I want to power my nodemcu module with 3.3 V.

Does powering it with 3.3 V also power USB-UART module?

If so I do not want this as it eats the battery.

enter image description here

  • What is the version of you NodeMCU? Jul 24, 2018 at 11:21
  • @BenceKaulics 2nd generation / v1.0 / V2 Jul 24, 2018 at 11:24
  • if you want low power, you really need to get away from modules and especially devkits.
    – dandavis
    Jul 26, 2018 at 18:32

1 Answer 1


Yes, the schematic of the v1.0 NodeMCU shows that the 3.3 V bus is directly connected to the CP2102 chip.

enter image description here

You have two possibilities:

  1. Cut the 3.3 V trace on the PCB before the CP2102 chip. Not recommended as you will disable your programming interface and would be hard to restore it.
  2. The reset pin (RST) pin of the CP2102 is floating, you can try to pull it down to GND and keep the chip in reset, to see if that makes it any better.
  • But in deepsleep mode when the current is measured with a multimeter it is 0.000 Jul 24, 2018 at 12:04
  • Are you sure that you are measuring it correctly? 0.000 seems strange also it means nothing without units. Jul 24, 2018 at 12:32
  • Sorry it is showing 0.00 Jul 24, 2018 at 13:18
  • And is it kA, A, or uA it matters a lot? 0.00 without SI unit is just a number and nothing else. Jul 24, 2018 at 13:21
  • 0.00 amperes using multimeter Jul 24, 2018 at 13:22

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