Raspberry Pi

1258 Articles

Not-Quite-So-Hot Stuff: A Thermal Exam On The Latest Raspberry Pi

December 6, 2019 by 51 Comments

When the Raspberry Pi 4 was first launched, one of its few perceived flaws was that it had a propensity to get extremely hot. It’s evidently something the Pi people take very seriously, so in the months since they have addressed the problem with a set of firmware updates. Now they’ve taken a look at the effect of the fixes in a piece on the Raspberry Pi web site, and it makes for an interesting comparison.

The headline figure is that all updates together remove about a watt of power from the load, a significant quantity for what is still a board that can run from a capable phone charger. Breaking down the separate parts of the updates is where the meat of this story lies though, as we see the individual effects of the various USB, memory, power management and clocking updates. In temperature terms they measure an on-load drop from 72.1 °C to 58.1 °C, which should be a significant improvement for any Pi 4 owner.

There is a debate to be had over in what role a computer such as a Pi should serve. As successive revisions become ever more desktop-like in their capabilities, do they run the risk of abandoning the simplicity of a cheap Linux box as a component that makes us come back for more? It’s a possibility, but one they have very well addressed by developing the Pi Zero. They have also successfully avoided the fate of the Arduino — inexorably tied to its ATmega powered original line despite newer releases. As we have frequently said when reviewing Raspberry Pi competitors, it’s the software support that sets them apart from the herd, something this power-draw story demonstrates admirably.

1984 WeatherMan Pi Shows The Ch-Ch-Ch-Ch-Changes

December 5, 2019 by 8 Comments

When [MisterM]’s MIL gave him a rad 80s portable cassette player, he jumped for joy. Once he figured out the window was exactly the same size as the standard for Raspberry Pi HATs, the possibilities left him reeling. A flurry of ideas later, he settled on a weather display featuring a Pimoroni Unicorn HAT HD.

The 1984 Weatherman Pi pulls data from the Dark Sky API every 1.5 seconds using a Zero W. [MisterM] chose to highlight the current temperature, conditions, and rain probability, though there are heaps of other API goodies still on the table. It shows the current weather conditions as animations, scrolls the temperature, and gives a nice graph of rainfall probability.

Surprisingly, the dazzling display isn’t our favorite part. See those spongy headphones up top? They’re not just for decoration, though they go a long way in helping the cassette player keep its identity. Whenever there’s a change in the weather, they shimmy back and forth on a 9g servo. If the servo were continuous, it might be neat to use them as a weather vane.

Be sure to check out [MisterM]’s comprehensive demo/build video waiting for you on the B-side. We love a good weather display around here, and the more colorful and literal, the better.

Continue reading “1984 WeatherMan Pi Shows The Ch-Ch-Ch-Ch-Changes” →

A Thermal Typewriter For Burning Thoughts

December 5, 2019 by 13 Comments

There’s a certain charm to old technologies that have been supplanted by newer versions. And we’re not just talking about aesthetic nostalgia this time. With older versions of current technology, you are still connected to the underlying process, and that’s a nice feeling.

Part of the typewriter’s charm is in its instant permanence. These days, its so easy to backspace, delete, and otherwise banish thoughts to the void without giving them a fair trial, though it’s nice not to have to pound the keys to make an impression. At the typewriter, your words are immediately committed to paper, for better or worse. You can usually see them pretty well, although maybe not on the current line, and that is good for letting the words flow without judgment.

[Murtaza Tunio] recently used a thermal POS printer in an art project, but it had since grown cold with disuse. Why not turn it into a typewriter? All it took was a Raspberry Pi, a USB keyboard, and an existing Python library for communicating with these parallel printers. Typing is a bit challenging for a few reasons. For one thing, [Murtaza] has to type five lines before the words become visible. The enter key doesn’t come across for some reason, so a different one had to be assigned. On the upside, [Murtaza] can trigger the paper cutter with a keystroke.

Not too hot on thermal printers? You might find this e-ink typewriter refreshing.

Building A Faux Retro Portable Computer

December 1, 2019 by 48 Comments

The modern laptop has its origins in the mid to late 1980s, when shrinking computer hardware and improvements to battery technology finally made mobile computing practical. But before the now iconic clamshell form factor became the standard, there was a market for so-called “portable” computers. These machines often resembled pieces of luggage with keyboards attached, and even at their peak, they were nowhere near as practical as today’s ultra-thin notebook computers. But for the more nostalgic among us, these vintage portables do have a special sort of charm about them.

Looking to recapture some of that magic with modern components, [davedarko] has started working on his own Raspberry Pi portable computer. Just like those machines of yore, his build is designed to be a self-contained computing experience that you can lug around, but not exactly something you’d be popping open on the train. Its extruded aluminum frame holds the display, power supply, and audio hardware, with plenty of room to spare for additional hardware should he decide to pack in a couple hard drives or something more exotic.

The skeletal frame has plenty of room for activities.

We particularly like the 3D printed hinge and lock mechanism he designed that holds the keyboard closed against the front of the frame. Sufficiently old experienced readers will recall this particular feature being a defining characteristic of portables such as the Osborne 1 and Compaq Portable, and it’s great to see it included here. All it needs now is a leather handle on the side to complete the look.

