Wear me
One of my ongoing goals in my techno-lifestyle is to build myself an extension fo a PDA that’s even more like a full-fledged computer. Somewhat heading down the road of the MIThril project at MIT, and other such “cyborg” systems, but not so deep. The MIThril system has RFID and card scanning systems that would be a bit overkill for my daily use, but what I envision is a system that is optimized for note taking while seated at a small table/desk, as well as walking about. One of the main problems with a laptop is the ability to use it while walking. There’s the issue of looking down at the laptop screen vs. looking up where you’re supposed to be going, and the weight and awkwardness of holding a laptop in one hand and typing/mousing with the other.
I’ve looked at the SeV “Technology-Enabled clothing” lines, but those more seem to be a way to organize your techno-clutter and make having multiple devices for multiple things be not an issue, while I’d like to see one, integrated system to do what I need.
So, I’ve been toying with a setup for a while, and thought I’d get it out in print to flesh it out:
Rather than design a vest or other outerwear that would fit a computer inside it, I’ve picked up a messenger bag at a recent conference my company hosted, which I’ll work into the vessel. I’d rather not have it be an actual piece of clothing, since then wearing it every day gives the appearance you’re wearing the same clothes every day, and I both don’t want to seem that socially awkward, and don’t want to make the design out of e-Ink to be able to change its appearance continually. So my goal is to turn this bag into a laptop. Not a laptop bag (for carrying a laptop), but a bag laptop (a bag that is a laptop. You follow?).
To power this mobile device, I’d create a power system in the bag, which would likely get power from the sun (like this bag modification), or could plug into AC power to charge. That linked bag modification is for a setup that doesn’t store the power coming off the solar panel; it only goes into a device if it’s plugged into one, and is only enough power to charge a cell phone or iPod. Instead, I’d likely set up something like a Tekkeon MP3450 battery inside the bag, which would gather the power continually and in turn power the wearable machine. I know that the solar panel wouldn’t have enough surface area on the bag to provide enough power to run a laptop (the example given is a 5–6V solar cell, while laptop AC adapters use 12V to charge the laptop). The Tekkeon battery doesn’t give specs on how much charge it actually holds, though from the accessory cables for the SUNLINQ solar system, the Tekkeon could be trickle-charged on a lesser voltage and store the charge.
Then, for the device itself, there would be a nano-ITX-based computer hidden in one of the pockets. Most of the cases for nano-ITX motherboards assume that if you’re opting for the 12x12cm footprint size, you’d rather go up in dimension rather than out, so the cases put optical drives and hard drives on top of the motherboard, adding thickness. For sliding into a bag, I’d want it to be laid out as flat as possible, so I’d have to make a custom enclosure with a 2.5" hard drive sitting next to the 12x12cm board, to fit best in the bag. Add to this a USB Bluetooth dongle and a Bluetooth FrogPad for input, and a monocular display unit (like the M920 for a display. Then install a non-power-hungry OS on the system (Xubuntu would be a likely choice, as it uses Xfce as a desktop environment, which is tailored for speed and lightness.
The couple of downsides that still need to be overcome is wiring for the power system: I don’t know how to wire up a circuit that safely routes incoming voltages from a solar panel and from an AC transformer safely (though it looks like the Tekkeon model does that automatically, as it has different input sockets for the solar panel charging and the AC charging), but I’m guessing there are plans out there somewhere if I were to attempt my own generic battery setup, rather than something more expensive like the Tekkeon.
The cost of the monocular display units are still quite expensive (the M920 model going for a whole laptop could cost), though they get more expensive if they’re set up with VGA inputs designed for laptop display. Models that only have S-Video input may be less expensive (and perhaps there are grayscale displays rather than color?), and many of the nano-ITX boards have S-Video or composite outputs directly. Also, some of the head-mounted display systems have their own battery pack. The M920 can run off of USB power (5V), so could plug into the nano-ITX motherboard and pull power there, but others would likely have to be hacked to not use AA or AAA battery packs.
The Tekkeon statistics for the MP3450 say that it only powers a laptop for 3.5 hours, where ideally, this mobile device would have enough power to last throughout the day (10 hours) in the field. If I were literally out in the field, hopefully with the solar panel bolstering, if not compensating for the drain caused by the nano-ITX device, the battery life would be prolonged to last a full day. The MP3450 can be expanded to have a second battery spinal-tapped into it, doubling its capacity, so likely I’d start with a 3450, and add on the extra battery pack if it seems it was needed.
The final hurdle would be an operational one: the FrogPad is designed to be a keyboard replacement, but not a mouse replacement. If a good set of keyboard commands were set up to launch applications, move between applications, and set focus to various fields on the screen, that would be sufficient, or if Xfce has something equivilant to the Windows “MouseKeys”, where you can move the mouse with your arrow keys (designed for the physically handicapped, but useful if you don’t have a mouse, as well). I’d likely stow a USB mouse in the bag for the times I would be sitting down to be able to get more fine-grained control.
So that’s my plan. I don’t have the funding, nor all the pieces yet, but I’ve at least got all my links in one place here in this post now. Probably a first step is to get a FrogPad for use with my standard desktop to see if I like it enough to continue using it on a mobile system. Then outfitting the messenger bag with the solar power system, such that it could keep my smaller electronics charged, and test out that system, before launching into the computer melded into the bag.
I did some more work on my previous calculations and arrived at a slightly depressing result. I did eventually find the spec sheet for the Tekkeon battery, and found that it is designed to hold 50 watt-hours of power. With a little math, that equates to 180,000 joules of energy stored in the battery. A nano-ITX-sized computer would likely draw around 12 watts of power, or 12 joules per second usage. This means a full Tekkeon battery would charge it for a little over 4 hours. Not bad, but in order to get through the whole day without recharging, I’d have to get the expansion pack to double the capacity. On the truly bad side is the solar charging. The Solarfilm panel that would fit my bag is only generating 1.5 joules/second optimally. That means it would take over 30 hours to charge the tekkeon, and would only expand the life of the battery by 14% if it was charging while the computer was draining. A more likely solution may be a Powerfilm panel that’s twice as big as my bag (and would be set up as a flip-down flap that could lay out in the sun to charge, or velcro/clasp closed to travel) that outputs 4.62 joules/second. That would charge the battery from empty in only 11 hours, and if run at the same time as the computer, would make it last 6 3/4 hours (63% increase).
