daniel-p-carvalho opened a new pull request, #20988: URL: https://github.com/apache/nuttx/pull/20988
## Summary The ADC calibration was started 10 us after enabling the ADC voltage regulator. The STM32G4 datasheet (DS12288, table "ADC characteristics") gives tADCVREG_STUP as 20 us at most. Wait 20 us on the G4 and keep the 10 us for the other chips that share this code. ## Impact - New feature added? NO - Existing feature changed? YES, the G4 ADC waits 20 us instead of 10 us before calibrating - Impact on user (will user need to adapt to change)? NO - Impact on build? NO - Impact on hardware? YES, STM32G4 only, one longer delay per ADC open - Impact on documentation? NO - Impact on security? NO - Impact on compatibility? NO ## Testing Host: Linux x86_64, arm-none-eabi-gcc 15.2.1. Target: custom STM32G474RE board, NuttX `master` plus this patch, ADC1 opened 200 times, each open recalibrating. Result: no failures. The calibration factor (`ADC_CALFACT`) read after each calibration was 0x40 (191 times) or 0x3F (9 times), against 0x40/0x41 with the old 10 us delay. I did not find a failing case with 10 us on this board, so this is an adjustment to the datasheet and not a bug fix. `checkpatch.sh -c -u -m -g` passes. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
