Verifying GPS Use for Heading

dbitetto · July 28, 2024, 8:26am

Hi everyone,

I recently purchased the Holybro H-RTK Unicore UM982 GPS module and enabled GPS-based heading by setting the EKF2_GPS_CTRL parameter to 15. I would like to know how I can verify that the system is actually using GPS data for heading calculations instead of the compass.
What steps or parameters should I check to ensure that the configuration is correct and that the GPS is being used for heading?

Thanks in advance for your help!

JulianOes · July 28, 2024, 9:47pm

You can go to Analyze Tools → MAVLink Console in QGroundControl, and then do:

listener estimator_status_flags

And look for: cs_gnss_yaw

If you record a log, then you can look at it in PlotJuggler (or whatever tool you like) and look for ESTIMATOR_STATUS_FLAGS.cs_gnss_yaw.

github.com

PX4/PX4-Autopilot/blob/d841bf124fc3201c6d14add3ae65ce84187081d3/msg/EstimatorStatusFlags.msg#L29


      
          bool cs_ev_pos                # 12 - true when local position data fusion from external vision is intended
          bool cs_ev_yaw                # 13 - true when yaw data from external vision measurements fusion is intended
          bool cs_ev_hgt                # 14 - true when height data from external vision measurements is being fused
          bool cs_fuse_beta             # 15 - true when synthetic sideslip measurements are being fused
          bool cs_mag_field_disturbed   # 16 - true when the mag field does not match the expected strength
          bool cs_fixed_wing            # 17 - true when the vehicle is operating as a fixed wing vehicle
          bool cs_mag_fault             # 18 - true when the magnetometer has been declared faulty and is no longer being used
          bool cs_fuse_aspd             # 19 - true when airspeed measurements are being fused
          bool cs_gnd_effect            # 20 - true when protection from ground effect induced static pressure rise is active
          bool cs_rng_stuck             # 21 - true when rng data wasn't ready for more than 10s and new rng values haven't changed enough
          bool cs_gnss_yaw              # 22 - true when yaw (not ground course) data fusion from a GPS receiver is intended
          bool cs_mag_aligned_in_flight # 23 - true when the in-flight mag field alignment has been completed
          bool cs_ev_vel                # 24 - true when local frame velocity data fusion from external vision measurements is intended
          bool cs_synthetic_mag_z       # 25 - true when we are using a synthesized measurement for the magnetometer Z component
          bool cs_vehicle_at_rest       # 26 - true when the vehicle is at rest
          bool cs_gnss_yaw_fault        # 27 - true when the GNSS heading has been declared faulty and is no longer being used
          bool cs_rng_fault             # 28 - true when the range finder has been declared faulty and is no longer being used
          bool cs_inertial_dead_reckoning # 29 - true if we are no longer fusing measurements that constrain horizontal velocity drift
          bool cs_wind_dead_reckoning     # 30 - true if we are navigationg reliant on wind relative measurements
          bool cs_rng_kin_consistent      # 31 - true when the range finder kinematic consistency check is passing
          bool cs_fake_pos                # 32 - true when fake position measurements are being fused

I agree it would be nice if there was an easier way.

dbitetto · August 1, 2024, 4:37pm

Hi Julian,

I’m attaching these images. I did the test you mentioned, but it didn’t work. I see the parameter is set to false.

Any idea about this?
Maybe i have to disable or change other parameters?

JulianOes · August 1, 2024, 9:56pm

And that’s tested outdoor with good GPS signal, and you have verified that GPS itself is working properly?

petergerten · January 22, 2025, 1:11pm

I have exactly the same problem. GPS works but cs_gps_yaw shows false. Using UM982 dual antenna setup with latest px4 stable (1.15.2). Did you solve it eventually?

JulianOes · January 24, 2025, 5:29am

This will be fixed with 1.15.3. I have recently added a few fixes to the release/1.15 branch. If you build yourself from the release/1.15 branch, you already have the fixes.

AngelAlbeniz · January 29, 2025, 10:05am

Hi,

I have been testing behavior with the new version and have posted my findings in this other post.

Topic		Replies	Views
UM982 isn't providing heading data PX4 Autopilot	37	2114	March 14, 2025
UM982 dual Antenna heading	14	1407	September 28, 2023
Firmware v1.15 stable _ GPS not detected _ CUBE orange _ Herelink PX4 Autopilot	16	386	November 6, 2024
Invalid local and global position estimates when sending SensorGps uORB messages via uXRCE-DDS ROS 1 / ROS 2	10	2118	April 27, 2024
Lost global position in survey grid turns PX4 Autopilot	6	90	November 4, 2024

Verifying GPS Use for Heading

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