2026-07-22 16-01-19.bin (4.4 MB)
Description
I am experiencing persistent GPS Glitch errors during pre-arm, even with the vehicle completely stationary on the ground.
This issue was already present before replacing both HERE4 modules, which is why they were replaced in the first place. After replacement, the behavior remains exactly the same.
Setup
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Flight Controller: Cube Orange+
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Firmware: ArduPilot 4.5.7
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GPS: 2x HERE4 (DroneCAN)
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Configuration:
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Dual GPS enabled
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DroneCAN connection
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Environment:
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Open sky, good GNSS conditions
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Another identical drone (same setup, same location) works perfectly
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Observed Behavior
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GPS Glitch occurs during pre-arm (no movement, no vibration)
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Happens consistently after boot
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EKF rejects GPS even though solution appears valid
GPS Data (GPS1)
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HAcc: ~0.8 m
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VAcc: ~1.4 m
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SAcc: ~0.15 m/s
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No major degradation in accuracy
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Occasional message delay spikes (~400 ms)
PM (Performance Monitor)
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No scheduler overruns (NLon = 0)
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No internal errors
CAN
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No bus errors
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No overflows
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No packet drops
However:
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Significant Clock Drift (~ -200 ms) observed
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Loop rate appears to drop during glitch events (from ~400 Hz to ~20 Hz in plots)
Observations
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GPS data quality is good
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No indication of GNSS reception issues
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No CAN errors
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CPU overload
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Problem occurs even when stationary
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Replacing both HERE4 modules did not solve the issue
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Another identical drone (same hardware/config/location) works normally
Tests already performed
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Replaced both HERE4 modules → no change
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Verified GNSS quality → good
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Compared with identical drone → no issue on other unit