1. Connect the external receiver
(Support PPM/SBUS/IBUS/DSM2/DSMX) to Crazybee F3 flight controller like the bellowing picture.
2. Enable Serial RX for UART3
if you use SBUS/IBUS/DSM2/DSMX protocol serial-based receiver (PPM receiver don’t need to enable serial rx)
3. Choose the same protocol for your receiver
for example: Choose serial-based receiver and select SBUS for Frsky sbus receiver / Futaba Fasst, S-FHSS , Select IBUS for Flysky IBUS receiver , Select Specktrum1024 for DSM2 and Spektrum2048 for DSMX. PPM receiver please choose PPM RX input