On Tue, Dec 13, 2011 at 12:53 PM, Dominique Dumont <d...@debian.org> wrote: > 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
whewww :) > This thread started on tablet hardware. Do you have a price range for such a > device ? (i.e. with screen and case) achh... mass-volume pricing? 7in 800x480 LCDs are around $12, a case would be around... $2 if that. motherboard (in this instance) 2-layer single-sided including components: probably about... $2.50. bits from the EOMA-PCMCIA card: about $15 - total comes to about $30 to $35. it's the lack of a battery (in this instance) that does it (normally an extra $6 to $10 or so). non-mass-volume pricing would approximately double things. profit, tax, shipping etc. usually adds at least 100% on top. >> 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. achh, pffh, if you've handled those, you're onto a winner - you know the score. btw you can actually get 7in LCDs which have resistive touchpanels already attached. >> 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...) the PCB is peanuts. the circuit's simple enough to use a breadboard. i think... you _may_ get away with an LCD Driver IC that has legs (DIP) - can't remember the name of the one that's so low-cost that everyone keeps using it, even though it's not SMT, it does voltage-multiplying up to 28v, for arrays of LED backlights.... achh, apologies. you do _not_ want to go down the route of having your own case manufactured. find a box that is "close enough", or spend vast amounts of time finding something off-the-shelf. despite spending vast amounts of time, it is guaranteed to be less money than paying to have a case developed. if you do not believe this, please review the openpandora blogs. another option for low-volume is acrylic (which is clear), then paint it. specialcomp got a case designed that way for the beagleboard. >> 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. yes - and if you keep it coarse-grained enough, you shouldn't need to do too much in the way of calibration of the resistive touchpanel. calibration is only kinda needed if you want millimetre / centimetre accuracy. if you only care about "the top quadrant" you're laughing. l. -- 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/CAPweEDwy-+Hmw2pdYjo7qjL0_ChCgihhG=9r44gvybw4fgc...@mail.gmail.com
