Dead simple 3.3v controlled WS2812B using stm32f103 (bluepill) and a mosfet and one 4.7k resistor
WS2812B controlled by 3.3v stm32 bluepill
Seems to work just fine, although the 3.3v to 5.0v conversion isn't the cleanest.
Maybe a lower value pullup resistor makes the signal go high a bit faster. Now it has 4.7k pullup and no gate resistor.