now, if showing up to your relatives as a disembodied video screen doesn’t cut it for you, then you might want to send them something more substantial like this cute little telepresence robot that can drive around on a desk.