LED-Strip Stairs Project. General help.

Projects General Guidance
1

Hi,

I am thinking about installing LED-strips in my stairs, with a motion detector on the top and bottom.

I have currently landed on using the Adafruit NeoPixel Digital RGB LED Strip - White 30 LED. That gives me this:

  • 15 steps
  • 0.75m LED pr step.
  • 9.5W pr meter LED strip(from Adafruid)

Which gives:

  • 9,5*0,75=7,12 W/step

  • 7,12W*15 Steps = 106,8W total.

  • 106.8W / 5.0V = 21,36A.

I have made some code, that as far as I can tell, works. I have tested on single leds on a breadboard.

What I do need help with, is tips on what kind of power supply and what kind of motion detector I can use.

I am thinking a 20 - 25 A power supply will do fine as the 9,5W pr meter led is full white, and I will probably have them dimmer than that anyways. I don't want to buy a crappy one that will catch fire, and I don't want to over spend on something I don't need.

The same goes for the motion detector.

I really don't have any experience with the equipment so I would love someone to share their thoughts :slight_smile: And also any tips and tricks on this kind of project is more than welcome.

Thanks,

Thomas

2

That's a decent amount of current. As you already calculated, a 20A supply is to low. You say you will dim it but if you accidentally turn it on full you overload the supply. 25A seems better.

But be aware 20A takes pretty beefy cables. I would say 8mm2 or 10mm2 at least. Because those pixels really don't like a low voltage (and 0,5V already is 10%!). So maybe multiple wire of more manageable 2,5mm2 is more convenient.

As far as the detector goes, some options:

  1. PIR-sensor
  2. Switch under the stairs
  3. Piezo under the stairs (acts as a knock sensor)
  4. IR-beam across stairs
3

Thanks for the reply. I am aware of the current and cable mm^2, so hopefully that wont give me any problems, what I do need tho is some examples of descent power supplies. I have no experience with this, so Id like to not buy... Well crap :slight_smile: