Happymodel Crazybee F4 Pro V2.1 2-3S Compatible Flight Controller for Sailfly-X FPV Racing Drone Frsky/Flysky/DSM2/DSMX Protocol RX Item NO.: F28528-F28529-F28530-F28531

 controller

(Frsky version) CRAZYBEE F4FR PRO V2.1 Firmware target: CrazybeeF4FR

(Flysky version) CRAZYBEE F4FS PRO V2.1 Firmware target: CrazybeeF4FS

(DSM2/DSMX version) CRAZYBEE F4DX PRO V2.1 Firmware target: CrazybeeF4DX

(No RX version) CRAZYBEE F4 PRO V2.1 Firmware target: CrazybeeF4DX

MCU:STM32F411CEU6 (100MHZ, 512K FLASH)
Sensor: MPU-6000(SPI connection)

Board size: 28.5 * 28.5MM
Power supply: 2-3S battery input (DC 7.4-13V)

Built-in 5A(each) Blheli_S 4in1 ESC Dshot600 ready

Frsky version Built-in SPI Frsky receiver with telemetry(D8/D16 switchable)

Flysky version Built-in SPI Flysky receiver with telemetry(AFHDS/AFHDS2A switchable)

DSM2/X Version built-in Serial-based DSM2/DSMX compatible satellite receiver

No RX version need to add external Receiver

Built-in Betaflight OSD(SPI Control)

Built-in Current meter Max 28A

Current meter scale set to 1175

Built-in 5V 1A BEC with LC filter

Built-in voltage detection

Onboard 4in1 ESC

MCU upgraded to EFM8BB21

Power supply: 2-3S LiPo/LiPo HV (7.4v/13v)
Current: 5A continuous peak 6A (5 seconds)
Support BLHeliSuite programmable
Factory firmware: S_H_50_REV16_7.Hex
Default protocol: DSHOT600

Frsky receiver Version

SPI BUS receiver

Frsky D8/D16 switchable

Compatible both Non EU and EU-LBT transmitter Channels: 8ch or 16ch

EU-LBT support(need to update betaflght v4.0 date 2019-04-11)

Failsafe support

No ground interference ( Transmitter and receiver 1 m from the ground): 300m

Flysky receiver Version

SPI BUS receiver

Protocol: AFHDS and AFHDS-2A Switchable

Channels: 8ch(AFHDS) or 14ch(AFHDS-2A)

No ground interference ( Transmitter and receiver 1 m from the ground): 300m

Failsafe support

DSM2/DSMX receiver version

Serial bus receiver

Protocol: DSM2/DSMX compatible

Channels:6-9 (Depend on your radio)

No ground interference ( Transmitter and receiver 1 m from the ground): 300m

PNP No RX version

No RX version support external serial-bus receiver like xm+, crossfire, S-FHSS etc.