Lightware SF40/c Lidar range finder debug

Hi everyone,

I was wondering if you guys can give me ideas how to debug an issue I am having with the SF40/c Lidar.

A new Lightware SF40/c with the most recent firmware 1.5.0 is connected to Serial4 on a Pixhawk 2.4.8, flashed with Ardurover v4.1.2. The sensor looks a little different from what the SF40/c ardupilot page is showing. It was delivered with 6 bare wires, requiring 5V, 12V, and serial RX/TX. We made sure to have stable supply voltages on the rover.

The sensor works fine as verified with Lightware’s tool. Tried both at 115200 and 921600. Tried Serial4 and Serial5.

However, Missionplanner keeps showing a sonarrange of 0m.

Is there maybe a way to see what’s going on inside ardupilot on the Serial4 port? Or some other way to look into the communication between ardupilot and the sensor?

I will be happy to share more about the hookup with this version of the sensor once for others to replicate we have it working.

Thank you!