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I'm not a hardware guy and I currently confuse myself a bit with powering the Wemos D1 mini.
If there is the information somewhere out in the net (I havent seen it) let me know.

Otherwise, you guys may be able to help.

Everywhere it is written that the Wemos is a 3.3v chip, right?

If hooked to the USB, the module gets 5V.
If hooked to the Wemos DC Power Shield, only the 5V pin is connected to the Wemos (the 3.3v is not connected)

So, 5V trough USB or the 5V pin would be the way to power the module?

Then I dont understand the 3.3v chip thing and why not just use a 3.3v source to power the Wemos and all other to the Wemos connected modules/sensors?


If using other modules hooked up to the Wemos that are also powered by 3.3v. What is best to use?
- a separate 3.3v source
- the 3.3v pin from the Wemos?
Well, you will ask me there how much have I connected to the Wemos? Well, a lot and in the end, wouldn’t I just be on the save side if I use an external 3.3v source (instead from the Wemos) to power those modules and sensors?

The reason for my asking, my current project involves a source of 20V (to power a motor), as step-down to 12v (to power a fan), a step-down to 5v (for the Wemos) and a step-down to 3.3v (for the other modules). It just doesnt make it easier...

Is there a way to power the Wemos through the 3.3v pin?

Well I had to try this myself.
Yes you can power the Wemos D1 Mini by supplying 3.3v to the 3v3 pin.

Then I dont understand the 3.3v chip thing and why not just use a 3.3v source to power the Wemos and all other to the Wemos connected modules/sensors?

Well this one's easy. If it's got to have a usb port on it anyway, might as well use it; and that means stepping 5v down to 3.3. The pin is there if you want to power it from another source (make sure it's very clean DC I imagine).