On Saturday 10 December 2011 02:01:51 Luke Kenneth Casson Leighton wrote: > batteries / power. ah. when you say "digital photo frame", do you > mean "portable device" or do you mean "put it on the wall or > mantlepiece"?
I mean always on power socket. No batteries > > Then, we'd need to field test our device. This could be done with > > netbooks or small tablets, but not with a bunch of boards and wires ;-) > > . We'd need ~ 10 of them to lend to family and neighbours and get > > feedbacks. > > ok, well we have about 17 committed so far. the hardware development > costs (PCB, tooling) are about $USD 2,000. with 10 more, that would > be about $75 each for one (fully-populated, fully-functional but with > no external case) CPU card. This thread started on tablet hardware. Do you have a price range for such a device ? (i.e. with screen and case) > an overlay resistive touchscreen is about $5, typically. they do > however require calibration: they're also sensitive to temperature, > humidity etc. ok I've seen this kind of device while repairing my kid's gameboy. > capacitive ones made of glass are *MORE* expensive than the > same-sized LCD! absolutely ridiculous, but that's the way it goes. > they're also heavier (because they have to be structurally strong). > there do exist plastic capacitive touchpanels, they're still in > development, the price _will_ come down... at some point. ok let's forget these. > bottom line is: touchscreens sound great until you look into the cost > and useability. The alternative is a remote control. Generic ones are used to navigate in menus. But this is not user friendly for older people. I'm thinking about having a more specific remote control, but I'm worried about the development cost (PCB, plastic molds...) > there are some options however for very coarse-grained touchscreens. > if you can get away with "button-sized" fixed areas (such as used on > microwave ovens) then costs are dramatically reduced. I guess that such buttons could be drawn on the screen when required. One touch anywhere will trigger drawing buttons on screen. > fortunately, electrons haven't changed charge or anything like that: > the speed of light is still the same constant, as best we are aware, > and V still equals I times R :) ;-) All the best Dominique -- http://config-model.wiki.sourceforge.net/ -o- http://search.cpan.org/~ddumont/ http://www.ohloh.net/accounts/ddumont -o- http://ddumont.wordpress.com/ -- To UNSUBSCRIBE, email to debian-arm-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/201112131353.05346....@debian.org
