STM32 HAL I2C read

The code

Embedded C for Cortex-M. It compiles. There are 4 real bugs in it: the kind that pass a bench test and fail in the field.

#define SENSOR_ADDR 0x48   /* from the datasheet */

int sensor_read(uint8_t reg, uint8_t *val)
{
    HAL_I2C_Master_Transmit(&hi2c1, SENSOR_ADDR, &reg, 1, HAL_MAX_DELAY);
    HAL_I2C_Master_Receive(&hi2c1, SENSOR_ADDR, val, 1, HAL_MAX_DELAY);
    return 0;
}

What an interviewer expects

• Point to each line you'd stop in a code review.
• Say what actually breaks: the failure mode, not just the rule it violates.
• Fix it, then defend the fix when asked the follow-up.

The bugs, reference fixes and the follow-up question are in the practice app, after you've tried it.

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