I continue struggling with my first FPV setup.
Already went through multiple issues with firmware, radio, motors and now I'm on the last (hope) stage — setting up OSD.


Shortly about my setup:
FC: Darwinfpv 15A 1-3S F411 Ultralight/Whoop AIO
Camera: Eachine TX06 NTSC with integrated VTX
Goggles: Eachine EV800

Camera has 6 wires: power, GND, VIn, VOut, Smart audio, GND 2(why?)
I soldered power and GND to the FC.
When VIn and VOut are shortened I see the picture in the goggles. I found the right band, it seems works fine.

Now it's time to connect it to the FC to get OSD.
My FC is not documented well, but I see 2 pads called CAM and VTX. I guess it should be connected like this: VOut-CAM, VIn-VTX.
I soldered it like that and I get black screen and no OSD in my goggles. I tried switch wires just in case, the same result.

In BetaFlight OSD is on, some OSD items are placed, NTSC is selected.


Some things that concern me:
1. In BF's Video Transmitter tab I see nothing but the following warning: "ATTENTION: You VTX is not configured or supported. So you can't modify the VTX values from here. This will only be possible if the flight controller is attached to the VTX using some protocol like Tramp or SmartAudio and is correctly configured in the ports tab if needed."
2. Description to the camera says the following without any further explanation: "OSD configuration using FC UART". What does it mean? I don't clearly understand how UART comes to the stage here?

Am I missing something? Any additional config required? Anything to check?
Looking for help.

smartaudio let you settup the vtx over the the fc, by osd and transmitter. 
ot requires to setup smartaudio in the ports tab in betafliight configurator, enable smartaudio if not allready enabled.
you need to find the vtxtable for your particular vtx and after apply you should be able to use it and set the channel and power in bfc.
https://oscarliang.com/smartaudio-tramp-...vtxtables/