I had to go google for a minute to figure out what a esp12 was. Doh, it's the same 8266, stripped down. Does it even have a status LED? For 3 bucks shipped to my house, anything more than an unpopulated pcb is a bonus!
https://www.ebay.com/itm/NodeMCU-Lua...4-80ad70937bf3
Oh wait, that's considered a dev board. It has a micro usb port, a reset button and other accessories!