Optical Flow - Problems

[LavaChemist]

I am trying to get optical flow working. I have a Matek 3901-L0X. The lidar is working, and I am seeing optical flow data in my logs, so I know it is working. However, Mission Planner seems to be having a strange issue when displaying the data. The vertical zero point of my logs seem to be different.

Also, I tried enabling loiter. When I’m on the ground it will not arm in loiter mode, it complains that it needs a position estimate. If I switch to loiter in the air, it will start drifting and then if I try to counter the movement it causes it to fight me even more.

Here is a log I just pulled. I just armed in stab mode and rotated in X and Y axes manually to check the optical flow logs. Can anyone help me figure out what I need to adjust or change?

Optical Flow Log

[Allister (Allister Schreiber)]

There’s a bit of a setup with that board. Have a look at this thread:

MSP protocol support

Not sure if this is the correct thread for this, but there’s a strange anomaly in the log file, that the zero points for the graphs are offset. I did already put in the recommended value for flowxscaler = -800 so maybe I should start by zeroing those, but I’ll share this just in case: [Album] optical flow tuning 0 point offset [optical flow tuning 0 point offs…

[LavaChemist]

Wow, thanks! I was WAY off on my scaler. Hopefully that fixes it.

[LavaChemist]

Thanks for your help with that. I used -800 for the X scaler and -750 for the Y scaler and I’m now getting a pretty decent loiter position. Rad. Many thanks.