[davedarko] still has some work ahead of him, as ultimately he’d like to completely enclose his computer’s frame with laser cut panels. But the build is certainly progressing nicely, and frankly, it’s already at the point where we’d have no problem pulling it out at the next hackerspace meetup. Between builds like this and the growing collection of cyberdecks we’ve covered recently, it looks as though 1980s design aesthetic is alive and well within the hacker community.

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Raspberry Pi 4 HDMI Is Jamming Its Own WiFi

November 28, 2019 by 76 Comments

Making upgrades to a popular product line might sound like a good idea, but adding bigger/better/faster parts to an existing product can cause unforeseen problems. For example, dropping a more powerful engine in an existing car platform might seem to work at first until people start reporting that the increased torque is bending the frame. In the Raspberry Pi world, it seems that the “upgraded engine” in the Pi 4 is causing the WiFi to stop working under specific circumstances.

[Enrico Zini] noticed this issue and attempted to reproduce exactly what was causing the WiFi to drop out, and after testing various Pi 4 boards, power supplies, operating system version, and a plethora of other variables, the cause was isolated to the screen resolution. Apparently at the 2560×1440 setting using HDMI, the WiFi drops out. While you could think that an SoC might not be able to handle a high resolution, WiFi, and everything else this tiny computer has to do at once. But the actual cause seems to be a little more interesting than a simple system resources issue.

[Mike Walters] on a Twitter post about this issue probed around with a HackRF and discovered a radio frequency issue. It turns out that at this screen resolution, the Pi 4 emits some RF noise which is exactly in the range of WiFi channel 1. It seems that the Pi 4 is acting as a WiFi jammer on itself.

This story is pretty new, so hopefully the Raspberry Pi Foundation is aware of the issue and working on a correction. For now, though, it might be best to run a slightly lower resolution if you’re encountering this problem.

Your Raspberry Pi Cluster Is Not Like This One

November 27, 2019 by 44 Comments

Many readers will have had their first taste of experimentation with cluster computing through the medium of the Raspberry Pi. The diminutive Linux capable boards can easily be hooked up as a group via a network hub, and given the right software become a whole that is greater than the sum of its parts. None of us will however have reached the heights of the Raspberry Pi cluster shown by Oracle at their Oracle OpenWorld conference, a mighty rack packing a cluster of no less than 1060 Pi 3 B+ boards. This machine is touted as a supercomputer and it’s worthy of the name, though perhaps it’s not in the same class as the elite in that field.

Getting that number of individual 3Bs into a human-sized rack is no easy feat, and they have gone for custom 3D-printed racks to hold the boards. PoE would have resulted in too much heat dissipation, so instead they use USB power from an array of large multi-way USB power supplies. A set of switches provide the networking, and a conventional server sits in the middle to provide storage and network booting.

It’s certainly a cool way to wow the crowds at a conference, but we’re unsure whether it delivers the best bang for your supercomputing buck or whether it’s more useful as a large room heater. Meanwhile you can take a look at a few more modest Pi clusters, with unusual operating systems, or slightly more adherence to convention.

Thanks [Frisco] for the tip.

Patrol The Sprawl With This Battle Ready Cyberdeck

November 25, 2019 by 25 Comments

The recent crop of cyberdeck builds are inspired, at least tangentially, by William Gibson’s novel Neuromancer and its subsequent sequels. In the novels, the decks are used as mobile terminals to access the virtual reality of cyberspace. In our world, they’re usually just quasi-retro boxes with Raspberry Pis in them. Artistic license and all that. But the “XMT-19 Cutlass”, a deck built by [CaptNumbNutz], attempts to hew more closely to the source material than most builds we’ve seen.

Of course it won’t be transporting you into the matrix, and ultimately it’s still just a casemod for the Raspberry Pi. But at least it does a fantastic job of fitting the Neuromancer motif. The design is supposed to look like the XMT-19 was a piece of high-tech military hardware that was later co-opted by a cyberspace cowboy operating in the urban megatropolis that Gibson called the Sprawl, with exposed wiring and a visual mish-mash of components.

If you can believe it, the build started out as a locking clipboard of all things. From there, [CaptNumbNutz] started layering on the hand-cut foam greebles and spraying on the WWII inspired color scheme. We especially like the yellow tips on the antennas that invoke the propellers of vintage airplanes, and the serial number stenciled onto the bottom. In a departure from basically every other cyberdeck we’ve seen to date, there appear to be no 3D printed elements on the XMT-19; all the parts are hand made with nothing more than an a sharp knife and a heap of patience.

In terms of the electronics, the whole build has been greatly simplified by the use of a SmartiPi Touch case, which integrates the Pi and touch screen into a single hinged unit that just needed to get bolted to the top of the deck. Plus it gave him an excuse to put a big rainbow ribbon cable on the back of it to reach the Pi’s GPIO ports, which as you know, instantly makes everything look more retro-futuristic.

It might not be packing the raw power of the Intel NUC cyberdeck we covered last year, or have the convincingly vintage look of the VirtuScope, but we’d take the XMT-19 Cutlass into the matrix any day.