(23-Aug-2020, 01:07 PM)SnowLeopardFPV Wrote: You need to put the orange wire on the TBS(TX1) pad and not the Invertor(TX1) pad.

Be aware that we've seen some issues with the UART1 pads on the Mamba F405 boards not working as expected, so if it doesn't work then you may end up needing to use a different UART. But lets try UART1 first to avoid wasting that UART which won't then be useful for anything else.

Snow,

Got my R9MM OTA. I would like to ask whether I connect the Inventor TX1 pad to the Inverted S-Port of the receiver to make F-Port work. Or do I use the TBS TX1 pad? 

Thanks.

(16-Sep-2020, 04:09 AM)Zeuq Wrote: Got my R9MM OTA. I would like to ask whether I connect the Inventor TX1 pad to the Inverted S-Port of the receiver to make F-Port work. Or do I use the TBS TX1 pad? 

You need to connect the "Inverted S.Port" pad on the R9MM OTA to the TBS(TX1) pad on the Mamba F405 MK3 Mini FC.

(16-Sep-2020, 10:07 AM)SnowLeopardFPV Wrote: You need to connect the "Inverted S.Port" pad on the R9MM OTA to the TBS(TX1) pad on the Mamba F405 MK3 Mini FC.

Tried TBs (TX1) pad Setup FPort in BF and in the receiver option no stick inputs. Tried all combination of Serialrx_Inverted/halfuples. Still nothing. Connected to TX3 and set-up Serial on UART3. It worked. Inverted=No Halfduplex=YES. Telemetry working.

The Mamba F4 FC's seem to have an inherent design flaw on the TX connection for UART1. I always get people to try it in the hope that maybe only a few FC's are affected or that maybe Diatone fixed the issue, but it still appears to be problematic even on the MK3 boards which is a shame because it effectively means that one of the UARTs on that board is wasted.

At least you got it working on a different UART.