To make the DIY process easier, I designed a small PCB.
Design Files:
You can also order them on OSHPark:
You’ll have to solder a Pro Micro board on one side and a Wemos d1 mini
or NodeMCU board (depending on the PCB) on the other side.
That’s it.
You don’t even have to solder all pins,
just the ones mentioned in Connections, excluding the LED.