A Rough And Ready Pan & Tilt Mirror

There’s nothing quite like waking up on a warm and sunny morning, with the sun filtering in through the windows over a magnificent beach view. Of course, in real life, not every bedroom has access to beautiful natural vistas and abundant natural light. [Rue Mohr] decided to try and solve this issue with technology.

The initial write-up may be brief, but the pictures of the resulting project show a proper hacker’s build. A stand for an old office chair appears to serve as the base, and the mirror is mounted on a frame that allows for both pan and tilt to be adjusted. There’s a large gear to enable pan rotation, which meshes with a nifty old-school cage gear built out of what we suspect is plastic and welding rod. An AVR microcontroller is charged with running the show, with it interpolating a series of waypoints to set the mirror’s position throughout the day.

[Rue] reports that the project is nearing completion, and is soon to be fully automated. With the dark bedroom that spawned the project no longer a concern, the mirror will instead be pressed into service to provide sun to a row of bean plants.

If you’re looking for a pan-tilt mechanism, but something a little smaller, this 3D-printed mechanism might be just what you’re after.

Text Projector With — You Know — Lasers

We missed [iliasam’s] laser text projector when it first appeared, perhaps because the original article was in Russian. However, he recently reposted in English and it really caught our eye. You can see a short video of it in operation, below.

The projector uses raster scanning where the beam goes over each spot in a grid pattern. The design uses one laser from a cheap laser pointer and a salvaged mirror module from an old laser printer. The laser pointer diode turned out to be a bit weak, so a DVD laser was eventually put into service. A DVD motor also provides the vertical scan which is just a slight wobble of a mirror. A Blue Pill CPU provides all the smarts. You can find the code on GitHub.

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Magic Mirror Tirelessly Indulges Children’s Curiousity

[pepelepoisson]’s Miroir Magique (“Magic Mirror”) is an interesting take on the smart mirror concept; it’s intended to be a playful, interactive learning tool for kids who are at an age where language and interactivity are deeply interesting to them, but whose ceaseless demands for examples of spelling and writing can be equally exhausting. Inspiration came from his own five-year-old, who can neither read nor write but nevertheless has a bottomless fascination with the writing and spelling of words, phrases, and numbers.

Magic Mirror is listening

The magic is all in the simple interface. Magic Mirror waits for activation (a simple pass of the hand over a sensor) then shows that it is listening. Anything it hears, it then displays on the screen and reads back to the user. From an application perspective it’s fairly simple, but what’s interesting is the use of speech-to-text and text-to-speech functions not as a means to an end, but as an end in themselves. A mirror in more ways than one, it listens and repeats back, while writing out what it hears at the same time. For its intended audience of curious children fascinated by the written and spoken aspects of language, it’s part interactive toy and part learning tool.

Like most smart mirror projects the technological elements are all hidden; the screen is behind a one-way mirror, speakers are out of sight, and the only inputs are a gesture sensor and a microphone embedded into the frame. Thus equipped, the mirror can tirelessly humor even the most demanding of curious children.

[pepelepoisson] explains some of the technical aspects on the project page (English translation link here) and all the code and build details are available (in French) on the project’s GitHub repository. Embedded below is a demonstration of the Magic Mirror, first in French then switching to English.

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Laser Projector Ditches Galvanometer For Spinning Drum

Laser projectors like those popular in clubs or laser shows often use mirror galvanometers to reflect the laser and draw in 2D. Without galvos, and on a tight budget, [Vitaliy Mosesov] decided that instead of downgrading the quality, he would seek an entirely different solution: a spinning mirror drum.

He fires a laser at a rotating drum with twelve mirror faces, each at a different adjustable vertical angle. The laser will hit a higher or lower point on the projection surface depending on which mirror it’s reflecting off – this creates resolution in the Y direction.

Timing the pulsing of the laser so that it reflects off the mirror at a certain horizontal angle provides the X resolution.

