Do I need to use a MOSFET to drive 60 WS281Bs?
If STM32 has Vdd max = 3.6 and WS2812 is CMOS input rated for 3.5 to 5.3 with Vih max &gt;= 0.7 * V+ then you need a level shifter to extend past &lt; 30% &amp; &gt; 70%.
Due to mismatched impedance of interconnecting cable some ringing occurs so a series R &lt;= cable impedance improves damping of ringing to Input. Twisted pairs might be 240 Ohms and driver might be 50 +/- 30%(?) so 180 to 220 might be ideal and 330 ohms should also work for these low(ish) clock rates.