Inverter circuit in SBUS cable between the receiver and flight controller. Inverted output signal wire must be connected to transistor collector.
It should be noted that Futaba compatible SBUS protocol use the inverted serial RX signal between receiver and flight controller. Inverter cable is required when flight controller doesn't have inverter in S.Bus input. Usually it is Naze compatible FC.
Transistor can be one of common small form-factor NPN transistors: 2N2222, BC337, BC547B etc. or their SMD equivalents as well.
