STM32WB BLE advertising stops after exiting standby mode.

[AbidSulaiman]

Hello,

I am currently on the (official) example application of BLE_p2pServer from STM32Cube_FW_WB_V1.0.0. I am trying to make it work with standby mode and I disabled the advertising timeout for this particular test.

BLE is still advertising when in standby mode (before waking up). But it stops after waking up.

EDIT: BLE actually stops advertising as soon as it enter standby mode.

if(   (__HAL_PWR_GET_FLAG(PWR_FLAG_SB) != RESET)
      && (__HAL_PWR_GET_FLAG(PWR_FLAG_C2SB) != RESET)
     )
   {
     /* Clear Standby flag */
     __HAL_PWR_CLEAR_FLAG(PWR_FLAG_SB);
     __HAL_PWR_CLEAR_FLAG(PWR_FLAG_C2SB);
   }
  else {
    MX_RTC_Init();
    APPE_Init();
  }

From the code, i didnt reinitialize RTC and BLE after exiting standby mode as i thought the microcontroller starts from RESET after exiting standby mode.

The microcontroller will enter standby mode when the SCH_Idle() function is called.

void SCH_Idle( void )
{
#if ( CFG_LPM_SUPPORTED == 1)
    LL_C2_PWR_SetPowerMode(LL_PWR_MODE_STANDBY);
    HAL_PWREx_EnableSRAMRetention();
    HAL_PWR_EnterSTANDBYMode();
    Error_Handler();
#endif
  return;
}

Where do you think I went wrong? Thanks for the reply and help.

P/s: For now, I just use the NRST pin to wake up from standby. It is because when I use the RTC wakeup, I got some weird event where the microcontroller didnt enter standby mode again after exiting standby mode for the first time and went to the while loop in Error_Handler(). I didnt look deeper for this event yet. will post a question when I think I know where the error come from.

[azzurri]

I've fixed the problem by setting the MAC RX OFF before going to Standby. Anyway, thanks again.

[chinmaydixit]

Where should I write these lines. Should I write these lines in void UTIL_SEQ_Idle( void ) or somewhere else?

Thanks in advance.

[Christophe Arnal]

Hello,

There is nothing to add to provided example to enter stop mode and get the best low power consumption. Only some configuration are required to be changes in app_conf.h

Regards.

[chinmaydixit]

Hello, @Christophe Arnal​ ,

Thanks for the reply. I used BLE_HeartRate which is on github for stm32wb55. But I am seeing 6 mA current with having your settings as you have suggested. I am measuring the current on ST's Power measurement Board. Please guide me.

Thanks in Advance.