user66308: Can we use the vin pin of the lolin v3 nodeMCU as a 5V supply. If yes, i checked mine with a multimeter. At max, it gives a voltage of 2V. Is my pin blown out? Also, can use the VU pin as a 5V supply? Will using it cause any problems to my laptop's USB port? Can somebody help me out?
I need 5V to drive a relay using the v3

user62523: On the NodeMCU “v3” (and only on the v3) there’s a pin called VU (Vusb) that is connected to the +5V on the USB bus of the NodeMCU socket. This pin can be used to feed external components when it’s connected to USB, within the limits of the USB power supply it’s connected to.
The Vin pin (which is available on all NodeMCUs (and not just the v3) is a +5V power input which can be used to power the NodeMCU if it is not connected to USB. It can not be used as an output and it needs a stabilized supply.

66308: <p>Can we use the vin pin of the lolin v3 nodeMCU as a 5V supply. If yes, i checked mine with a multimeter. At max, it gives a voltage of 2V. Is my pin blown out? Also, can use the VU pin as a 5V supply? Will using it cause any problems to my laptop's USB port? Can somebody help me out?</p>

<p>I need 5V to drive a relay using the v3</p>
 62523: <p>On the NodeMCU “v3” (and only on the v3) there’s a pin called VU (Vusb) that is connected to the +5V on the USB bus of the NodeMCU socket. This pin can be used to feed external components when it’s connected to USB, within the limits of the USB power supply it’s connected to.</p>

<p>The Vin pin (which is available on all NodeMCUs (and not just the v3) is a +5V power <em>input</em> which can be used to power the NodeMCU if it is not connected to USB. It can not be used as an output and it needs a stabilized supply.</p>
