The PiShot Is Ready For Your Snaps

The formula for a Raspberry Pi camera is by now a straightforward one: take a Pi and camera module, add a display, buttons, and battery, and you’re done. This doesn’t mean that there’s no scope for more though, and [Irtaza2009] has one in the PiShot. It’s a few months old now but the repository is still being updated.

The 3D printed case follows a compact camera form factor with the screen on the rear, and a cold shoe on top. Inside is a Pi Zero 2 W and a Camera Module 3, with an 18650 cell and battery management/power supply board. The buttons are tactile switches hooked up to GPIOs, and the screen is an ST7789 SPI display.

For software there’s a Python script, which should do the job. We’ve not tested this one, but our experience is that slowness is the Achilles’ heel of Python based Pi cameras. We hope this one has managed to eke out some performance.

An interesting upgrade to this device would be to use an HQ camera module, for a mirror-less compact. It wouldn’t be the first such camera we’ve seen.

The countertop in its natrual habitat: a van.

Cotton-Fiberglass Composite Makes Lightweight RV Countertops

You’ve seen fiber-reinforced-plastic before, no doubt, but perhaps never quite like in this video by [Whitburn Studio]: it’s still got the usual resin, but instead of glass or carbon fibers, he’s using printed Japanese cotton to create strong, lightweight and good looking parts for the interior of his RV– specifically the countertops.

The technique is very similar to the sort of moldless composite work Burt Rutan pioneered in aircraft use. The fiber-reinforced plastic is formed around a positive ‘buck’ that remains inside the final part, adding stiffness and some backing. Unlike Rutan’s designs, which used pure Styrofoam inside, [Whitburn] is using a sandwhich of two layers of thin ply (3.6 mm) with XPS foam in between. Adding plywood means you don’t need many layers of fiber– again, that’s a decorative cotton, here– to get a surface that won’t dent into the styrofoam when you drop a coffee cup on it.

Indeed, with the plywood providing much of the strength, he’s only using a single layer of cotton and a second of fiberglass– though the glass fibers are really there to protect the pretty print from oopsies while sanding, rather than for their mechanical properties, by the sounds of it. Everything is held together with clear epoxy resin, which also fills the weave of the fabrics. Multiple coats of that are required to get the smooth, shiny surface he shows off at the end, but all that sanding and buffing really pays off. That’s also where you have to be really careful to avoid oopsies– go through the cotton and you have to start over.

Aside from the aesthetics, since this is going in a vehicle the weight is an important consideration– the bigger of the two counters he makes, pictured here, weighs in at only 2.4 kg or 5.2 lb including the cutout covering the sink. That’s pretty good all things considered– a lot lighter than a cement countertop, or even one made of DIY resin tiles.

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Building A Bicycle Dropper Seat Post

A recent addition to mountain bikes is the dropper seat post. This invention is in the vein of office swivel chairs, allowing the seat height to be adjusted with a simple handlebar mounted lever. They are rather fascinating inventions ranging in complexity from simple mechanical systems, to electronic monstrosities actuated by Bluetooth. Inspired by the panoply of possibilities, [kane components] set forth to create such a home-built dropper post. 

Inspired by woodworking bar clamps, [kane’s] design utilizing angled plates binding against a rail inside the dropper post. Two pairs of plates sitting at opposite angles resist opposite forces from either the rider sitting on the post, or the return spring. A simple cable actuated cam moves the plates to a nonbinding position when the lever is actuated, and springs return the plates to a binding rest-state. The return is handled by an air spring pressurized against a piston at the bottom of the shaft.

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Teardown Of An Oxford Nanopore MinION DNA Sequencer

Detail of the nanopore chip. (Credit: mikeselectricstuff, YouTube)
Detail of the nanopore chip. (Credit: mikeselectricstuff, YouTube)

For most people the term ‘DNA sequencing’ probably brings to mind large, expensive laboratory equipment in sterile rooms, but over the past decades technological progress really has had its way with it, to the point where it’s now just another small portable device. Something like the Oxford Nanopore MinION unit that [Mike] recently took to bits to ogle at the intricate insides.

