Hi, I use an F4 Omnibus V5.1 with iNav, one question, is it possible to use BOTH Frsky Telemetry and GPS? I was able to do that with my old F4 Omnibus Pro V2 with softserial activated, but with this one, seems more difficult. I’ve found a configuration on another post but seems to use the same TX as your configuration.
There are not enough UART ports, so what you will need to do is to enable softserial (as used in this guide) then that gives you an extra 2x UART ports… but just dont run anything critical on them… so I suggest you use GPS on a dedicated UART. and then Frsky telelmetry on a softserial one. Also check the CPU load to make sure it is less than 50% when everything is running so you dont run into any problems in the air.
Thanks for the quick answer. Is it the Pin CH6 for softserial?
I’m using iNav, I’ve seen the target is OMNIBUSF4V3 for the F4 Omnibus V5.1 board. But unable to activate softserial (Enable CPU Based serial port) with this Target. I have a message like "Unrevcoverable failure of serial connection, disconnecting…failed to close serial port…"and it doesn’t reboot automatically. Is F4V5.1 not supported by iNav?
Ok assuming there is a problem with iNav (can you confirm?), I did the exercise with Betaflight, is ok, thanks for your accurates instructions. So now, for Softserial, as I want to connect GPS to TX1 (tell me if I am wrong) can I connect the Softserial to CH6 or CH4 or even CH2? Could you give me the right SLI command for that? Because I’m a dummy 
I’ve seen there a table with Pins and signal: [BF] Configurable software serial ports - RC Groups
Is this CH2 → B15 CH6->C09?
You could use a DJI GPS puck. It uses one UART for GPS and compass. I’m using one on a Robocat with an Omnibus F4 Pro, which isn’t much different than your board.
