So, hear me out - first, I'm a CTO and so I wind up buying a lot of them for experimentation, plus they also sort of show up when you buy things these days. I purchased a new TV a few months ago, and...poof, tablet. Then, of course, there's the actual tablets that I use in my personal life.
The problem with tablet proliferation is: they are all really pretty nice, so you don't want to get rid of them - but as technology moves on, the older ones get left by the wayside. Either the operating system doesn't upgrade any further, or the hardware can't support the new operating systems. The two tablets I'm going to talk about fall into those last two categories: The Samsung Galaxy Tab 7+ and the Asus Transformer Prime.
Unfortunately, the 7+ is stuck on Android 4.0.x, and doesn't look like it's going to be updated any further. Pity, but... it's time for a new life.
It's sad, because the screen was really phenomenal, but...now it too will get a second life.
For years I've wanted a kitchen computer (anyone remember Audrey?) - but they were always too large, too unreliable, and too difficult to install cleanly. Pre-iPad tablet computers existed, but they were extremely expensive and prone to overheating. Plus, they really couldn't do much in the way of home automation.
Enter 2013: tablets are plentiful (and lying around my home office, apparently), and home automation has seen a resurgence (Nest, Sonos, Media Center, alarm systems, etc.) - this seemed to be the perfect opportunity to use what I had to create a low-cost JARVIS for my house. One "JARVIS" would be in my bedroom (the Tab 7+) and the other would be in my kitchen (the Asus). This would allow me to experiment with different configurations and interoperability between the two units, and see what sort of additional kick to my home automation I could provide.
the alterations easier. To be honest, I went through a couple of frames ($25/pop) until I got the effect I was looking to achieve. Once done, I had to do it again with the second frame, then paint over the new seams. I kinda impressed myself.
Whilest I haveth ye ole wood chisel in my hand, I continued my hacking away to place two screw mounts on either side of the frame. It was important to make these mounts as flush with the wood as possible, as it is important that the frame mounts tight and flush against the wall. It's a touch screen interface, and the rig can't bounce around on the wall when your poking at it.
The final cut to make into the frame had to be far more precise than my hack jobs. As I mentioned above, android tablets have a lot of sensors on board, but the one they do not have is a proximity sensor. On phones, the proximity sensor allows the phone's screen to either wake or go to sleep when the phone is placed close to, or taken away from, your face so your cheek doesn't accidentally hang up the phone or punch buttons. On a tablet, you rarely hold it to your face so the OEMs save themselves a sensor and just have the user touch the physical "on" button to wake the screen.
What this means for this project is that there is no software I can write, or applications I can download, that will allow me to wave my hand in front of the tablet to wake it up. I literally have to "punch the button" to get it to wake up. This is fine when the tablet is just sitting on the table, but punching the button is difficult to do when it's covered up by two inches of wood and screwed into the wall.
My solution to this problem was old-world mechanical: create a button mechanism that extends through the frame.
I don't own a drill press, so I used a vise and a steady hand to drill a 5/8th inch hole through the frame to where the tablet power button sits. I then cut a 2.5 inch length of 5/8th inch dowel stick, and shaped the end (with sandpaper) that would come in contact with the power button to conform to the shapes of the tablet edging. (Note: Aside from the Sony Tablet Z, there's no tablet I'm aware of that has a flat edge bevel. Both the Samsung and the Asus have tapered edges that need to be taken into account, otherwise the dowel will not seat properly against the button.) When I initially cut out the framing, I arranged the tablets so that their power buttons are on "top" of the frame, and the dowel stick just rests on top. I had to do a little extra sanding on the dowel stick itself to reduce friction when it was in the hole, otherwise I ran the danger of the dowel being held down against the power button causing the tablet to reboot.
Ta-da! A wooden "instant wake" button.
Keeping the tablets in place in their framing was easier than I anticipated. I cut poster board to fit the backing of the frame, drilling a hole in the back to allow the cable to come through. The poster board was then held in place by simple metal clips that you can purchase at any framing store.
That's it - both units are now ready for wall mounting.
I'll spare you the gory details, but I took down the ADT security panel (revealing that lovely hackjob of a hole in the wall that the installation dude cut) and moved it down about 9 inches. Similarly, I pulled off the 40 year old security gate phone (70's wiring is amazing, uh....really) and moved it over about 5 inches. With the old equipment positioned as you see it in the photo, I was now ready to install the kitchen "JARVIS."
Fortunately, as I had hoped, the interior wall was completely hollow. "Wiring" in the unit, just
required me to attach the USB extension cable, electrical tape it together, and drill a 3/4" hole near the baseboard on the opposite side of the wall, which was next to an electrical outlet. If you are familiar with using a coat hanger to fish wires, the rest was very straightforward. (If you aren't familiar with using a coat hanger, uh, it's pretty much exactly what you are thinking: unbend it, make a hook in one end, and use it to fish the dangling cable through the hole.
Once all of that was done, placing the drywall screws in the wall where the tablet would be mounted was a snap. Just make sure you level the holes, measure twice, drill once. The tablet snapped right in without any trouble, and the dowel-stick mechanical button worked as advertised.
Voila! A neat, clean wall tablet installation.
What this meant for the installation was, well, messy. I had to drill the 3/4th's inch holes for the USB cabling both at the tablet mount point, and down below by the baseboard, just like in the kitchen - unlike, the kitchen, however, I would have to locate the stacked 2x4's that were taking the
weight of the window frames and chisel a channel for the cable through them...which, of course, meant channeling through the drywall. This went from a simple drill-and-hang operation to one that involved wall patching and painting. So be it...I had extra wall paint in the basement.
Once the channel was cut into the wall, threading the USB cable was just like the kitchen, except I used anchor staples to attach the USB cable to the 2x4's so it wouldn't be able to move or slide around - once that was done, I patched the wall up and hung the frame for the bedroom "JARVIS" as intended, making sure that everything was level.
Because of the amount of patching that was done, I waited 24 hours for the wall to dry. Once I was convinced it was dry, it was just a matter of applying the wall paint and hanging the tablet.
Volia (again)! Bedroom JARVIS.