Hi Joost, my tablets currently looking like this(right click to view image to see bigger size):
I have USB charger behind, and tablets are fixed on magnetic holders, used for fire alarm sensors. The USB connector is from wireless charger - they are quite small and have 90° angle.
PS to make it clear - I dont have wireless charging. I have created a USB cable using this:
buy wireless charger (available on ebay for few bucks). Be sure to select right connector and angle direction - they can be inverted.
And then cut the connector from it and solder it on standard USB to receive following cable(be aware not to mess the polarity as it is printed wrong on charger):
It’s flat and with right connector angle and almost invisible. Would be great to get such cable ready-made, but where those Chinese guys, when you need them most?
Then I used Apple A1385 USB charger to put it into wall, as it has M3 holes on end, is really, really small, reliable and has worldwide voltage range - this charger is art of engineering in my mind - genius Apple.
So you get following picture (yes, Apple charger is all there. Do you see it?)
And finally applied magnetic holders above and below wall opening. Some cutting was needed as 7" tablet is too small. Don’t throw away those cuts, as you will need them! So the construction behind tablet looks as follows :
Glue the counter-pieces on the tablet and you’re almost done. There is one trick. If you don’t do it, the tablet will slide down on those magnets. So what you will need is to glue the cutted piece on top of the lower counter-part, so that it would hook over lower wall magnet piece. Then tablet will not slide down anymore and will stay there bombenfest.