Im using a 5v 1A power supply and connected to VIN pin on the NodeMCU. I also use 18650 battery to keep NodeMCU running in case the power supply shuts off due to power interruption.

I'm planning to use the 5V from power supply, convert it to 3.3V with voltage divider and connect it to the gpio to detect power interruption.

Is it possible? Can the NodeMCU handle the current from the power supply?


Yes, you can. You need to convert the 5V down to 3.3V with a voltage divider. You also need to consider how you are going to operate the ESP8266 when there is no power.

  • Can the gpio handle the 1A current? – Tobot Jan 6 '19 at 12:30
  • That question makes no sense. – Majenko Jan 6 '19 at 12:31
  • What about the current of the power supply? I'm worried that it may damage the NodeMCU – Tobot Jan 6 '19 at 12:38
  • What about the current of the power supply? Why do you think that factors into anything? – Majenko Jan 6 '19 at 12:38
  • 1
    @Tobot What Majenko is trying to say, in the most condescending way that can be conjured at this time, is that you need to do some reading on the fundamentals of electricity. The GPIO pin determines what current it draws from the power supply, not the other way round. A supply could be rated for 1A or 1000A: if a connected device only needs 1uA, it will only draw 1uA. – CharlieHanson Jan 6 '19 at 13:12

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