|Re: Does it really have to have keys?|
Message #5 Posted by DaveJ on 19 Sept 2011, 9:03 p.m.,
in response to message #4 by Oliver Unter Ecker
That's an interesting aspect I hadn't known about. Any ideas how the nook can still offer two months claimed battery life? (I don't think they completely exaggerating because they'd be called out for that, as enough people compare it to the touchscreen-less Kindle, which claims a month and does 2 weeks.) Might the digitizer enter a drawing-almost-no-power mode, while not tracking?
The usual resistive touch screens take significant power all the time. Although you could shut them off under software control.
Maybe some form of capacitive touch screen instead, I'd have to investigate.
Are there SoCs that include the necessary logic to drive/read a touchscreen? (I imagine there are.)
Some I believe, but in any case it's fairly trivial to add capability.
But designing such a hardware platform would not be too hard. I'd imagine a thin machined aluminium case with a screw on front cover to hold all the guts in, an ultra thin rechargable lithium poylmer battery with micro USB connector for charging, and maybe a micro SD card slot.
Yes, lovely. Your comment that it wouldn't be too hard is intriguing.
It shouldn't be, I've gone through the motions with my calc watch projects.
It's just a matter of getting a suitably thin case machined.
Such a design would slip in a shirt pocket real easily, and would not be that hard to prototype into a really usable form I suspect.
Could you quantify this somewhat? What do you think it would take in dollars and time to get to prototype and final HW stage for an aluminum-clad touchscreen ARM SoC-based thing, with a micro USB (and maybe micro SD) and sole power button? (Very rough estimate to give me a ballpark idea would be much appreciated.)
I can give you a reasonably accurate ballpark.
Rather than guess, I did a quick case design in eMachine shop, and the price comes out at $265 for 10 cases custom machined in 6063 aluminium, not including a backing panel. Includes shipping to Australia. $175 without shipping.
But that is a crude model, lets up that to say $300 for a more refined one with tapped holes for the backing panel, clear annodised etc.
The PCB would cost about $150 from pcbcart.com, cheaper from someone like iTead Studious, as little as $50.
The LCD screen would cost a bit, I don't have a price on the 3" model, but the 6" model is $200 from Mouser, so let's guess $150 that.
Other parts, let's say $50.
Battery from PowerStream.net come in thicknesses down to 0.5mm. But the 303040 model is 3mm thick 320mAh one costs $10.
Touch screen I don't know yet, haven't looked.
Time wise, a couple of days to select components and lay out the PCB, another day or two to design the case. You wait a month for the case prototype, but quicker if you knew someone with a suitable CNC machine. A day to assemble, and then another day to get a hello world running.
So really, apart from lead times, I estimate I could get a prototype working with 1 weeks worth of work, and under $700. That is fairly accurate because I've done the same thing before with the uWatch and uWatch projects, only difference is they didn't have the custom case.
The case I have shown is close to actual size of 45mm x 80mm x 5mm thick for the 3" display (not including backing plate). Actual thickness I'd need to tweak depending upon various available parts. The LCD itself is less than 1mm thick.
This isn't pie-in-the-sky stuff, those are real figures. The only unknown for me is how well someone like eMachineshop can machine such an aluminium case.
Edited: 19 Sept 2011, 9:29 p.m.