Omnibus AIO F4 V6 F.Port issue

[dan412]

Hello,

I recently got this FC to use with an R9M Slim+ receiver. I can’t get FPort to work on any of the UARTs. The receiver works on a different FC. I’d appreciate if someone can confirm if this FC supports F.Port and how I can set it up. I have followed instructions for other FCs to no available. Also tried different configurations with serial_rx - no change.

PS:
Connection:
Smartport wire --> TX3

This is diff:

set serialrx_provider = FPORT
set serialrx_inverted = ON
set motor_pwm_protocol = DSHOT600

Thanks

[dan412]

Update: I eventually got it working with softserial on UART1.

[AlienskysFPV]

@dan412 I’d recommend not using softserial for your RX. This is form the BF developers “Softserial is not suitable for high duty cycle and ‘chatty’ applications that occupy too much processor time like OSD and serial RX”

You don’t say what the other FC was - but I’m guessing it was F3 or F7 based?

[dan412]

@AlienskysFPV - Yes, I believe it was on an F7 board (and maybe an F4, I’ll check). However, does this Omnibus F4 support Frsky F.Port? I could not get it to work - perhaps it is firmware related? The FC documentation recommends OMNIBUSF4FW while Betaflight Wiki suggests OMNIBUSF4V6.

[AlienskysFPV]

The correct firmware is the OmnibusV6 one - it does support F.Port but you will need to use a hack on the RX to get an Inverted S.Port pad. F.Port is an in-inverted Protocol and S.Bus / S.Port are inverted.

F3 and F7 controllers have software configured inverters using the CLI - however F4 controllers have no inversion - except those that have an S.Bus or S.Port pad that have fixed hardware inverters…

I’m just building a quad with F.Port and this FC right now so check back tomorrow and I’ll have more info.

[AlienskysFPV]

@dan412 The good news is I have it working with the OmnibusF4 V6 and an R-XSR (v2) using the following CLI settings:

set serialrx_halfduplex = ON
set serialrx_inverted = OFF
save

The bad news is that to get this to work I had to use the uninverted S.Port on the R-XSR - you can find where to get the uninverted signal for your RX here Uninverted SBUS and Smart Port on Frsky Receivers - Oscar Liang

[dan412]

@AlienskysFPV, thanks for response. I will check that guide to see what options are available for the R9 Slim Plus receiver.