Transfer data with light?
Have a look at this TED talk by Harald Haas about wireless data from every light bulb.
I think that type of data transfer could be made with just the screen and the front camera. All it takes is an app to do it. The hardware is there.
Maybe there could be modes for different distances? A fast mode for the phone in the next seat on the bus. A slow mode for outdoor messaging? An emergency MayDay mode too, perhaps?
(This idea is called darkMess and is part of the Jolla Helm suggestion for the second device hardware thread. Also used in the sailfish car mode UI thread.)
Saw the Goccia activity tracker at Slashgear and it uses light to transfer data from the device.
One ways Goccia is able to last so long on a charge despite its small size is that it uses LED light sync technology. To synchronize data with the app on the iPhone or iPad, you need to place the Goccia on the front camera of the device and tap it to start synchronization.
http://www.slashgear.com/goccia-multi-sport-activity-tracker-is-the-size-of-a-dime-21325914/
Find-Your-Friend
My Nokia Blog has posted an article about a Windows Phone app called Over Here that cleverly uses light in a simple manner. Not much data is transmitted but enough of it.
http://mynokiablog.com/2014/05/19/over-here-helps-find-friends-in-a-crowd/
We could have tried something similar at a concert last week, but thought about the flashlight too late. The flashlight would be strong enough even with full lights inside the arena.
2015-02-13
Now for android too... http://www.engadget.com/2015/02/12/lookfor-flashing-lights/
Update
Lifi can be received with an off-the-shelf solar panel.
http://www.ted.com/talks/harald_haas_a_breakthrough_new_kind_of_wireless_internet
Promoting to skunkworks..
Stskeeps ( 2014-02-15 22:34:56 +0200 )editJolla phone2 with Wysips Crystal + LiFi integrated, a must have, cream of cream thin layer transparent solar charger (allow reduce 20% battery size , self-sufficient + led communication.
So far better before other brand/device if exist on Jolla phone/SailfishOS http://www.youtube.com/watch?v=DFUCX6Wb5Lg
redge73 ( 2014-03-12 04:32:59 +0200 )edit=> http://desguin.net/spip/local/cache-vignettes/L600xH412_Lightbulbs_Could_Replace_WiFi_Hotpsots_1-5a239.png
objectifnul ( 2015-11-05 22:00:42 +0200 )edit