This device was trialed in 2014 in a limited release before its commercial release in 2015, with this paper by [Miten Jain] et al. in Genome Biology detailing the workings of this nanopore sequencer. At a mere $2,000 it’s rather remarkable how affordable it is, though this comes with the caveat of the consumables, which are also shown in the video. These come in at a cool £690 per unit, can sequence either RNA or DNA and can be used at most a few times before they need to be replaced.

The main unit is fairly simple, featuring a Xilinx Spartan 6 FPGA and a rather nice slim fan-based cooling solution. For the nanopore unit you get the typical microfluidics system, to guide the deposited fluid containing the genetic material to sequence over the nanopore system. In here we see the actual magic as well, in the form of the high-density pitch ICs on both sides of the PCB inside the consumable sequencer unit.

Although this particular unit got discontinued already, the consumables are still available for it if you are feeling the sequencing itch. Of course, we’re likely to see the costs for DNA and RNA sequencing to keep plummeting, as what were once complex chips get overtaken once again by the progress of technology.

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Linux Fu: Heads Or Tails For VPN

If you’ve done much networking, you surely know the frustration of trying to connect to something, say a Raspberry Pi, that lives behind your consumer router. There are a number of solutions for this, ranging from opening ports on your router along with dynamic DNS. Or, you can operate a VPN server on your network. Modern Linux has a facility called Wireguard that lets you create secure network tunnels very easily, but it is a little difficult to set up. But there are tools like Tailscale that can do most of the work for you. There’s only one problem: Tailscale is sorta-kinda free, but not really. But it turns out, you can build your own Tailscale network, and it is easier than you might imagine.

In all fairness, Tailscale’s free tier is good and recently got even more generous, allowing unlimited nodes and up to six users. That’s plenty for most hackers. However, as we’ve seen before, what they can give they can also take away. Besides, there are some extra services you still have to pay for if you want them, but overall, the free tier is more than enough for most people.

On the other hand, no matter how great the free tier may be, some people don’t want to run things on other people’s hardware. Or you need that 7th user. Or you need paywalled features. No worries. Headscale is a self-hosted service that can do nearly everything the cloud portion of Tailscale does, and if you have a place to host it, you can be your own Tailscale server.

For the client side? That’s the best part. Headscale works seamlessly with the existing Tailscale clients. You simply have to point them to your server instead of the defaults.

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Functional Jumping Pokéball From An Ancient Pokémon World

When playing a game about Pocket Monsters, there’s one thing you can’t avoid using no matter what you do, and that’s a pokeball. Whether it’s a new or old game, you can’t avoid it. Many from different generations or spin-off games have their own fun spin, and that’s what [Kiara] wanted to explore with her custom made replication of an older style of ball.

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The Physics Of Keeping Thermal Power Stations Cool

Recently thermal power stations have been in the news quite a bit, mostly in the context of them being throttled back or shut down due to the river water used to cool them either getting too warm or said river having dropped to a level where it can no longer provide cooling water. Obviously this is a problem, but it helps to understand how we got to this point and what can be done to fix it.

Thermal power stations – also called power plants – come in a wide variety of shapes and sizes, ranging from old-school coal- and gas-fueled power stations to modern nuclear power plants. Something like a concentrated solar power (CSP) station is also a thermal power station, as all of them have a heat source that’s used to generate electricity from, whether that’s a boiler, nuclear reactor core or a big vat of sodium heated up by the Sun via massive mirrors or oil-filled tubes in parabolic throughs.

Except for open-cycle gas turbines (OCGTs) – which are basically jet engines connected to a generator – this thermal energy is then used to generate steam that drives a steam turbine. Once most energy in the steam has been depleted, it has to be condensed back into e.g. water, so that it can be led back to the steam generator. How this condensing step is performed is the question here, with a number of methods available.

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