Arduino Nano and WS2812B adressable leds.

Other Hardware LEDs and Multiplexing
1

Hello everyone!
For my project of custom HTPC case, I would like to add a bit of lighting.
I planned to use adressable LEDs with this strip. For my case, I will use 25cm of this strip, so 72leds.

As I presented it and asked for help here: SSD1322 OLED Display and Arduino Nano - Asking for help from A to Z - Displays - Arduino Forum , I will also have a OLED screen connected to the Arduino Nano.

I think I won't be able to connect the strip directly to the board so what would be the wiring needed?
If needed, I have molex cable unused (so a 5V power source). The Nano will only be powered by USB.

Thanks for your help,
Nicolas

2

I think I won't be able to connect the strip directly to the board

Yes you will.

3

you should put a 220ohm resistor between the pin you choose to drive the strip and the data in of the strip

4

Thanks for your answers!
I wanted to follow this tutorial and it says each led draws 50mA. My arduino will have to supply 3.6A on the 5V pin, and I don't even count the OLED screen and the level shifter I need for it.

Regarding that my arduino nano is only connected to a USB port, I don't think the board can handle it.

I can connect the ground and 5V to the molex cable I have left in the case, but what about the data input? Can I connect it directly (or with the resistor) to a pin of the board or do I need some component between?

Thanks,
Nicolas

5

"My arduino will have to supply 3.6A on the 5V pin,"
and we all know that is not possible.

Get a 5V, 4A supply.
http://www.mpja.com/5-Volt-DC-Plug-Power-Supply-4A-Regulated/productinfo/18520+PS/

and a connector if you don't want to cut the end of the power cord off:
http://www.mpja.com/55mm-OD21mm-ID-Chassis-Power-Connector/productinfo/18549+PL/

This one comes with micro-USB B adapter cable. Not really a help to you, but nice to know it exists.
http://www.mpja.com/Raspberry-Pi-4A-Power-Supply-and-Adapter-Cable/productinfo/32498+PS

6

Thanks for your answer!
As the board will be installed inside a computer case, I would rather not use a external power supply.
As I said, I have access to the 5V molex rail with a capacity of 11A.
My question is, should I connect it to the board or directly to the led strip? I am using the basic jumper cables, isn't dangerous considering the high amperage?

7

Suggest you fuse the line.
Also, make these connections:

800×469 135 KB

8

It's exactly the scheme I was looking for, thanks!