In this video I make a breakout board for the ESP-12 wifi module using a plywood jig, wires, solder, scrap PCB, header pins, and hot melt glue.

I hook up the right combination of pull up and pull down resistors, and demonstrate it turning an LED on and off in response to MQTT messages. I draw up a circuit diagram to show how things connect.

Along the way I discover that GPIO4 and GPIO5 are swapped on the silkscreen of the ESP-12 boards I bought.

The Lua code for controlling the LED using MQTT can be found here:

https://github.com/lucsmall/Fairylights

I used the Nodemcu Devkit v1.0 schematic diagram as my reference:

https://github.com/nodemcu/nodemcu-devkit-v1.0/blob/master/NODEMCU_DEVKIT_V1.0.PDF