Building Custom Backyard Solar Lights

In this modern age, if you want a truly swish garden that makes your friends sad when they visit, you need good lighting. [technocraftStudio] has been working on just such a project, creating custom wedge lights to illuminate garden beds in style.

You might look at the plastic housings involved and assume that they’re 3D printed, like the vast majority of such projects we cover these days. Instead, the enclosures are crafted out of PVC plastic, harvested by flattening sections of pipe with a heat gun. It has the benefit of being highly weather resistant, and cheap to boot. The lights themselves are small LED panels mounted on aluminium plate as a heatsink, and fitted with an acrylic diffuser to spread the light out more evenly. Power for the lights comes from an 18650 lithium-ion cell, charged by a pair of solar panels hooked up to an MPPT charge controller. A TP223 capacitive touch module is also included in the design to allow the lights to be turned on with just the touch of a finger.

The result is a surprisingly stylish bit of garden furniture which provides warm, even light and, ideally, needs a minimum of maintenance and attention since the sun provides the power. We’ve featured some other great solar lamps before, too, like this lovely Pokemon-themed build. If you’re building your own solar projects at home, or doing weird things with PVC, we’d probably love to hear about it on the tipsline!

This Week In Security: BugTraq, AI Hacks, And Being Dumb On Planes

After a multi-year hiatus, the venerable BugTraq mailing list is back!

For decades, BugTraq was the place where vulnerabilities were disclosed, from the early days when nearly all vendors viewed all security research as a hostile force, through to the modern era of working with vendors to coordinate disclosing bugs. With the rise of bug bounty programs and other social changes, the mailing list slowly died: what started in 1993 ended in 2021 is returning. The new maintainer, Jonathan Brossard, says in his announcement “The mission is unchanged: full disclosure, researcher-first, no corporate filter.”

Don’t Be Dumb on Planes

In the unlikely event anyone here needs to be told: Don’t do dumb things on planes.

It seems that someone coming home from from the DEF CON hacker conference in Las Vegas decided to mess with the in-plane WiFi, and is likely now in the “find out” phase of doing something dumb. There hasn’t been any public followup beyond the original reports: a passenger on a Delta flight leaving Las Vegas brought up a fake WiFi hotspot named “Delta WiFi FAST” to trick other passengers into connecting, and attempted to disable the in-flight WiFi using a denial of service attack.

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Off-Grid OCR Server Powered By IPhone

Running an optical character recognition (OCR) server might sound like it would need some powerful hardware, like a rack-mounted, water-cooled machine, or at least a nice desktop or laptop. But if you have the time, anything could be used. [Hemant] has a long-running personal project that processes a lot of image data over a long time, and set up the OCR server on an iPhone 8 running entirely with solar power, rather than turn to more typical hardware.

Part of what makes this task feasible for low-powered hardware is Apple’s Vision framework, which uses machine learning to aid in things like character recognition (among other tasks). It will run on an iPhone just as easily as a Mac. The phone’s built-in battery already provides the first step of an off-grid setup. This build relies on a separate power bank to integrate the phone with the solar panel more easily. On the software side, [Hemant] reports that the true challenge wasn’t setting up the server as much as it was keeping the iPhone from sleeping or stopping his program from running full-time.

A system like this running off-grid, especially considering the costs of the solar panel and power bank, might seem counterproductive. But when comparing electricity costs for running the same software on his server, he estimates he saves about $10 per month with this setup, which has a payback of somewhere around 2-3 years. Not too bad for a phone that would have otherwise ended up in a landfill. Old phones can be surprisingly good choices for servers, too. It helps if they can run Linux, but plenty of phones will support server applications, even when running their native OS.

Adding Capabilities To Inexpensive Solar Modules

Solar power has gotten cheap enough that putting up panels is among the cheapest ways of providing energy. This isn’t just the case for bulk electricity on a power grid, either; even small devices are easier and cheaper to power with solar than ever before. For example, landscape lighting which once relied on 12V or 24V DC wires all over one’s yard with a transformer and power supply hidden somewhere have partially been converted to simpler individual solar-powered lights now. These small devices can also be given additional capabilities as [Mauro] demonstrates.

In this case, [Mauro]’s goal was to add on-demand lighting to a solar-powered light which was otherwise motion-activated only. To do this, they added a NRF24L01+ radio inside the light’s housing paired with an STM32 microcontroller. This secondary system is largely separated from the existing control circuitry with the exception of being able to switch the lights and receiving its power from the same solar panel. [Mauro] also created a small library to help with communicating with these new modules, whether that’s using a home automation system like Home Assistant or some other method.

