Animated effects for a LED illuminated staircase.

Hi,

I would like to illuminate my staircase with LED strips. I plan to install a strip on each stair and do some animated effects with the help of na Arduino type board based and motion sensor installed at the top and bottom of the staircase. For exemple I would like the strips to illuminates sequentially from bottom to top of the staircase, or the other way around depending which motion sensor detects a person.
The easiest way to achieve it is a series of relays controlled by the board. But I would like also to be able to dim the LEDs to control the amount of light they give. I have some doubts how to achieve it:
An easy setup would be to have a 12V power supply connected to a LED dimmer and then the relays to each of the LED strips. But I'm not sure if the LED dimmer will work well when there are relays between it and the LEDs. Has anyone some experience with it?
Also, do you know a LED dimmer that can be controlled by an Arduino board?
In addition, a nice effect would be an fade-in/fade-out effect for each strip, but I don't know if this is easy to make.

Also, do you know a LED dimmer that can be controlled by an Arduino board?

It depends on the dimmer’s circuit. But the Arduino can act as a dimmer.

What sort of LEDs? Fixed colour, all the same colour or programmable colour?

What sort of anamation, on / off, individual control of LEDs?

How many stairs?

It seems to me that the easiest way to achieve this would be to use ws2811 or ws2812b strips or similar. No relays or dimmers needed.

Grumpy_Mike:
It depends on the dimmer’s circuit. But the Arduino can act as a dimmer.

What sort of LEDs? Fixed colour, all the same colour or programmable colour?

What sort of anamation, on / off, individual control of LEDs?

How many stairs?

I have 18 stairs. Each led strip will take 0,3-0,5 A, so in total it will be 5-10A. I don't think Arduino itself can handle that directly.

Correct, that is far too much current for the Arduino to handle. But using ws2811/ws2812b leds, it would not have to.

froggykk:
Each led strip will take 0,3-0,5 A

How many leds per stair?

PaulRB:
It seems to me that the easiest way to achieve this would be to use ws2811 or ws2812b strips or similar. No relays or dimmers needed.

Thanks, this is a good idea.