Development board for ESP8266-ESP01 in use
Example to go with the Instructable (https://www.instructables.com/Develop..., showing the development board prototype driving a simple 4 low power switch example. Board is powered via the USB cable, 12V cable is seen unconnected. Serial cable is connected to the board, but the serial lines are not connected to the ESP01, since all three selector switches are toward the output header.