HEREFLOW SENSOR NOT WORKING as we connect it to mission planner it is showing bad opt flow and opt x,,y,z values are still zero

![HEREFLOW MISSION PLANNER|474x420](upload://jxdhciQYgG7wsyYAw6fK4qYacvL.pngVALUES NOT CHANGING )

Please read the docs. You need to set up the parameters
https://docs.cubepilot.org/user-guides/flow-senor/here-flow#settings

HEREFLOW SENSOR PIXHAWK 2.4.8.zip (73.4 KB)
Hi Alvin ,
Here we had used Pixhawk 2.4.8 for hereflow sensor and mission planner
As we had changed each and every parameter as mentioned in doc.cubepilot and ardupilot.org docs…still we are not able to solve the issue…as we are getting value as zero for opt m x,y z values…and getting the mesage as ‘No range finder detected’.so please find the link as we had attached the error message, while doing the sensor setup…kindly respond and help to solve the issue.

What is the firmware version on your autopilot?
Does the Hereflow show up when you connect to SLCAN?
https://ardupilot.org/copter/docs/common-mp-slcan.html

we are using firmware version is 4.1.0 and have doubt that in CAN cable whether CAN_H of sensor port connected to CAN_H or CAN_L of pixhawk

whether UAVCAN GUI neede to be installed

You can use SLCAN in Mission Planner. UAVCAN GUI is not necessary, even so Mission Planner should install it for you.

Not sure what is the problem with cable. Plugging in the CAN cable as it should. You can’t plug it reversely.


…while clicking on SLCAN mode CAN 1…no attached UAVCAN nodes are showing and it is getting disconnected.

Hi Alvin,
As we had carried out these many steps and procedures for setting up the hereflow sensor …Please find the attached links and kindly please respond…as we had undergone all the parameters setting and we are not able to solve the issue…so please respond
HEREFLOW SENSOR ISSUE.zip (537.1 KB)

It may be hardware issue and you may send it back for inspection. Please contact your local reseller for RMA.

Hi…Alvin … Thank you for suggestion…As the sensor is working now…I want one more clarification as how much will be the accuracy for precision landing…As we put the copter in RTL how much accurate will be precision landing.

The flow sensor can be affected by environmental light and the control precision of UAV. It is not feasible to conclude the specific accuracy.

As we give EK2_GPS_TYPE to 0 (enabling both Optical flow sensor and GPS ) the Position hold, Alt hold is not working .whether how much EK2_FLOW_DELAY must be given to Here flow sensor.

Is the rangefinder on Hereflow working good? You can check this from the status tab in bottom left corner of Mission Planner.

Also, what is the altitude you were trying to maintain? The distance sensor came with Hereflow works best at under 2m and indoor.

Thank you for the reply.

  1. while taking off in outdoor it is showing ’ Bad Lidar Health’.
  2. As can we use only optical flow sensor for autonomous navigation.Is it possible…and also in RTL we are not getting precision landing
    3.For first flight test in documentation both EK2 and EK3 must be changed or either ek2 or ek3 must be changed

Can you check if the TERRAIN_ENABLE is set to 1?

It is possible to bypass rangefinder in Flowhold. However, we don’t recommend it you should be in poshold.

Flowhold does not require rangefinder and was added because other hardware manufacturer has their optical flow product without rangefinder.

However, we think lidar is critical for flow. It needs the exact distance to the ground to know how far it has travelled.

You use either EK2 or EK3, so you just change either one of them.
https://ardupilot.org/copter/docs/common-apm-navigation-extended-kalman-filter-overview.html