Suggestions for wall mount displays

[Linwood]

Any suggestions for wall mount displays for (mostly) permanent mount?

I've considered something like a generic android, in some kind of a mount. Will need to get a brick into the wall somewhere. That may be where I end up.

Had also looked briefly at touch screens. There are a bunch out there now in the circa $100 range that are decently big and (I think) i could drive them with a raspberry pi, though I am not quite sure how (a real linux gui on a pi?).

I think the days of thin clients (i.e. purpose built browsers-as-hardware) seems to have passed, I did not see any cheap ones of those.

I am a bit worried about horse power, as I have 7 high res cameras.

No audio, but might like to add audio and one more camera for a door announcer, one day, maybe.

My desire is a monitor that can go to sleep, wake up on touch and (still be or start) showing a montage view and generally allow web browsing. Low power and cheap preferably, as I would like to have at least two if not three. And big enough that fingers can navigate.

Has anyone done this and care to share real world experience?

[Fatman]

I use a wall mounted iPad for this purpose

[Linwood]

Thanks, Fatman, what did you do for power? I've been looking and ipads seem a bit picky about how they are powered. I was going to run +5V to it through a long wire (actually the wire is already there for an old door intercom I removed), but not completely sure if it will work out. I don't want wires hanging down to nearby outlets.

[mikb]

Don't run 5v through long or thin wires, it won't be 5v when it gets to the other end due to losses. Whether you run out of voltage tolerance will depend on the device, and how much current it draws

[Linwood]

Suggestions?

I thought about mounting an outlet IN the wall, but I'm not sure that is permitted by code (I have read that it is not, but have not tried to look it up yet -- plus this wall is outside next to block and I don't think has the usual depth).

I've got 24 guage stranded copper running about 25' to a closet, this was providing power to an old video system. Because it's easy -- just need to splice into a USB cable ends -- I think I may give it a try and measure the voltage that results, if it works at all. None of my other options are pretty. I don't mind being a bit of a hack with low voltage, but I want to keep the AC fully up to code. I'll look and see if there are some legit forms of recessed outlets, perhaps, that could still allow a power adapter to be plugged in.

Unfortunately the wire there now is stapled in the wall so I can't use it as a pull, and there are numerous horizontal blocks in that wall (I've tried fishing down from above and up from the middle -- and it's 14' up), so running new cable is an ugly option. I'd hate to open up all that sheet rock, as it is right beside our front door and my wife can get real mean when my hobbies screw up the main living area.

[Linwood]

Well, just in case anyone else decides to try -- the straightforward attempt did not work. Took a USB extension, spliced it into the existing wire and plugged into a real Aplle adapter. It flashes briefly like it might charge then says "cannot be charged with this accessory". I'm not sure the voltage is accurate at that point as I think it stops drawing current, but it shows 5.1v at the iPad end. My guess is it is substantially lower.

Not so straightforward would be to double up the wires to get less resistance in the power side, but that means (if I recall) building some kind of resistor bridge to tell the iPad this is an OK power source. I might try that, but am more looking for alternatives, and none are attractive. I looked at going through studs to the nearest outlet, but it's either 3 or 4, so LOTS of mess to open holes beside all those. Probably better to pull out the molding and work down there, but also pretty messy.

I wonder how long a 6V alarm battery stuffed in the wall would power it. If I could pull out a wire once a month and charge for a few hours... but I suspect it would not last that long.

I suspect it's code, but I sure wish that in new constructions they would not stable low voltage wires in walls, I cannot count how many times I've wanted to pull some different wire back up.

[mikb]

Suggestions?

For 5V at destination, send 12v from source. Bring 12v down to 5v the dumb/cheap/inefficient way with a 7805 regulator, or something much smarter like

http://www.ebay.co.uk/itm/7V-24V-to-5V- ... 4179d0059e

It trades the excess voltage for reduced current. Meaning that your 5V at (whatever) amps is going to be less than half the current at 12v. You win two ways: Losses in the cable reduced, guaranteed 5v at the other end.

You may have to fiddle about with the "sense" resistors if Apple are being funny about requiring this ... as you've already found. The approved charger will provide 5v and tie the data lines up/down as expected.

I'm using these modules to power IP Cameras at distance (17v approx sent) over cat-5 (ghetto power-over-ethernet) and to buck 23v down to 5v for a raspberry pi/HDMI display. They are slightly hackable to add a low voltage cutout, a low-power "suspend" mode, and to tweak the output voltage up and down a bit.

[Linwood]

Looks like a real possibility. Are the data lines exposed on the board somewhere that would be easy to splice into with the resister set needed? Or am I going to need to separately build that into the cable that plugs into this?

I was just about to cover up this hole and do something different, like find a slanted stand and put on a table beside the door.

[mikb]

Looks like a real possibility. Are the data lines exposed on the board somewhere that would be easy to splice into with the resister set needed? Or am I going to need to separately build that into the cable that plugs into this?

I was just about to cover up this hole and do something different, like find a slanted stand and put on a table beside the door.

Data lines are brought to pads right near the USB connector

http://img.dxcdn.com/productimages/sku_144860_3.jpg

which allows possibility for SMD resistors to pull up/down etc. -- I didn't need this as I just wanted 5v, generically

[Linwood]

Thank you.