I2Cv2 driver

[Emara]

Hi everyone,

I’m running into some issues with the I2Cv2 driver on STM32F769 in a high-noise I²C environment and would like some guidance:

1- When the driver receives a NACK, it stops communication on the bus and does not recover until I fully reinitialize the driver (calling i2cStart). Is it expected that recovery from a NACK should be handled at the upper layer, or should the low-level driver attempt automatic recovery?

2-Under very noisy conditions, I’ve observed bursts of interrupts that can trigger sometimes memory corruption (HardFault). I found a related issue in ArduPilot’s repository where they limited the number of isrs:

https://github.com/ArduPilot/ardupilot/pull/12896

However, this looks like an old workaround from 2019, and I haven’t found any equivalent fix in the current ChibiOS versions.

Has anyone here experienced similar behavior with the I2Cv2 driver?

[Giovanni]

Hi,

The driver can reach an I2C_ERROR state, it is meant to be restarted for recovery. Verify if you get an error state or if it is something else.

Giovanni

[Emara]

Hi thanks for replying,

Yes, for the first point of NACK,the driver reports I2C_ACK_FAILURE, then the driver needs to be restarted by upper layer to recover.
regarding the second point it is hard to reproduce but under high noise environment i get different kinds of errors that's okay, but the problem is the bursts that can cause memory corruption sometimes

[Giovanni]

Hi,

It is hard to handle at driver level, you should put control codes or CRCs in your memory for integrity check after transfer. On write you should always read-back and compare.

Giovanni