Automatic Stair light display

Hi, Im in the early stages of wanting to design a light display thats activated as you go up or down the stairs, lighting the stairs as you go. I have search this and found so much information that I just want clarification on a few things if possible.

I have 12 stairs so 12 LED's. I would like then to come on as a chase sequence up or down, with each LED fading up to full brightness then fading out.

My questions are: Would the Uno Rev3 board be sortable allowing the fading up and down to take place, also I'm thinking of using shift registers, can the fading still be carried out through the registers?

Not looked into trigger sensors yet or types of LED's but was wondering are all LED's dimmable. Was just going to order some of eBay.

Thanks in anticipation.

the UNO will have much more power than you need. lots of room.

if you want to light more steps, you can all a shift register. this uses 4 pins but adding one register adds 8 outputs. adding a second adds another 8 but still only uses the same 4 pins. you can add a third and still use on the original 4 pins.

there was some discussion about using a motion sensor at the top and bottom and adding a distance sensor to test if the person stopped and went back down.

also the idea of one beam break on each step could allow you to know what step is being used. and what direction the person is moving.

Leds don't fade but can be turned on and off so quickly the brightness can be controlled.
One of the earlt Example sketches in your IDE shows a way to do that. Not the best way but the easiest.

You will need to sense people on the stairs. There's probably a dozen ways to do that. You might even use more than one way just to be sure.

Make sure the fade doesn't take longer than someone will move. Not everyone walks slow on stairs.

Maybe you even want to know if the stairs are well lighted or not? Day/night, overhead lights?

Thanks for explaining the method of fading LED's, will order my board tomorrow and start learning the code etc.

Any ideas on 5mm or 10mm white LED's on eBay, theres so many on there. Need them bright as only using 1 LED per stair fitted in the stringer shining across the carpet.

I got like 5 5mm bright RGB leds for $1 from Yourduino... well I got more like 50 but that was the deal. The thing is with the shipping, I bought a lot of resistors, transistors and chips at so many per $1. At those rates, I don't bitch about the shipping once the total goes over $20. And they have far better support than DX.com or eBay! More like what you'd expect at Sparkfun and Lady Ada so I know where to look to use what I bought.

RGB 3 colors in 1 led that can easily do 24 bit color with 8 bit PWM. Would you like to use colored light?

The white is high bright, all 3 elements on full but maybe you want a tone with just a bit less blue and more red?
You could reflect led light off the ceiling, walls and stairs using more than just 1 led per stair.
Put leds along the ceiling as well as lower and let the walls and ceiling reflect light to cut shadows.
You could make like sunrise ahead and sunset behind, or lamplight, try and keep the subject in between.

You can run them with shift registers not just to multiply pins but to distribute external power and ground, and do that using 4 pins and change them all individually faster than you can see.

And you are very much going to need a system that can respond to events, including time like a state machine.

GoForSmoke:
I got like 5 5mm bright RGB leds for $1 from Yourduino... well I got more like 50 but that was the deal. The thing is with the shipping, I bought a lot of resistors, transistors and chips at so many per $1. At those rates, I don't bitch about the shipping once the total goes over $20. And they have far better support than DX.com or eBay! More like what you'd expect at Sparkfun and Lady Ada so I know where to look to use what I bought.

RGB 3 colors in 1 led that can easily do 24 bit color with 8 bit PWM. Would you like to use colored light?

The white is high bright, all 3 elements on full but maybe you want a tone with just a bit less blue and more red?
You could reflect led light off the ceiling, walls and stairs using more than just 1 led per stair.
Put leds along the ceiling as well as lower and let the walls and ceiling reflect light to cut shadows.
You could make like sunrise ahead and sunset behind, or lamplight, try and keep the subject in between.

You can run them with shift registers not just to multiply pins but to distribute external power and ground, and do that using 4 pins and change them all individually faster than you can see.

And you are very much going to need a system that can respond to events, including time like a state machine.

That sounds nice, I like the idea of colour but I feel for a newbie, could be complicated. Wouldn't know where to start to control the colour.

Just a couple thoughts. What to the lights do when the person changes direction mid-way up? Can you handle more than one person on the stairs?

MrsCrossRoads:
Just a couple thoughts. What to the lights do when the person changes direction mid-way up? Can you handle more than one person on the stairs?

Not thought of that one, probable allow LED's to stay on longer before fading out. Cant think of any other way.

You control color by adjusting red, green and blue levels.
It's usual for white leds to be more blue than sunlight, they look more like moonlight.

In this application (including one of my own) the TLC5940, controlled by a controller such as an Arduino, is often used. It is ideal for your application and may nicely enhance your project. - Scotty