RC input

Connectors for providing RC input from a RC receiver module.

RDDRONE-FMUK66 Rev. C has a single RC input connector. It has PPM/SBUS, RSSI and Spektrum inputs, and a RC output that together with the PPM/SBUS input forms a UART TX/RX pair.

RDDRONE-FMUK66 Rev. B and older revisions had two connectors for input from the radio controller. The FRSKY port supports PPM and SBUS inputs and has telemetry output for an FrSky radio controller. The other connector, labelled RSSI/PPM, supports PPM, SBUS and Spektrum radio protocols. This port also has an RSSI input. FrSky telemetry is impossible when the PPM/SBUS input on either connector is also used.

FPV Protocols Explained (CRSF, SBUS, DSHOT, ACCST, PPM, PWM and more) - Oscar LiangOscar Liang

What is RSSI Transmitter Receiver - RC Quadcopter - Oscar LiangOscar Liang

RDDRONE-FMUK66 Rev. C RC input connector pinout

Pin	Signal	Voltage
1	VCC	+5.0V
2	RC IN (PPM/SBUS)	+3.3V
3	RSSI IN	+3.3V
4	SPEKTRUM IN	+3.3V
5	RC OUT	+3.3V
6	GND	GND

RDDRONE-FMUK66 Rev. C schematic

RDDRONE-FMUK66 Rev. B FRSKY connector pinout

Rev. B (and older boards) are not supported anymore. This information is left for reference.

Pin	Signal	Voltage
1	VCC	+5.0V
2	RC OUT (TELEM)	+3.3V
3	RC IN (PPM/SBUS)	+3.3V
4	GND	GND

RDDRONE-FMUK66 Rev. B FRSKY RC IN/RSSI connector pinout

Pin	Signal	Voltage
1	VCC	+5.0V
2	RC IN (PPM/SBUS)	+3.3V
3	RSSI IN	+3.3V
4	SPEKTRUM IN	+3.3V
5	GND	GND

RDDRONE-FMUK66 Rev. B schematic