Two weeks ago I've finished a LED-Strip based Steplight for friends of mine.
It's based on a standalone Atmega328 running at 16MHz driving 2 ULN2803A for the 14 LED-Strips. The complete installation is driven by a 9V / 1A powersupply, consuming only 600mA with all LEDs at 100%. The trick is to drive 12V LED-Strips with only 9V, reducing the power consumption dramatically. The reduced brightness is not a problem, the LEDs are still “too” bright and have to be dimmed.
The 5V for the Atmega are provided by a L7805 voltage regulator. The µC uses the Arduino bootloader and gets the sketches from a FTDI-breakout that can be connected to a 6-pin pin-header.
The PCB is placed in a small box mounted on the wall under the stairway. Two IR distance sensors are place on the top and the bottom steps to recognize persons going up and down. The direction of the "moving" light depends on the direction you are going ( up / down). The speed of the moving light, the maximum brightness of the LEDs and the "light is on" duration can be adjusted with 3 15k potentiometers on the control-box.
I've made a small video with some pictures taken during the creation and two “how it works” videos.