I got a question about externally powering my NodeMCU V3. It has an onboard voltage regulator (3v3) which breaks out to 3 header pins. Now I want to power 3v3 from an external board. Can I supply 3v3 to all of those pins at the same time? (Basically connected in parallel). Anyone has done this before or has this experience with NodeMCU V3?
I have supplied a link below: https://www.theengineeringprojects.com/2018/10/introduction-to-nodemcu-v3.html
Thanks a lot!
Yes, you may connect all 3V pins together (red) and all GND pins together (black), like so:
In some cases, more wires will improve the circuit. E.g. when you build the Ben Eater 8-Bit CPU, you'll find that connecting power in a ring instead of a line will reduce voltage drop by about 50%.
When first reading your question, I got the impression that you wanted to solder the 3.3 V wires directly to the voltage regulator. Here's my original answer for that:
That's not a good idea: if you connect the same wire to all pins, your're creating a short, typically causing a malfunction if not worse. You may destroy your equipment (external board as well as the NodeMCU v3). Do NOT connect 3.3V to all pins of the voltage regulator.
A voltage regulator has 3 pins:
The only pin to connect the voltage to is the "voltage in" pin (VIN). And typically, a development board has a pin for that:
However, you'll find that the input voltage must be between 4.75V and 10V, so supplying 3.3V from an external board is not sufficient.
If you have regulated (stable) 3.3V already, you can connect that to a pin labelled 3V:
Also, you need to connect the grounds (GND) of both circuits together (GND of external board to GND of NodeMCU), otherwise the current will not find its way back.
