A rangefinder or proximity sensor was found

InformationRangefinder, optical flow, camera, OSD and other devices

What ArduPilot says:

RPLidar: (…)
RangeFinder[N]: added DroneCAN node N addr N
LightWare … detected
Prx[N]: added DroneCAN node N addr N
LightWare … detected (I2C)
TFS20L: found fw version N.N.N

Also explained here: 2 more

RPLidar … hw=N fw=N.N
TFMiniPlus: found fw version N.N.N

Good news at start-up: a distance sensor answered and its driver is running. The DroneCAN lines give the sensor's slot counted from 0 (“RangeFinder[0]” is RNGFND1, “Prx[0]” is PRX1), its CAN node number and the address it reports; the others give the model and its firmware version. If you expected such a line and it is missing, the sensor was not there when the board booted.

The code that sends it

RPLidar: (…)

libraries/AP_Proximity/AP_Proximity_RPLidarA2.cpp AP_Proximity_RPLidarA2::get_readings() · Open in ArduPilot Copter-4.7.1

RangeFinder[N]: added DroneCAN node N addr N

libraries/AP_RangeFinder/AP_RangeFinder_DroneCAN.cpp AP_RangeFinder_DroneCAN::get_dronecan_backend() · Open in ArduPilot Copter-4.7.1

LightWare … detected

libraries/AP_RangeFinder/AP_RangeFinder_LightWare_GRF.cpp AP_RangeFinder_LightWareGRF::check_config() · Open in ArduPilot Copter-4.7.1

Prx[N]: added DroneCAN node N addr N

libraries/AP_Proximity/AP_Proximity_DroneCAN.cpp AP_Proximity_DroneCAN::get_dronecan_backend() · Open in ArduPilot Copter-4.7.1

And 4 more messages, sent from the same places.