Vin Pin as 5V output in NodeMCU ESP8266 12E

Jaya's picture

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Joined: Sep 04, 2018

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Vin Pin as 5V output in NodeMCU ESP8266 12E
July 25, 2019 - 6:27pm

hi,

i know that the NodeMCU pins are 3.3 logic and also the NodeMCU ESP8266 board provides 3.3 output voltage in its output vcc pins. i noticed that that when i checked the Vin pin of NodeMCU with Multimeter, it was giving 4.9V which is enough to drive a 5V sensors like HC-SR04 and 16x2 LCDs.

my question is can i use this voltge to drive the 5V sensors? because my project uses 5V sensor.   

Ferry's picture

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Joined: Sep 20, 2018

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Vin Pin as 5V output in NodeMCU ESP8266 12E
July 25, 2019 - 6:46pm

Yes you can use it but also note that, the Vin pin is directly connected to the Micro USBs Supply voltage so in simple words whatever your USB will give the power same power will be outputted to Vin pin. So here your micro USB pin is outputting 4.9V so the same voltage you can read with digital multimeter.

Also note that you may not control the voltage i.e. it will fluctuate between voltages so suppose( 4.6V to 4.9 or other range. Also I would recommend not to connect 500mA current to Vin pin as it can affect your computer also can cause shut down. There is no back-power protection on the board.

So be careful. Also if you Vin pin is used to power the ESP board if you wil use it for output then you  won’t be able to power through it. So you will only have one source to power it i.e. micro USB port.