As you can already tell, speed and timing is critical for this to work. So much so that [Vitaliy] decided he wanted to overclock his Arduino – from 16 MHz to 24.576 MHz. Since this changes the baud rate, an AVR ISP II was used for programming after the modification, and the ‘duino’s hardware serial initialization had to be hacked too.

For the laser itself, [Vitaliy] designed some nifty driver circuitry, which can respond quickly to the required >50 kHz modulation, supply high current, and filter out voltage transients on the power supply (semiconductor lasers have no protection from current spikes).

On the motor side of things, closed loop control is essential. A photo-interrupter was added to the drum for exact speed detection, as well as a differentiator to clean up the signal. Oh, and did we mention the motor is from a floppy disk drive?

We’ve actually seen builds like this before, including a dot-matrix version with multiple lasers and one made apparently out of Meccano and hot-glue that can project a Jolly Wrencher. But this build, with its multiple, adjustable mirrors, is a beauty.  Check it out in action below.

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This Vapour Deposition Chamber Isn’t Vapourware

If you are an astronomer with an optical reflecting telescope, the quality of your mirror is one of your most significant concerns. Large observatories will therefore often have on-site vapour deposition plants to revitalise their reflectors by depositing a fresh layer of aluminium upon them. You might think that such a device would be the preserve only of such well-funded sites, but perhaps [Michael Koch]’s work will prove you wrong. He’s created his own vapour deposition system (Google Translate link of the German original) from scratch, and while it might be smaller than the institutional equivalents it is no less effective in its task.

At the heart of it is a stainless steel vacuum vessel with a two stage vacuum pump system to evacuate it. The mirror to be silvered is suspended in the vessel, and a piece of aluminium is suspended over a coil of tungsten wire that his electrically heated to melt it. The molten aluminium is described as “wetting” the tungsten wire in the same manner as we’ll be used to solder working on copper, but in the vacuum it vaporizes and deposits itself upon the mirror. Such a simple description glosses over the impressive work that went into it.

This is a long-running project that isn’t entirely new, but very much worth a look if only for its introduction to this fascinating field. If you are new to vacuum work, how about looking at a Superconference presentation introducing vacuum technology?

Thanks [Paul Bauer] for the tip.

Clever Approach To Stylus Alignment

Digitally stored music is just data. But not long ago, music was analog and required machines with moving parts. If you have never owned a record player, you at least know what they look like, now that there’s a(nother) vinyl revival. What you may not be aware of is that the player’s stylus needs to be aligned. It makes sense, that hypersensitive needle can’t be expected to perform well if it’s tearing across a record like a drift racer.

There are professional tools for ensuring alignment, but it’s not something you’ll need each day. [Ali Naci Erdem] shows us his trick for combining a printable template with a mirror to get the same results without the professional tool costs. Instead of ordinary printer paper, he prints the template on a piece of clear plastic and lays it across a small mirror. These are both items which can be picked up at a hobby store, which is not something we can say about a record player mirror protractor.

We love music hacks like this informative introduction to circuit bending, the wonderful [Martin] from Wintergatan, or if you want to get weird, an organ made from Furbies.

Flowing Light Art Inspired By Plankton

With today’s technology, art can be taken in directions that have never before been possible. Taking advantage of this, [teamlab] — an art collective from Japan — have unveiled an art installation that integrates the attendee into the spectacle. In the dark room of the piece ‘Moving Creates Vortices and Vortices Create Movement,‘ you are the brush that paints the flowing display.

Inspired by the movement of ocean plankton, this borrows your movement to create tapestries of light with mirrored walls to aggrandize the effect. As attendees walk about the room, their movements are tracked and translated into flowing patterns projected onto the ground. The faster the people move, the greater the resultant flow. Even those who have stopped to take in the scene are themselves still part of it; their idle forms mimic boulders in a river — as eddies would churn about the obstacle, so too does the light flow around the attendee.

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