Yes that’s the rangefinder output, so I assume this means that it is not configured correctly or is not in a suitable environment (small ToF sensors are best for indoors). Unfortunately I’m not familiar with the sensor, so I can’t offer any advice on getting it to work.
You can test if it’s giving sensible data without having to look at logs by connecting your GCS and watching the sonar range while moving the vehicle/sensor around.
@iter what you say exactly matches my results with that sensor. i added a rngfnd osd panel to provide live monitoring and couldn‘t reproduce the promising indoor / workbench results under outdoor real-life flight conditions.
You are not the only one. First bench tests were very promising too. Outdoors at daylight the VL53L1X seems to get short sighted beyond usability for planes. Tested with external arduino, never flown and abandoned the project.