Hi, I am looking for a simple way to light up a WS2812b LED strip.
I got the strip from a ambilight project on kickstarter and have ~1m left.
I want to use it to light up my christmas tree.
I do not need to controll anything it is fine if it just lights up white.
I would like to use a 5V 2A usb charger to power it.
I do not need to adjust anything.
I already connected positive and negative with a usb cable but it lights up just for a second.
the strip needs 12 Volt i assume your powwer supply switches off- 
-i ordered these to play with: DC-DC stepup converter
i was corrected…
Actually 2812b is 5V. Data sheet says “…after the pixel power-on reset, the DIN port receive data from controller…”. My understanding is strip won’t stay lit unless it is told how by the controller. And even if it did default to 255/255/255 aka full brightness white (which is only default that makes sense to me), LEDs without any heatsinking wouldn’t take it for too long. I think cheapest option is to get $2 Arduino clone from Aliexpress and use one of numerous code examples to drive the strip. Since all Arduino hardware is open source, clone in this context doesn’t imply low quality or reliability, it’s the same thing as $20+ hardware.
Ok thanks, yes it needs 5V.
Can you please point me to a clone that would work with this strip?
Would this be ok?
What about this?
Yes, those look good. I would go for a smaller board (both are Atmel 328p based) since you don’t need barrel jack for power, it can be powered directly on pins, and you probably already have bunch of micro usb cables (only needed for flashing).
Here is an even cheaper one from seller with thousands of transactions, with free shipping, of course.
Ok thanks, I ordered the nano version. Do you have a good tutorial for the nano version?
I found this tutorial but it uses a uno Tweaking4All.com - Arduino - Controlling a WS2812 LED strand with NeoPixel or FastLED
That tutorial still applies. Ideally you will only need to change the definition of a data pin.
If some additional changes should be necessary, think of it as a fun challenge. 
I should be getting some 2812 strip soon (ordered month ago), so I will be able to help you set everything up.
Great, I will report back after I have the controller in my hands. I will following that tutorial and see what I can achieve
AdaFruit has a guide for people who are new to individually controlled led pixel strips. Read through the page I linked and follow the rabbit hole for a little while. There is tons of information there.
Thanks this looks very helpful!