Powering controller (NodeMCU) with USB

Hardware
1

I’m hoping to connect 2 strips of WS2812B or SK82112’s and having an electrician give his recommendations about wiring them on an outdoor patio.

I’m wondering if I can power the controller through USB then provide the power to the lights through 1 or 2 power supplies.

Right now I have it wired with power supply to 1) Red/Black on one LED strip and 2) Red/Green/Black to Vin/D4/Ground on controller - This works and seems to be the most common way of wiring

Would simply removing Red and Black from 2) and
Controller D4 => data (Green) on strips work?

Then injecting power at the beginning and end of each strip

2

You would have to connect the grounds of all supplies together.

3

Can that be done through the ground in the LED or would a separate line need to be run?

USB => controller

Power supply 1
Controller (Ground pin)
Strip 1 start (5V & G)

Power supply 2
Strip 1 end (5V & G)
Strip 2 start (5V & G)
Strip 2 end (5V & G)

4

No, just connect up the black and green lines. Do NOT connect the red 5v together as that will damage your power supply.

5

So if I’m still using the JST connectors between LED strip 1 and LED strip 2, sever the red 5V between the two of them. Use the red and black from the power supply into the other power injection wires.

The ground will be tied together through the LED’s themselves and the B in the JST connector

1 Like
6

I am interested why you would want to power the controller from a separate source from the strips. I use an LM1117t regulator between the 12 volt power on my pixels and the ESP8266. This seems to work well and is easy to solder to the 8266 and the connector.

7

Really just trying to brainstorm ways to keep components dry in an outdoor installation

8

If just keeping the controller dry is your primary goal, I found it easiest to just solder on the JST 3-pin connector and powering the NodeMCU from the LEDs. You will need to waterproof the GND and DATA lines between controller and LEDs anyways so the extra 5V wire is easier than a whole extra power supply for the nodemcu. The exception would of course be if you plan to switch the 5v to the LEDs with a relay to save the standby current they use (1mA per LED when set to off)