Imagine that a guest is about to depart from your house. She (or he) pauses to check her appearance in an antique-looking mirror mounted near the front door. Suddenly, the image of your guest undergoes a Matrix-like 'ripple' and is replaced with a strange face saying…
…actually, we'll move on to consider what the face might say in a moment, but first let me introduce you to a few underlying concepts. Just a few days ago as I pen these words, I came across about a very cool website that describes a really cunning idea called a Magic Mirror (http://diymagicmirror.com).
The idea is that we first mount a flat-screen liquid crystal display (LCD) flush with the wall of our house (cutting into the drywall is the part my wife is not going to be deliriously happy about, but we'll cross that bridge when we come to it [grin]). Next, we acquire a piece of special glass that acts as a two-way mirror. If we place this special glass over a black surface it will appear to be a normal mirror; if there's a light source behind the glass, however, then that light will pass through. So the idea is to take the glass, mount it in an antique picture frame, and hang it on the wall covering our LCD screen.
All we need now is a proximity detector that determines when someone is standing in front of the mirror and a computer that we'll use to drive the display. When someone stands in front of the mirror, we want the proximity detector to send a signal to the computer, which should pause for some short delay (maybe a second or so) and then start to display whatever image, video, or other data we decide to use.
I tell you; as soon as I heard about this my first reaction was to chastise myself soundly for not inventing something like this on my own. My next reaction, of course, was to jump up and down shouting "I want one of these to play with!"
On the one hand, I have to say that the folks at the DIY Magic Mirror site have done a really good job. In addition to a bunch of "How To" videos, for example, they've also created some clever software that can display a variety of animated faces on the screen, including a text-to-speech capability so you can get the "talking head" of your choice to say whatever you wish. This software can also present information culled from the Internet such as stock prices, your local weather forecast, and all sorts of other "stuff". You can download a demo copy of this software for free, or you can purchase a full-up version for around $50, which really isn’t too bad.
From the Magic Mirror site you can also purchase a small hardware "box" into which you can plug a variety of sensors. This box connects to your notepad computer via a USB cable and triggers the software running in the notepad computer to leap into action. However, the cost of the sensor box (without sensors) and the software to run on your computer is $219, which is starting to get a teeny-weeny bit expensive…
On the bright side, we don’t actually need any special software or sensors and suchlike to construct a proof of concept. All we really require is a piece of the special two-way mirror glass, an inexpensive LCD display, and – optionally – a nice antique-looking frame just for effect. In my case, I can start off using my personal notepad computer to display videos and suchlike.
Step 1: Acquiring the special two-way mirror glass
This part was easy-peasy. In the future I might decide to create a bigger unit, but for the moment I'm simply creating a proof of concept, so I followed the advice on the Magic Mirror site and ordered a 12" x 12" sample of this dielectric glass ($19.95 plus shipping and handling) from HiddenTelevison.com
This looks like normal glass until you hold it up to a dark surface.
Although 12" x 12" might not seem very large, it's sufficient to cover a 15" diagonal LCD Monitor with a 4:3 aspect ratio, which is what I'll be playing with at first. A couple of days later a box arrived containing the very carefully packaged glass as shown above.
Step 2: Acquiring an inexpensive LCD display
As you may recall from previous blogs on my hobby projects, I'm easily enthused and tend to leap into action with gusto and abandon. Thus, you have to understand that my starting this project commenced within minutes of my running across the original Magic Mirror site. As soon as I'd placed my online order for the special two-way mirror glass, I headed out to my local technology recycling center, which is located just around the corner from my office (this is fortunate for me since I spend so much time there).
My LCD monitor seconds before I attacked it with a screwdriver.
Hurray! I managed to pick up a very nice 15" LCD monitor for only $45 (and there's no tax because they don’t tax recycled technology for some reason).