So, it works, that is the main thing. The next steps to take are:
It has worked reasonably well so far. The photos do not show the LED wash very well. The only issue i have so far is that it is just not bright enough. I will try some 60 LED/metre strips sometime.
So, this is what it looks like with the main room light turned on..
..and this is with the light turned off....cool, that makes it worth it for me.
After testing the basic capacitive basic touch sensing, i decided just to use buttons for the time being.
For the initial testing i use pins to attach a piece of white cloth over the frame, this will be replaced later with strips of velco so that the cloth sits nicely inside the frame.
The first basic circuit design contains the Arduino Pro Mini, LED strip output, buttons and a basic attempt at capacitive sensing.
( for the software please browse my Github repository )
Again for the brain, the Arduino Pro Mini is used. This development board is cheap and has enough juice to do what is needed, which is:
A piece of stripboard will be used for the basis of a small circuit. The Arduino also attached to this board, and is programmed via an external FTDI board with USB.
The power supply used is 240v -> 5v regulated (with 2A max draw, more thab enough for the amount of LEDs i will be running). Power from the transformer then is fed to two lines on the board.
It is then tapped straight away to feed the Arduino, which passes on power to switches and sensors. This helps keep the ground lines stable.
After the tap a 1000uF capacitor is placed across the main power lines. This helps absorb any surges at startup and thus protect the LED strips.
..speaking of LED strips.. remember this..
they will blow as they have no reverse current protection..!!!
anyway, where was I... ah yes..
After the 1000uF capacitor, power is then taken for the LED strips themselves. Two power cables are joined with a data cable in a JST plug, the adjoining part leading to the LED strips.
The desk is a quick straight framed knock-up. Cheap timber and the side from a wardrobe gives me a useable long desk in the corner of a room. The desk has a window to the left of it, but only gets a lot of light during the morning (direct only in the summer). The frame to the right of the desk is for storage baskets. LED strips are to be placed around the inside of the nearest parts of the frame, with a cover to diffuse the light. The electrical components will be housed on a shelf underneath the end of the desk.