[Solved] Wemos D1 Mini via external 5V power supply

Hallo Community,

I seem to hit a bump with my current project and would be glad if you guys could help me out

I am using a Wemos D1 Mini clone (Link). In the final project, i would like to power the board with 5V from an external source. I tried to hook up a 5V power supply to the 5V Pin of the board (and to ground of course).

Accourding to this article (Link) I used a 10kOhm pullup resistor between GPIO 0 and the 3.3V Pin of the Board, same for GPIO 2. Between GPIO15 and Ground is a 10kOhm pulldown resistor.

First Question: will this work? meaning, does the internal voltage regulator supply the 3,3V before the bootup?

The only result I get is a little flash of the onboard LED and then nothing. If I press reset, again a little flash and nothing afterwards.

During my time google-ing this problem, I also read, that the before mentioned PullUp/Down resistors are internally wired as well and i would not need them. Tried it without them with no luck either.

I would really appreciate your suggestions and help! :) Patrick

ps. forgive my english, not my first language ;)

Just power the WeMos D1 mini with a 5volt cellphone charger, connected to the USB socket. Or with the cellphone charger through a powerbank if you want battery backup. (a Wemos D1 mini runs ~36hours on a 5Ah powerbank).

A WeMos D1 mini does not need anything connected to the pins to work. Actually, connecting things to the wrong pins could result in not booting. Leo..

Hi Leo,

the final project will include a 12V LED strip. My plan is to use the 12V power supply and a 5V voltage regulator to run the D1 Mini of it - so i would really like to use the 5V Pin on the D1 Mini.

Alternativly, could i use the 5volts from the regulator and connect it to the micro USB socket via a sacrificed cable?


Looking at the D1 Mini schematic and the 5V pin is connected to the 5V USB via a diode (polarity protection?) and a fuse so you should be able to power the board with 5V applied to the pin but will lose the safety of the fuse/diode. The schematic also shows the D1 Mini board has GPIO0 & GPIO2 pulled up to 5V via 12K resistors and GPIO15 pulled to GND via a 12k resistor.

Thanks Riva

i will try it again later today and let you guys know how it went


Turns out the 5V phone charger i was using to power the D1 Mini is broken. With nothing attached the voltmeter shows 5V, but as soon as i connect the D1 Mini the voltage drops below 2V.

I used the 12V power supply with a 5V voltage regulator and it works like a charm.

Thanks for your help!! Patrick