fix(bmp388): correct timestamp_sample to integration midpoint#26920
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fix(bmp388): correct timestamp_sample to integration midpoint#26920
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The BMP388 pressure measurement is integrated over a configurable window (e.g. 37ms at 16x oversampling). The previous code used the read time as timestamp_sample, which is the end of the integration window. Correct to the midpoint by subtracting half the measurement time, with a guard against unsigned underflow.
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I will follow up on this PR with fixes for every baro and mag driver. Related to #26921 |
julianoes
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Mar 31, 2026
hamishwillee
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Apr 1, 2026
The BMP388 pressure measurement is integrated over a configurable window (e.g. 37ms at 16x oversampling). The previous code used the read time as timestamp_sample, which is the end of the integration window. Correct to the midpoint by subtracting half the measurement time, with a guard against unsigned underflow.
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Summary
The BMP388/BMP390 pressure measurement is integrated over a configurable window (e.g. 37ms at 16x oversampling). The current code uses the SPI read time as
timestamp_sample, which corresponds to the end of the integration window. This introduces a systematic timing bias equal to half the measurement time (~18.5ms at 16x oversampling).This PR corrects
timestamp_sampleto the integration midpoint by subtractingmeasurement_time / 2, with a guard against unsigned underflow.This improves time alignment for all downstream consumers (EKF baro fusion, logging, etc.).
Changes
src/drivers/barometer/bmp388/bmp388.cpp: Replacehrt_absolute_time()with midpoint-corrected timestampTest plan