When looking at integrating a photovoltaic solar panel into a project, the naive assumption would be that you simply point the panel into the general direction of where the Sun is, and out comes gobs of clean DC power, ready to be used for charging a battery. To a certain extent this assumption is correct, but feeding a solar panel’s output into something like a regular old PWM buck or boost regulator is unlikely to get you anywhere close to the panel’s full specifications.
The keywords here are ‘maximum power point’ (MPP), which refers to the optimal point on the solar panel’s I-V curve. This is a property that’s important not only with photovoltaics, but also with wind turbines and other highly variable power sources. The tracking of this maximum power point is what is generally referred to as ‘MPPT‘, but within this one acronym many different algorithms are covered, each with its own advantages and disadvantages. In this article we’ll take a look at what these MPPT algorithms are, and when you would want to pick a particular one.
Continue reading “Maximum Power Point Tracking: Optimizing Solar Panels”
Plenty of electronics end up in the junk drawer or even landfill after their useful life ends, but in the modern world of planned obsolescence a lot more devices are thrown out simply because of lack of support. Sometimes it’s even worse than that as some products are designed to “phone home” and will lack critical functionality if the original producer of that product gets purchased by someone else, wants to sell its customers more products, or goes out of business. The latter is essentially what happened to the Ouya console, but if you still have one of these around you might be able to get it running again.
The Ouya was a commercial failure but an ambitious take on a new kind of gaming console. With little more processing power than a smart phone, the idea was to produce a console for the casual gamer that also could play retro games and other games available for Android. It had a low price point but eventually couldn’t sell enough units to stay in business. These devices needed to see a specific server to gain full functionality, and [Christian] has created essentially a spoofed server that allows users to sign in to their consoles and install games again. All that is needed is to modify a few config files on the Ouya to point to a different address and the Ouya boots up just like it’s 2012 again.
This project goes a long way to show that there are plenty of serviceable electronics out there that have just been needlessly borked, and with a little elbow grease it’s sometimes possible to get them working. The state of this machine is a little surprising given that the original machine promised to be hacker and developer friendly.
Thanks to [Josiah] for the tip!
No spooky mansion is complete without a secret passage accessed through a book shelf — or so Hollywood has taught us. What works as a cliché in movies works equally well in an escape room, and whenever there’s escape rooms paired with technology, [Alastair Aitchison] isn’t far. His latest creation: you guessed it, is a secret bookcase door.
For this tutorial, he took a regular book shelf and mounted it onto a wooden door, with the door itself functioning as the shelf’s back panel, and using the door hinges as primary moving mechanism. Knowing how heavy it would become once it’s filled with books, he added some caster wheels hidden in the bottom as support. As for the (un)locking mechanism, [Alastair] did consider a mechanical lock attached on the door’s back side, pulled by a wire attached to a book. But with safety as one of his main concerns, he wanted to keep the risk of anyone getting locked in without an emergency exit at a minimum. A fail-safe magnetic lock hooked up to an Arduino, along with a kill switch served as solution instead.
Since his main target is an escape room, using an Arduino allows also for a whole lot more variety of integrating the secret door into its puzzles, as well as ways to actually unlock it. How about by solving a Rubik’s Cube or with the right touch on a plasma globe?
Continue reading “A Classic TV Trope For An Escape Room”