PX4FLOW can not work outside

[gyzii]

Hello！I am working on PX4FLOW recently.Unfortunately, I have encountered some problems that I can't solve. I would be grateful if someone can help me solve these problems. Thank you!

Basic situation: Pixhawk(using ardupilot firmware)+PX4FLOW+Mission Planner

Problem 1:
I followed the tutorial on the website to install and debug PX4FLOW. （Here is the website:
http://ardupilot.org/copter/docs/common-px4flow-overview.html?highlight=px4flow#px4flow-optical-flow-camera-board）
However, the ground station shows that the parameters related to the optical flow, such as opt_m_x, opt_x, are always 0.

Problem 2:
When I was indoors, I armed the pixhawk to get the flight log.The log shows that the parameters related to the optical flow, such as flow_x, flow_y, are correct (at least I think). I also used QGroundControl for real-time data analysis. This shows that the optical flow sensor is working properly.

But when the copter is outdoors, the optical flow sensor does not function or record data. Whether the copter is on the asphalt road or on the grass, the Mission Planner reminds me that the optical flow is unhealthy.

These two problems have been bothering me for a long time. I hope that someone who is proficient in this area can help me solve the problem. thank you very much!

[mike239x]

Well, that is unusual, it is supposed to work better outdoors than indoors :)
You can try:

1. Moving slower.
2. Playing around with exposure (lowering it / trying autoexposure).
3. Trying some hacky stuff like changing NUM_BLOCKS in line 55 from 5 to 4.
4. Trying out klt branch of this repo (might work better, I don't know).