A Look Back At Google’s 2015 Chromecast

December 12, 2024 by Maya Posch 15 Comments

Google’s Chromecast was first released in 2013, with a more sophisticated follow-up in 2015, which saw itself joined by the Chromecast Audio dongle. The device went through an additional two hardware generations before the entire line of products was discontinued earlier this year in favor of Google TV.

Marvell's Armada 88DE3006 dual-core Cortex-A7 powers the second-generation ChromeCast. (Credit: Brian Dipert, EDN) — Marvell’s Armada 88DE3006 dual-core Cortex-A7 powers the second-generation Chromecast. (Credit: Brian Dipert, EDN)

In addition to collecting each generation of Chromecast, [Brian Dipert] over at EDN looked back on this second-generation dongle from 2015 while also digging into the guts of a well-used example that got picked up used.

While not having any of the fascinating legacy features of the 2nd-generation Ultra in his collection that came with the Stadia gaming controller, it defines basically everything that Chromecast dongles were about: a simple dongle with a HDMI & USB connector that you plugged into a display that you wanted to show streaming content on. The teardown is mostly similar to the 2015-era teardown by iFixit, who incidentally decided not to assign any repairability score, for obvious reasons.

Most interesting about this second-generation Chromecast is that the hardware supported Bluetooth, but that this wasn’t enabled until a few years later, presumably to fix the wonky new device setup procedure that would be replaced with a new procedure via the Google Home app.

While Google’s attention has moved on to newer devices, the Chromecast isn’t dead — the dongles in the wild still work, and the protocol is supported by Google TV and many ‘smart’ appliances including TVs and multimedia receivers.

Danger-Klipper Fork Renamed To Kalico

December 11, 2024 by Maya Posch 5 Comments

Hobbyist 3D printers have traditionally run the open source Marlin and later Klipper firmware, but as some hobbyists push their printers to the limits, more capable and less conservative firmware was needed. This is why the aptly named ‘Danger-Klipper’ fork of the Klipper firmware comes with the motto ‘I should be able to light my printer on fire’. Because the goal of Danger-Klipper wasn’t literally to light printers on fire (barring unfortunate accidents), the project has now been renamed to Kalico by the developers, after the pirate Calico Jack to maintain the nautical theming.

The Kalico project logo.

Not only does the project get a new name, but also a cute new pirate-themed calico cat logo. Beyond these changes not much else is different, though the documentation is obviously now also at a new domain. As a Klipper fork just about any printer that can run Klipper should be able to run Kalico, though the focus is on Raspberry Pi 2, 3 or 4. The FAQ has some more details on what Kalico can run on. Obviously, Kalico makes for a great option if you are building your own customized 3D printer (or similar), and will support the typical web UIs like Fluidd, OctoPrint, etc.

For some of the differences between Klipper and Kalico, the ‘Danger Features’ section of the documentation provides an impression. Suffice it to say that Kalico is not the kind of firmware to hold your hand or provide guiderails, making it an option for advanced users for whom breaking things while pushing boundaries is just part of the hobby.

Thanks to [Vinny] for the tip.

Retrotechtacular: 1980s Restoration Of San Francisco’s Cable Car System

December 11, 2024 by Maya Posch 43 Comments

The cable car system of San Francisco is the last manually operated cable car system in the world, with three of the original twenty-three lines still operating today. With these systems being installed between 1873 and 1890, they were due major maintenance and upgrades by the time the 1980s and with it their 100th year of operation rolled around. This rebuilding and upgrading process was recorded in a documentary by a local SF television station, which makes for some fascinating viewing.

San Francisco cable car making its way through traffic. Early 20th century.

While the cars themselves were fairly straight-forward to restore, and the original grips that’d latch onto the cable didn’t need any changes. But there were upgrades to the lubrication used (originally pine tar), and the powerhouse (the ‘barn’) was completely gutted and rebuilt.

As opposed to a funicular system where the cars are permanently attached to the cable, a cable car system features a constantly moving cable that the cars can grip onto at will, with most of the wear and tear on the grip dies. Despite researchers at San Francisco State University (SFSU) investigating alternatives, the original metal grip dies were left in place, despite their 4-day replacement schedule.

Ultimately, the rails and related guides were all ripped out and replaced with new ones, with the rails thermite-welded in place, and the cars largely rebuilt from scratch. Although new technologies were used where available, the goal was to keep the look as close as possible to what it looked at the dawn of the 20th century. While more expensive than demolishing and scrapping the original buildings and rolling stock, this helped to keep the look that has made it a historical symbol when the upgraded system rolled back into action on June 21, 1984.

Decades later, this rebuilt cable car system is still running as smoothly as ever, thanks to these efforts. Although SF’s cable car system is reportedly mostly used by tourists, the technology has seen somewhat of a resurgence. Amidst a number of funicular systems, a true new cable car system can be found in the form of e.g. the MiniMetro system which fills the automated people mover niche.

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The Hovercraft Revolution And Finding The Right Niche For A Technology

December 11, 2024 by Maya Posch 41 Comments

In the world of transportation, some technologies may seem to make everything else appear obsolete, whether it concerns airplanes, magnetic levitation or propelling vehicles and craft over a cushion of air. This too seemed to be the case with hovercraft when they exploded onto the scene in the 1950s and 1960s, seemingly providing the ideal solution for both commercial and military applications. Freed from the hindrances of needing a solid surface to travel upon, or a deep enough body of water to rest in, hovercraft gave all the impressions of combining the advantages of aircraft, ships and wheeled vehicles.

