I'm using R9 Slim+ OTA (type FCC) frysky receiver with Jumper T18.
  
I got problem as below here :

- I open bind (External module, equip with R9M module), press and hold the bind button on my

  receiver, plug the usb connection to my Flight Controller, release the press button. Receiver will flash

  with green LED.

  After that, I reconnect back the usb cable. Green LED won't be able to blink anymore. Why?

- Currently I facing with this problem, I flash my R9M and R9 slim+ with latest FLEX firmware. When I

  plug my receiver  and connect usb to my Flight Controller. It just blink only one times to RED LED

  and never turn on again but just dimmed (both GREEN and RED LED, unplug and replug mutiple
  times).

  My Wiring is as below:

      (CON1):

      VCC (Receiver) : +5 volt (Flight Controller)

      SBUS OUT (Receiver) : RX1 (Flight Controller, already enable telemetry port under PORT section of betaflight)

      Smart Port (green color, Receiver) : TX2 (Flight Controller, already enable serial on UART 2 in betaflight)

      Ground(Receiver) : Ground (Flight Controller)
 
      What is the problem?

Thanks

You want to enable serial rx under UART 1 and S. Port telemetry under UART 2.

(03-Mar-2021, 03:41 AM)voodoo614 Wrote: You want to enable serial rx under UART 1 and S. Port telemetry under UART 2.

ok, FYI, I'm previously flash with FLEX firmware (Not FPORT). Is it ok?

The short answer is yes.

TQ, I'll tried it once get back to home.

Unfortunately, what I asked you to do only correct the BFC settings. It will not address that your receiver is not binding to the module. Try reflashing the R9M and the receiver again. Then rebind.

Yea, It is worked. I solved the problem by flashing the correct firmware, I'm using R9 slim plus OTA but accidentaly flash with regular R9 slim plus firmware. That is why it is never turn on RED LED once connected to battery. BTW, Thanks for your help.

Glad you got it figured out.