Nodemcu becomes unavailable when powered from relay, but works with external power, but then connected relay is humming - Hardware - Home Assistant Community
nodemcu - esp2866 powered externally not working - Arduino Stack Exchange
single 5V power source for ESP8266 and relay rack - General Electronics - Arduino Forum
diymore NodeMcu Base Module 5.5x2.1mm DC Power Supply Board for NodeMcu V3 ESP8266 ESP-12E CH340G WIFI Module for Arduino IoT
Getting Started with ESP8266 NodeMcu v3 - KaliTut
The beginner guide and getting started with nodemcu