Yet even though for decades massive passenger and car-carrying hovercraft roared across busy waterways like the Channel between England & mainland Europe, they would quietly vanish again, along with their main competition in the form of super fast passenger catamarans. Along the English Channel the construction of the Channel Tunnel was a major factor here, along with economical considerations that meant a return to conventional ferries. Yet even though one might think that the age of hovercraft has ended before it ever truly began, the truth may be that hovercraft merely had to find its right niches after a boisterous youth.

An example of this can be found in a recent BBC article, which covers the British Griffon Hoverwork company, which notes more interest in new hovercraft than ever, as well as the continued military interest, and from rescue workers.

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Flying Drones That Can Walk And Jump Into The Air: An Idea With Legs?

December 10, 2024 by Maya Posch 13 Comments

When we look at how everyone’s favorite flying dinosaurs get around, we can see that although they use their wings a lot too, their legs are at least as important. Even waddling or hopping about somewhat ungainly on legs is more energy efficient than short flights, and taking off from the ground is helped by jumping into the air with a powerful leap from one’s legs. Based on this reasoning, a team of researchers set out to give flying drones their own bird-inspired legs, with their findings published in Nature (preprint on ArXiv).

The prototype RAVEN (Robotic Avian-inspired Vehicle for multiple ENvironments) drone is capable of hopping, walking, jumping onto an obstacle and jumping for take-off. This allows the drone to get into the optimal position for take-off and store energy in its legs to give it a boost when it takes to the skies. As it turned out, having passive & flexible toes here was essential for stability when waddling around, while jumping tests showed that the RAVEN’s legs provided well over 90% of the required take-off speed.

During take-off experiments the drone was able to jump to an altitude of about 0.4 meters, which allows it to clear ground-based obstacles and makes any kind of ‘runway’ unnecessary. Much like with our avian dinosaur friends the laws of physics dictate that there are strong scaling limits, which is why a raven can use this technique, but a swan or similar still requires a bit of runway instead of jumping elegantly into the air for near-vertical take-off. For smaller flying drones this approach would however absolutely seem to have legs.

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Trying To Shatter The World’s Fastest RC Car Record

December 10, 2024 by Maya Posch 18 Comments

The RC car is controlled via an FPV setup. (Credit: Luke Bell, YouTube)

Fresh off a world record for the fastest quadcopter, [Luke Bell] decided to try his luck with something more own to earth, namely trying to tackle the world record for the fastest RC car, with the current record set at 360 km/h. Starting off with a first attempt in what will be a video series, the obvious approach seems to be to get some really powerful electric motors, a streamlined body and a disused runway to send said RC car hurtling along towards that golden medal. Of course, if it was that easy, others would have done it already.

With the quadcopter record of nearly 500 km/h which we covered previously, the challenge was in a way easier, as other than air resistance and accidental lithobraking there are no worries about ground texture, tire wear or boundary layer aerodynamics. In comparison, the RC car has to contend with all of these, with the runway’s rough tarmac surface being just one of the issues, along with making sure that the wheels would hold up to the required rotation speed. For the wheels you got options like foam, hard rubber, etc., all with their own advantages and disadvantages, mostly in terms of grip and reliability.

So far speeds of over 200 km/h are easy enough to do, with foam wheels being the preferred option. To push the RC car to 300 km/h and beyond, a lot more experimentation and trial runs will have to be performed. Pending are changes to the aerodynamic design with features also commonly seen in F1 race cars such as downforce spoilers, diffusers and other tricks which should prevent the RC car from (briefly) becoming an RC airplane.

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Raspberry Pi 500 And The Case Of The Missing M.2 Slot

December 9, 2024 by Maya Posch 78 Comments

Raspberry Pi just dropped the new Raspberry Pi 500, which like its predecessor puts the similarly named SBC into a keyboard. In a detailed review and teardown video, [Jeff Geerling] goes over all the details, and what there is to like and not like about this new product.

The new Raspberry Pi 500 with the new Raspberry Pi Monitor. (Credit: Jeff Geerling)

Most of the changes relative to the RP400 are as expected, with the change to the same BCM2712 SoC as on the Raspberry Pi 5, while doubling the RAM to 8 GB and of course you get the soft power button. As [Jeff] discovers with the teardown, the odd thing is that the RP500 PCB has the footprints for an M.2 slot, as seen on the above image, but none of the components are populated.

Naturally, [Jeff] ordered up some parts off Digikey to populate these footprints, but without luck. After asking Raspberry Pi, he was told that these footprints as well as those for a PoE feature are there for ‘flexibility to reuse the PCB in other contexts’. Sadly, it seems that these unpopulated parts of the board will have to remain just that, with no M.2 NVMe slot option built-in. With the price bump to $90 from the RP400’s $70 you’ll have to do your own math on whether the better SoC and more RAM is worth it.

In addition to the RP500 itself, [Jeff] also looks at the newly launched Raspberry Pi Monitor, a 15.6″ IPS display for $100. This unit comes with built-in speakers and VESA mount, but as [Jeff] notes in his review, using this VESA mount also means that you’re blocking all the ports, so you have to take the monitor off said VESA mount if you want to plug in or out any cables.

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