Google Cardboard button for Z3 (compact)

The new Google Cardboard supposedly works with "every phone" I guess that means they have moved the magnet in so that it is harder for the magnetometer to just filter out the button. As is the case with for example my Z3 (compact) which just plain out ignores the button on my knock-off Cardboard and supposedly on a few other cardboard owners phones. There is at least one person that has bothered to make a hack to get it to work, but it is not very pretty, requires access to copper tape and looks a bit fiddly if you remove and re-insert the phone. So here is my attempt at adding a touch-button to my Google Cardboard.

Using the Google Earth demo I made a piece of aluminium foil that exactly covered that area of the
top half of the screen (if you touch the lower part of the screen the button-bar will pop up). If you do this you might want to cover your screen with a sheet of paper or some plastic so you don't scratch it up

My phone completely ignored touch on this, even if I extended it to cover the entire width of the screen.

This was how ever apparently not a problem with the use of aluminium foil as such, since it detected a click when I removed the foil. Apparently the phone is doing some kind of palm-detection or similar, so using a blunt-tip non-conductive manipulation-rod (aka whiteboard-pen) I retracted the foil until it consistently detected clicks on the other end of the foil.

After that I cut some card-stock to the same width as the foil and eye-balled it to be slightly wider than one of the eye-pieces. I then pulled the card-stock over the edge of a table to give it an arch-shape, and trimmed it down so that it would be a millimetre or two longer than the right eye-piece, in order to assure that the foil would be held firmly against the screen.

Most paper-glues wont adhere to metals, and I wanted something flexible so the usual cyanoacrylate super-glue would not quite do. Wrapping the foil in a single layer of clear tape is an easy fix, also reduces the risk that the foil will scratch the screen.

Please note that the foil is not quite taped on all the way. this is so that the card-stock can be better affixed to the cardboard.

To avoid that the added force of the finger-adapter would dislodge the flimsy mid-piece of cardboard I reinforced it with some more tape, if it still gets dislodged I guess I will add a blob of heat-glue

 I made it slightly S-shaped to provide the most pressure around 1cm from the end of the foil and taped it on on both side, note that the tape on the out-side goes under the foil- connecting the card-stock and the cardboard, since the foil is a bit flimsy, and I wanted to reduce the risk that having a layer of tape between the finger and the foil might interfere with the workings. Instead I just taped the tip of the foil to the side of the box, leaving a few millimetres exposed.

It doesn't look  very pretty, but it works.