Hello,

Thanks for reading me.

I'm trying to build a flying drone with some old stuff.
I have a damaged MK2 FC, where OSD doesn't work, so i connected then camera output to the vtx bypassing the RC and everything is OK, but no OSD.

The only important missing info from my point of view is to have the battey voltage, to know when to land.

My rx is a Fli14+, and my RC is a Turnigy Evolution.
It seems the Fli14+ has RSSI and telemetry output to transmit battery voltage.
The RC has an alarm system to monitor external voltage.

First question : How can the RX even know the battery voltage, i'm wiring a 5V input, and a signal output to a FC tx pad. Where is the magic ?
Second question : How can the rx send multiple info on the same channel (14) : RSSI and rx battery ?

In betaflight, i disabled telemetry osd, and choose the AUX 10 (Channel 14) for RSSI channel. I use IBus. Every command is working fine.
But on my RC, i still can't use the "External receiver" feature.

Can i do what i want with this material ? What am i missing ?

Thank youfor your help

Does your camera have OSD ?
You may be able to use camera OSD .
Also if your radio has opentx and a speaker you can get audio warnings at any voltage you want.

Foxeer Toothless Nano shows its voltage
Some action cameras also have it in OSD - they are designed for airplane which often doesn't have FC.
Hawkeye Firefly or something similar.