Introduction: Real Augmented Reality™: Burnerphone and Other Phenomenal Realities
Real Augmented Reality is when the real world is augmented with overlays that are also "burned" or cut or inscribed into the real world.
For example, I wanted to make an art piece in which otherwise invisible radio waves are overlaid upon reality in the physical world, so you don't need special eyeglasses or other apparatus to see the augmented reality content.
I call this piece "Burner Phone" == a phone that burns its waves into the real world in which it inhabits.
I make these kinds of art pieces from old discarded phones that would otherwise decorate landfill sites.
Step 1: Catch the Wave
Once you have an old phone you want to turn into Real Augmented Reality™ art, you need to get it working for just long enough for it to spit out its last signal transmission -- its "swan song" so-to-speak.
Now ideally we want to actually burn the waveform into something like a piece of wood directly, i.e. to "SWIM" out the wave, to a mechanism that will burn it right into the wood.
One of the great things about a place like Pier 9 (world's greatest workshop for sure!) is the willingness there to entertain new ideas, but at the same time we really need a device we can "hack". In my younger years I used to hack X-Y plotters and get them to inscribe waves into things, but here in the modern age it is much harder to "hack" things at a fundamental level.
So instead, I offer an easy (though somewhat less elegant, philosophically) approach, namely that of capturing the wave, and then transferring it to the Epilog laser cutter to cut into the wood.
The capture is by way of SWIM as outlined in previous Instructables (see also the Instructable on making furniture out of recorded waves). The above diagram summarizes how it works, i.e. there's a reference antenna that sits stationary right next to the item under test (e.g. the phone) and it is connected to the reference input of a Lock-In Amplifier (LIA) or other phase coherent detector. A moving antenna sweeps across, and the moving antenna is connected to the signal input of the LIA. The output of the LIA (e.g. the in-phase output, "X") is connected to the SWIM. Refer to my previous Instructables on SWIM for more info, and here's a nice magazine article giving some historical context (link). T-SWIM is like SWIM except that it is also tactile, arising from the fact that T-SWIM is mechanical (the light source moves up-and-down with a servo motor, typically, rather than being sequenced by LEDs). T-SWIM is the original SWIM and then later I used sequences of lights, but the tactile element of SWIM was missed so I then added a transducer to vibrate the SWIM and bring back what was lost in going to the electronic rather than mechanical version of SWIM == it is wonderful to be able to feel the wave as well as see it!
The important thing here is to make sure you get the scale right, because the wave needs to be recorded as if it came from the phone (i.e. the same result as if a T-SWIM was used to inscribe it directly).
Note that the wave should be captured from exactly the same place where the art will be hung, because when you record the wave, you're capturing also the reflections off walls, and other areas of the building. You can see how the wave gets weaker as it gets further from the antenna, but then it gets stronger again even further on. This is due to reflections off other objects in the room. Thus once this is recorded at a particular location, and then burned into the wood, the art needs to ultimately hang where the wave was captured, so that it is true and accurate a depiction of the radio waves in that exact location.
The wave is captured by turning off all the lights, sweeping the SWIM across in a dark room, and making a long-exposure photograph of this process with a light source attached to the T-SWIM (or a linear array of lights used for a regular SWIM).
Step 2: Process the Waveform and Make Sure the Scale Is Exactly 1:1
Here we have a photograph of a blue LED that was attached to an X-Y plotter sweeping across left-to-right while carrying a signal antenna to scan the waveform from a cordless phone and capture it in a dark room.
The first step is to negate it (take the negative of the photograph) and then scale it exactly 1:1.
The transmitted signal of the cordless phone was 5.8 GHz so the wavelength is the speed of light divided by that:
λ = 300,000,000 m/s / 5.8*109 /s = 5.6cm.
Using a ruler on the original recording device, confirm and double check the scale of the original recording.
Make sure that the scale of the laser cutting file is such that there are exactly 5.6cm for each cycle of the waveform.
Also make sure that the starting point is correct. For a given gain, the signal strength increases without bound toward the antenna, so there is an artistic decision to be made as to the boundaries of the signal as recorded onto the wood or other material.
Step 3: Burn It!
Now burn the wave into the wood.
I experimented with various levels of strength on the beam and found the best settings.
Also the wood should be placed so that the bottom of the art piece is toward you.
In this way the smoke coming from the wood will stain the wood above the trace, as the smoke is drawn out the exhaust of the unit, which is correct for visual appeal (i.e. the smoke stains look good when they rise above the waveform pattern rather than below it which would look unnatural when the work is hung on the wall).
Step 4: Mount It.
Now all you have to do is drill some holes to mount the phone, and then hang the finished work.
I usually drill 2 holes and attach the phone with a piece of stiff wire.
The phone should be mounted in the same place corresponding to where it was when the original recording was made.