Driving WS2812b with STM32 and PWM strange behavior
Additional power wires are set to supply external power to the LED strip.
1. not to overload the controller if it is low-power, and.
2. if several LED bands are connected in series - supply external power to subsequent bands. otherwise, due to the voltage drop in the thin wires of the strips, the latter in the circuit will not receive enough power and will either light up barely or not at all.