Hi Nils,
auch wenn du meinst das ist nirgends wo dokumentiert:
Handbuch zum Extension Board Seite 2 und 3:
☆RSSI: If connected to a RSSI Output you can read RSSI voltage values on your OSD. Please remember to enable RSSI option in your OSD menu.
The Value shown will be like "330", which means your RSSI voltage is 3,3V.
How to work with the RSSI values?
Since the voltages of the RSSI signals differ between different makes of RC-receivers, it is not possible to simply show a percentage. In some receivers the RSSI voltage changes in a linear fashion, while in others it changes logarithmically. So to show RSSI values as a percentage it would be necessary to add a complex tuning capability. So far the hardware of the TeleFlyOSD doesn´t support that.
To use the RSSI function in your FPV flights we recommend that you experimentally check the corresponding RSSI voltages once glitches occur. Be careful! As a starting point it might be good to check the RSSI value with your RC-transmitter switched on and off, that gives you the range of your RSSI voltages. Another method would be the "range check". For 35/40/72Mhz (and others) simply pull out your transmitter antenna one segment and walk away with your transmitter. Have a friend signal you once glitches occur. Write down the corresponding RSSI value. That should be the point you would want to avoid in later flights.