Controller 3 not connecting

[AJE Drone]

I have built my first FPV drone (should have gone BNF)
Using the speedybee F405 V3 with the 03 air unit connected to the goggles and controller 3.
I can connect the goggles to the air unit but cannot connect the controller.
In Betaflight the receiver section only shows white bars where there should be coloured ones.

I have tried flashing the firmware but have been unable to complete the process.
I have changed back to the backup firmware, but still nothing.

I have tried putting set sbus_baud_fast = on, but it returns an error about the invalid name.

Please, does anyone have idea what I have done wrong and what I can do to put it right?

 

[Dan]

Is the protocol set to SBus on the receiver tab ? Is the UART you connected the o3 air unit to ported as serial RX on the ports tab? Have you executed the linking process with all three devices powered on together? Could the Rx & Tx leads, or the signal wire & second ground leads from the air unit possibly be reversed? Just the things I would check. Good luck

 

[AJE Drone]

It turns out the the receiver needs to be set to UART 2 and not UART that the 03 air unit is plugged into.