ARK Flow module sometimes only giving sporadic values

Hi all,

I am evaluating the ARK Flow optical flow module (together with separate 100m range finder), but there are issues with the optical flow module switching between “healthy” and “unhealthy” (SYS_STATUS. onboard_control_sensors_health).

I have done the basic setup from the wiki (DroneCAN and separate 100m RangeFinder) and the OF.flowX OF.bodyX IMU[0].GyrX test looks pretty ok (apart from a bit of flutter while I’m lifting it):

But when it stands still on the floor, I only see sporadic values (it seems to bottom out at 1Hz) which causes ardupilot to see it as unhealthy

Even more concerning is that I also got a 1 second “glitch” during the Y axis test:

Has anyone seen this before or have any hints as to what could be wrong?

Log file is available here