PixRacer configuration

Hi all,
I’m just taking the freedom to start a pixracer thread for Copter here. Is it possible to configure RSSI? I tried with 3.4dev by setting RSSI_ANA_PIN to 103 and RSSI_PIN_HIGH to 3.5 like I did for pixhawks. But no RSSI is reported in MP’s HUD: "rssi: 0"
I’m using an FrSky X8R receiver. RSSI is working ok with above configuration on a 3DR pixhawk.