NodeMCU LED strip

Newbie here to NodeMCUs. I’ve had one in a drawer for a long time but never put it to use - decided that I’d change that by having it drive an LED strip (following this info

I’m powering the board via USB with a 5V/1A wall socket, but I’m finding that after a few minutes the board starts to smell as if it’s too hot - this is the first time it’s been powered on and I’m not sure if that’s why or if there’s a problem with it. Any experience welcome!

Secondly, controlling the strip works fine, however I’ve noticed that the closer I set the colour to white, the more you can see a colour difference along the strip (it’s a 5M/150LED strip). It starts off birhgt white but the far end of the strip ends up a strong orange. This is apparent with other colours when the colour strength is turned down, but doesn’t seem to be as obvious with the green and blue side of the spectrum. Does this sound like a dodgy strip?

Wow. You need to disconnect that right now. A 150LED strip CANNOT be powered by a 1amp power supply. You probably need somewhere around 10 amps at least. And I hope you didn’t connect it to the NodeMCU. The strip should be directly connected to the power supply and the NodeMCU connecting to the power supply as well. I don’t think the pins on the NodeMCU are designed to be able to push multiple amps through them. That might be the burning you are smelling.

I’m planning on doing a write up on how to hook something like this up.

Right, that would certainly explain my issue! I had a feeling that reddit post just made things look far too simple if i’m honest - it seems quite hard to find a concrete write-up on doing this. So to make this work i’ll need a PSU to power the strip with too (it has separate wires for feeding power in)

It does take understanding the requirement and safety of building electronic devices.

5V LED strips are going to require more amperage and potentially a power tap in the middle of the strip (300 LED 5V strip at full brightness) due to voltage drop that can occur over the length of the strip.

Example of strip I have used:

ALITOVE 16.4ft WS2812B Individually Addressable LED Strip Light 5050 RGB SMD 150 Pixels Dream Color Waterproof IP67 Black PCB 5V DC

5 Meters at 9 Watts per Meter = 45W Total

Watts Law
45 Watts = 5 Volts * ? Amps
45 Watts / 5 Volts = 9 Amps

Now that is just the calculation for the strip without accounting needs of the NodeMCU. The NodeMCU uses at most 1W and that is a high estimate based on a quick search. At 1W you are looking at 0.2 Amps @ 5V, without going into detail of the power usage of the device, this is probably a fair value to use for sizing in this case. So, 9 Amps (LED Strip) plus 0.2 Amps (NodeMCU) you have 9.2 Amps, so the suggested 10 Amp power supply is enough with a safe overhead.

The LED strip will need to be connected directly to the power supply and potentially to both ends depending on the length if you want to go full brightness. Connect the NodeMCU VIN pin to the power supply, but DO NOT connect VIN pin to 5V power supply while you have the USB connected from your computer, you can and probably will destroy your USB port on the computer. For testing/programming, you can have the USB connected and the 5V power supply connected to the LED strip as long as you connect the Ground/Negative (black wire typically) to the NodeMCU and the LED strip and DO NOT CONNECT the VIN pin on the NodeMCU (see previous warning).

These tutorials are great introduction tells you the basics about leds and power and connecting them.

One more sugestion is to have attention in choise of the power source. I bought an PC PSU, not too expensive. But the PSU didn’t have any filters and the noise that she generate did affect the control off the strip.

Just to be clear. It is REALLY simple to setup. You just have to be aware of the power draw. Stay within those limits and you’re good.

All sorted and working, thanks all!

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