when using a 3.3v board. So I can run a few ws2811 lights. without a separate power supply. the wall wart can handle it but do I have to take it apart and solder some wire or is there an easier way?
Unless you know exactly what you are doing, I would strongly advise against opening up a wall wart.
Simpler and safer to just get a 5V wall wart and generate your 3v3 from that.
but I need the usb part.
- What board?
- How many is "a few"?
6-18, nodemcu 1.0. has not 5v pin.
18 in flicker mode, 6 in on mode at any one time.
Can you post a photo of the wiring of the wall wart you have? Is it a USB or barrel plug or ???
I bet it does, but it might be labelled Vn. You should be able to run it from an ordinary 5v phone charger just like everybody else does, and not have to fartarse around with anything.
So 24 LEDs. That could be 24*0.06A = 1.44A peak.
That's too much to pass through a NodeMCU when powered from USB, and could burn the (<0.5A) USB backflow protection diode. Maybe safer to directly power the LEDs with a 5volt/2A supply, and also power the NodeMCU from that supply (on the V-in/5volt pin).
Should also use a 3.3 to 5volt level converter between NodeMCU and first LED if you want reliable LED operation.
Leo..
There is a Vin pin, but it didn't work for me. I saw a YouTube video where a guy used a diode from 5v into the esp, then a diode going from ground to PSU ground and that worked. I'll post a pic and see if you think it's a good idea.
yes, I have used these logic converters. they work fine but are a hassle, just wondering if I could cheat a little!
I have powered ESPs from a 5V line using three 1N4001 diodes in series. You should get something in the neighborhood of 3.2V.
The diode in the ground is counter-productive. Just connect all grounds together.
The WS28xx strips run nominally at 5V logic. If the ESP is close to the strip, like inches, then it may work without a data driver. I've wired the ESP GPIO directly to the LED data-in on a few projects. Each WS28xx chip conditions the data for the next chip, so if the first LED works, then all that follow will, too.
Irrelevant, because OP is using a NodeMCU (post#5).
Leo..
there are mini boards (often used with radio controlled aircraft) that drop 5v to 3.3v.
i didn't check the whole diode thing but one simple way would be to use a "voltage divider". two resistors in series from +V to ground. the midpoint puts out a lower voltage depending on the ratio of the two resistance values.
And, just what processor does the NodeMCU use?
The ESP chip can draw anything from 20uA to 170mA depending on how it's used, what WiFi mode is in use, or not and the duty cycle of the WiFi. A voltage divider would be a very poor regulator across that range of current. Using 3 diodes to acumulate the 1.8V forward drop is not as sensitive to power consumption.
Which ones? 74HC14 / 74HCT14 ?
Simple indeed!
Too simple. Simply cannot work. 