Process to set up Telemetry and RSSI, for OSD and Transmitter.
SPM4649T Receiver - Telemetry
Solder signal wire to an open Tx not Rx.
Betaflight - Ports Tab
Turn on the UART where signal wire is soldered to.
Betaflight - Config Tab
Set to Spektrum serial receiver.
BF 10.2 and older - Set to Spektrum BIDIR
BF 10.3.1 (Current) - Set to Spektrum2048/SRXL
RSSI ADC - Off
Telemetry - On
Save and reboot.
Receiver Tab:
Set to Spektrum/Graupner/JR.
RSSI Channel - Set to unused available AUX channel.
Save.
OSD:
Turn on RSSI Value.
Place in desired location.
Save.
Transmitter:
Telemetry - Auto Config if available.
Empty slot - Set to Text Gen turn on display and save.
Verify AUX channel used for RSSI channel is open.
I hope this helps for those like me that are trying to use telemetry and have RSSI warnings when flying. Any questions feel free to reach out and I will help with what I can.
Thank You,