Although adding in a few capabilities to inexpensive solar lighting might seem simple on the surface, a project like this is a gateway to adding in all kinds of interesting features to things with built-in solar panels and lots of free space in their cases. The best example here is the addition of a Meshtastic node to one of these lights, making it convenient and stealthy, but we could also see adding in other remote hardware to a landscape lighting module like a gate sensor or a plant health monitoring system.

Making A DIY Refrigerated Vest With Battery And Solar Power

Keeping a cool head is difficult at the best of times, least of all when it’s summer and merely thinking of touching bare skin to the pavement already gets you a second-degree burn. Unfortunately, it’s not possible to spend all summer in an air-conditioned room, but what if you took said room with you? Introducing [Hyperspace Pirate]’s air-conditioned vest.

Following on from last time’s adventures with a battery-powered air-conditioner that merely blew cold air onto one’s overheating body, this time the same compressor is used for a more compact build.

Since obviously using your body as part of the evaporator would be uncomfortable, instead a heat exchanger was used that transfers the delicious frosty cold to water-filled tubing, zip-tied inside a very fashionable vest.

The basic unit runs on a couple of LiPo packs, but a solar-powered circuit was also built and tested using two small-ish panels. Of course, the requisite backpack-sized setup for that configuration is somewhat bulky, but at least the panels can also provide shade in addition to power for the compressor, hitting two fiery birds with one frosty stone.

Compared to one of those solar-powered caps with a built-in fan, this unit with some refinement could actually be an improvement, as well as keeping you a lot chillier. We’re looking forward to [Hyperspace]’s trial runs in the upcoming Floridian summer, as well as future chilling adventures.

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Solar Supercapacitor Lamp Probably Won’t Get You Saved At Sea

Most solar lights are cheap garbage that exist just to put more microplastics into the environment as they degrade in short order. [Jeremy Cook] built his own solar light, however, and this one might just last a little longer.

Most solar lights rely on the cheapest nickel-cadmium or nickel-metal hydride cells that are available on the market. They don’t tend to have a lot of capacity and they wear out incredibly fast. [Jeremy] went a different route for his build, though, instead relying on a rather tasty supercapacitor to store energy. Unlike a rechargeable battery, that may only last a few thousand cycles, these supercaps are expected to perform over 500,000 charge/discharge cycles without failure. With such longevity, [Jeremy] suggests his build could last a full 1369.8 years, assuming it charged and discharged once a day. Whether the plastic transistor, LEDs, or diode could hold up over such a long period is another question entirely.

Electronically, the build is relatively simple. The solar panel collects light energy and turns it into electricity, charging the supercaps through a diode. The supercaps are only able to discharge through a transistor, which only turns on when the voltage output by the solar panel drops at night time, and the voltage on the base becomes lower than that on the emitter. When current flows through the transistor, it then lights the LED in turn and the device glows in the darkness. As a nice touch, the whole circuit is installed in a glass jug of syrup originally sourced from Costco. Files are on Github for those eager to explore further.

Given the light-in-a-bottle construction, [Jeremy] also playfully imagined that a lamp like this could theoretically be used as a safety device. If lost at sea, you could charge it using the sun and try and use it to signal for help. However, upon casually exploring the concept, he notes that a small solar-powered light will only raise the chance of a far-off ocean rescue from “extremely unlikely” to “still very unlikely.”

You can do all kinds of neat things with free energy from the sun, from mowing your lawn to processing waste products. Video after the break.

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Damn Fine (Solar Powered) Coffee

The folks at Low Tech Magazine are here again, this time with a solar powered coffee maker. Lest you think of a large parabolic mirror with a pot at its focus, in this case the device is much more friendly. It’s a table-top appliance that relies upon a 100 W, 12 V panel for its operation.

They make the point that an electric coffee pot requires at least 300 W to work, so what’s the secret? In this case, insulation, as a standard moka pot is placed within a nichrome heating element set in mortar and surrounded by cork. On the outside are tiles, though they appear largely ornamental and the write-up suggests you could experiment with other materials to serve as an enclosure.

It appears to be an effective coffee maker, with the significant caveat that it’s hardly fast. In full sunlight the first pot takes over an hour to brew, with subsequent ones once it’s up to temperature being somewhat faster. But you can’t argue with the idea of free power, even if your favourite caffeinated beverage may now take a while to appear.

We like this idea, despite its slow brewing. We’ve featured Low Tech Magazine before, not least in their solar powered oven.