Stop2Mode wake up, i2c don't work

GFont.1 · ‎2020-08-04

Hi,

I am using stm32l431 and work with LPTIM in stop2mode.

When the mcu wake up after stop mode, i2c stop working, so I need to restart mcu.

It's strange because in some cases the i2c work in the next 3 wake up, but after this dont work anymore. Should I init i2c after all wake up stop2mode ? I am using Alarm to wake up.

void sleep() {

if (__HAL_PWR_GET_FLAG(PWR_FLAG_WUFI)) {

/* Clear Internal WU Flag (RTC) */

__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WUFI);

}

__HAL_RTC_ALARM_EXTI_CLEAR_FLAG();

__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);

EXTI->PR1 = 0x00000000;

HAL_NVIC_EnableIRQ(RTC_Alarm_IRQn);

HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);

}

void HAL_RTC_AlarmAEventCallback(RTC_HandleTypeDef *hrtc) {

SystemClock_Config();

__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);

HAL_UART_Transmit(&huart3, (uint8_t*)"alarme callback\n\n", 17 ,HAL_MAX_DELAY);

}

nebusokuu · ‎2020-08-04

Please do this code after wakeup and SystemClock_Config().

__HAL_I2C_DISABLE(&hi2c1);
__HAL_I2C_ENABLE(&hi2c1);
HAL_I2C_MspInit(&hi2c1);