Your Cat Needs Its Own TV

March 10, 2024 by Kristina Panos 21 Comments

Cats are wonderful creatures to have around, and they provide us with hours of entertainment. So why not do a little something to entertain them in return? That’s exactly what [Becky Stern] did by making a cat TV that shows YouTube videos of birds and other cat-approved content. Not all cats seem to care about TV, but [Becky]’s cat Benchley really gets into it.

As you may have guessed, this is a fairly simple build, consisting largely of a Raspberry Pi, a speaker, and a screen — a 5″ HDMI LCD display to be exact. Seems like a nice size for cats. After getting the cat-puter up and running, [Becky] set about designing a 3D-printed enclosure to turn it into a TV. The first draft looked great in marble-effect filament, but lacked breathing holes for the Pi, so the final version has a nice honeycomb pattern that is too small for curious cat paws to fit through.

What their paws can do is accidentally pause the video via the touch screen, so [Becky] swapped the USB cable for a charge-only to prevent this. Be sure to check out the build video after the break, because there is plenty of cat cuteness to be had. [Benchley] was so into it that he went looking around back for cats and squirrels inside the box.

Would you rather not encourage your cats to lie about the house watching TV all day? Make them play piano for their dinner.

Continue reading “Your Cat Needs Its Own TV” →

Ender 3 Plotter Attachment For Printing Onto Cassettes

March 9, 2024 by Maya Posch 15 Comments

One way to look at FDM 3D printers is as machines that turn filament into three-dimensional objects, but at their core they are much more versatile than that. Since they can move just about any tool around in 3D space, you can also use them for plotter tasks, a fact that [Geoffrey Gao] made use of when he had to write labels for a stack of music tapes. The resulting FS-Plotter project is based around a Creality Ender 3 FDM printer. Standard g-code from PrusaSlicer is used to move a pen around, after the latter has been fitted into a (3D-printed) spring-loaded fixture.

The cassette tape is fitted into its own fixture that is attached to the printer bed to hold it in place, while the writing utensil can move in its spring-loaded fixture to account for some unevenness on the surface it’s writing on. In the linked GitHub project a PrusaSlicer profile is provided that can generate 2D plotter Gcode. Where [Geoffrey] says that this project is very useful to him as a musician is that it enables him to make small runs of tapes with professional printing, without running into extra expenses.

Beyond putting a writing utensil into the holder, it could also be used for light engraving and similar tasks, while still making it possible to switch between the FDM hotend and this plotter attachment as needed. For about $30 in parts, it doesn’t seem like a bad deal to get a small-ish plotter and maybe give that old Ender 3 a second life.

The Insurance Buys The Wheelchair, But Not The App To Run It

March 9, 2024 by Jenny List 35 Comments

The writer Cory Doctorow coined the term enshittification to describe the way that services decline in quality as their users become the product. He was talking about online services when he came up with the word, but the same is very much true when it comes to hardware. Items which once just worked now need apps and online services, with marginal benefit to the user if any. It’s one thing when it’s your soundbar or your washing machine, but thanks to Lemmy user [@win95] from the Netherlands we’ve seen a far more egregious example. People with disabilities are being provided with new powered wheelchairs through their medical insurance, but are then discovering that unaffordable in-app purchases are needed to use their features. Continue reading “The Insurance Buys The Wheelchair, But Not The App To Run It” →

Upgrading PC Cooling With Software

March 9, 2024 by Bryan Cockfield 21 Comments

As computing power increases with each new iteration of processors, actual power consumption tends to increase as well. All that waste heat has to go somewhere, and while plenty of us are content to add fans and heat sinks for a passable air-cooled system there are others who prefer a liquid cooling solution of some sort. [Cal] uses a liquid cooler on his system, but when he upgraded his AMD chip to one with double the number of cores he noticed the cooling fans on the radiator were ramping quickly and often. To solve this problem he turned to Python instead of building a new cooling system.

The reason for the rapid and frequent fan cycling was that the only trigger for the cooling fans available on his particular motherboard is CPU temperature. For an air cooled system this might be fine, but a water cooled system with much more thermal mass should be better able to absorb these quick changes in CPU temperature without constantly adjusting fan speed. Using a python script set up to run as a systemd service, the control loop monitors not only the CPU temperature but also the case temperature and the temperature of the coolant, and then preferentially tries to dump heat from the CPU into the thermal mass of the water cooler before much ramping of cooling fans happens.

An additional improvement here is that the fans can run at a much lower speed, reducing dust in the computer case and also reducing noise compared to before the optimizations. The computer now reportedly runs almost silently unless it has been under load for several minutes. The script is specific to this setup but easily could be modified for other computers using liquid cooling, and using Grafana to monitor the changes can easily be done as [Cal] also demonstrates when calibrating and testing the system. On the other hand, if you prefer a more flashy cooling system as a living room centerpiece, we have you covered there as well.

A vanadium based flow battery made with 3D printed parts

A Vanadium Redox Flow Battery You Can Build

March 9, 2024 by Dave Rowntree 36 Comments

Vanadium flow batteries are an interesting project, with the materials easily obtainable by the DIY hacker. To that effect [Cayrex2] over on YouTube presents their take on a small, self-contained flow battery created with off the shelf parts and a few 3D prints. The video (embedded below) is part 5 of the series, detailing the final construction, charging and discharging processes. The first four parts of the series are part 1, part 2, part 3, and part 4.

The concept of a flow battery is this: rather than storing energy as a chemical change on the electrodes of a cell or in some localised chemical change in an electrolyte layer, flow batteries store energy due to the chemical change of a pair of electrolytes. These are held externally to the cell and connected with a pair of pumps. The capacity of a flow battery depends not upon the electrodes but instead the volume and concentration of the electrolyte, which means, for stationary installations, to increase storage, you need a bigger pair of tanks. There are even 4 MWh containerised flow batteries installed in various locations where the storage of renewable-derived energy needs a buffer to smooth out the power flow. The neat thing about vanadium flow batteries is centred around the versatility of vanadium itself. It can exist in four stable oxidation states so that a flow battery can utilise it for both sides of the reaction cell.

Continue reading “A Vanadium Redox Flow Battery You Can Build” →

Rosie The Robot Runs For Real

March 9, 2024 by Al Williams 3 Comments

On the recent 256th episode of the Hackaday podcast, [Kristina] mentioned her favorite fictional robot was Rosie from The Jetsons. [Robert Zollna] must agree since he built a reimagined Rosie and it even caught the notice of mainstream outlet People magazine.

We didn’t find much information outside of the TikTok video (see below; you can use the Guest button if you don’t have an account). However, there were a few clever ideas here. First, the robot mechanism is actually Rosie’s vacuum cleaner. Like a tail wagging a dog, an off-the-shelf floor vac tows the robot body.

Rosie herself is clearly an office chair base with an artistic body. The head rotates, and the mouth appears to open and close, so there’s apparently a little more electronics inside, but that’s nothing you couldn’t throw together with some RC servos and an ESP32.

Some videos cover the build so you might be able to glean more details, but the bite-sized videos aren’t very descriptive even though they are fun to watch. If you thought folks documenting their projects on YouTube was bad, you’re really gonna love the TikTok generation.

We like the look of Rosie, but as a practical matter, we need our robot vac to be smaller, not larger. However, using these off-the-shelf robots as a quick start for a robotics project is reasonable. Especially if you can pick up one cheap. Not that that’s a new idea. They even make stripped-down units with the intent that you don’t want to use them as cleaners.

Continue reading “Rosie The Robot Runs For Real” →