STM32 I2C Issue

[Mujtaba]

Dear friends,

I am using STM32f407vgt6 and a DS3231 RTC module and I use I2C1 peripheral to read date from DS3231.

It is working fine but after 10 or 12 minutes the I2C bus is continously BUSY and I do not know what to do.

Is there any way to control the bus and and reset the BUSY flag? I used Delays but it didn't work.

MH_StatusTypeDef MH_DS3231_GetDateTime(mh_ds3231_time_t* time)
{
	uint8_t data[7];
	uint8_t start_addr = DS3231_SECONDS;
	
	/* Read multi bytes */
#if (useCMSIS_OS_MUTEX == 1)
	
	if(osMutexWait(rtc_mutex_id, MAX_MUTEX_RTC_TIMEOUT) == osOK)
	{
#endif	
	
	  if(HAL_I2C_Master_Transmit(&RTC_HANDLE,DS3231_I2C_READ_ADDR,&start_addr,1,MAX_RTC_TIMEOUT) == HAL_OK){
			if(HAL_I2C_Master_Receive(&RTC_HANDLE,DS3231_I2C_READ_ADDR,data,7,MAX_RTC_TIMEOUT) == HAL_OK){				
				/* Fill data */
				time->seconds = MH_Bcd2Dec(data[DS3231_SECONDS]);
				time->minutes = MH_Bcd2Dec(data[DS3231_MINUTES]);
				time->hours 	= MH_Bcd2Dec(data[DS3231_HOURS]);
				time->day 		= MH_Bcd2Dec(data[DS3231_DAY]);
				time->date 		= MH_Bcd2Dec(data[DS3231_DATE]);
				time->month 	= MH_Bcd2Dec(data[DS3231_MONTH]);
				time->year 		= MH_Bcd2Dec(data[DS3231_YEAR]);
			}
		}
		else
			osDelay(500);
  		  
#if (useCMSIS_OS_MUTEX == 1)
 
		osMutexRelease(rtc_mutex_id);
	}
 
  else
	{
		return MH_TIMEOUT;
	}
	
#endif	
	
		
	return MH_OK;	
}

and I use freeRTOS and mutex as you see above.

Any helps will be appreciated in advance,

Mujtaba

[TDK]

The I2C_CR1_SWRST bit can be used to perform a software reset. From the reference manual:

Bit 15 SWRST: Software reset

When set, the I2C is under reset state. Before resetting this bit, make sure the I2C lines are

released and the bus is free.

0: I2C Peripheral not under reset

1: I2C Peripheral under reset state

Note: This bit can be used to reinitialize the peripheral after an error or a locked state. As an

example, if the BUSY bit is set and remains locked due to a glitch on the bus, the

SWRST bit can be used to exit from this state.

[Tesla DeLorean]

You'd perhaps need to clock it out of that state, so the peripheral releases the signal(s)