What Is a LED stairs controller?
The video shows how it works!
Step 1: The idea
The main idea was taken from Alan's Parekh video, many thanks to him.
The idea was this: When I get up at the middle of the night to get some food, I have to go down the stairs from the top floor and then up the stairs again. One day I've decided I need an automatic backlight so I don't turn all the lights on and wake my family up. Plus I wanted a nice smooth turning on and off so it doesn't irritate sleepy eyes. Also the device had to be error-resistand, ignore sunlight, remotes and other things.
And so in order.
Step 2: Electronic components
The heart of the controller is an atmega16a-pu chip which has a lot of outputs.
As for load control (12V 1W or more), I've used transisters 2sc2655 as they are powerful enought for what I needed.
For LCD i'm use LCD 16x2 (HD44780 chip)
The sensors I first thought to use was version of the IR lED and IR Transistor, but the distance within it's sight could not get more than 1 meter, so it was decided to use TSOP1838 + Modulation 38kHz .
To power this all up I've used the converter LM7805 + Heat Sink.
Resistors and capacitors you can see on the motherboard of the device.