Difficulties with BLE_ADV_EVT_SLOW occurring.

[Robert]

I am not seeing a transition to BLE_ADV_EVT_SLOW.  The transition I see goes from FAST to idle, without a transition to slow, from the configuration I don't expect to be in IDLE.

init.config.ble_adv_fast_enabled = true;
init.config.ble_adv_fast_interval = app_data.advfast_interval;
init.config.ble_adv_fast_timeout = app_data.advfast_timeout;

init.config.ble_adv_slow_enabled = true;
init.config.ble_adv_slow_interval = app_data.advslow_interval;
init.config.ble_adv_slow_timeout = 0;

err_code = ble_advertising_init(&m_advertising, &init);
APP_ERROR_CHECK(err_code);

Have placed some debug logs to see the transitions:

static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
  switch (ble_adv_evt)
  { 
    case BLE_ADV_EVT_FAST:
    NRF_LOG_INFO( "BLE_ADV_EVT_FAST:" );
    LEDS( if( m_led_on ) bsp_board_led_on(ADVERTISING_LED) );
    break;

    case BLE_ADV_EVT_SLOW:
      NRF_LOG_INFO( "BLE_ADV_EVT_SLOW:" );
      break;

    case BLE_ADV_EVT_IDLE:
      NRF_LOG_INFO( "BLE_ADV_EVT_IDLE:" );
      advertising_start( false );
      break;

    default:
    break;
  }

}

The log output I receive show:

<info> app: BLE_ADV_EVT_FAST:
<info> app: BLE_ADV_EVT_IDLE:
<info> app: BLE_ADV_EVT_FAST:
<info> app: BLE_ADV_EVT_IDLE:
<info> app: BLE_ADV_EVT_FAST:
<info> app: BLE_ADV_EVT_IDLE:
<info> app: BLE_ADV_EVT_FAST:
<info> app: BLE_ADV_EVT_IDLE:
<info> app: BLE_ADV_EVT_FAST:
<info> app: BLE_ADV_EVT_IDLE:
<info> app: BLE_ADV_EVT_FAST:

This is with a S140 release of the SDK.

[Martin Lesund]

Hi Robert,

Some questions:

• You have tagged this case with nRF52832, but you use s140 ? (that does not compatible -> s140 is for nRF52840 and s132 is for nRF52832)
• What SDK version are you using and what example are you basing your application on?

what is inside your advertising_start() function?

What are you trying to achieve? 

 

[Robert]

Sorry, it is S132 what I had downloaded was a 14.0 SDK.  What I have was originally based on the NUS example for a peripheral.  

static void advertising_init(void)
{
  uint32_t err_code;
  ble_advertising_init_t init;
  memset( &init, 0, sizeof(init) );

  init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
  init.advdata.include_appearance = false;
  init.advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

  init.srdata.uuids_complete.uuid_cnt = NUM_ELEMENTS( m_adv_uuids );
  init.srdata.uuids_complete.p_uuids = m_adv_uuids;
  init.evt_handler = on_adv_evt;

  init.config.ble_adv_fast_enabled = true;
  Init.config.ble_adv_fast_interval = app_data.advfast_interval;
  init.config.ble_adv_fast_timeout = app_data.advfast_timeout;

  init.config.ble_adv_slow_enabled = true;
  init.config.ble_adv_slow_interval = app_data.advslow_interval;
  init.config.ble_adv_slow_timeout = 0;

  err_code = ble_advertising_init(&m_advertising, &init);
  APP_ERROR_CHECK(err_code);

  ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}

The desired outcome was to be allow the fast period to be able to run for a limited amount of time followed by the slow which would advertise at a lower rate until connected.  When advertising in FAST, a higher tx power is used to allow for a longer range for reconnection, when transitioning to SLOW a lower tx power will be set forcing the central to be closer to establish an initial connection.  Upon connection the tx power is increased allowing the range to extend again.

[Robert]

By changing advdata.flags to BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE, I now see the device transitioning from FAST to SLOW, however with a slow timeout of 0 I still see a transition to IDLE which is unexpected.  I believe a timeout of 0 should not timeout.

[Martin Lesund]

Correct, having the timeout set to zero will not make it timeout. The reason why you transition to IDLE must come from something else. 
I just tested this with the standard "ble_app_uart" example and added the following to the advertising_init():

and transitioned to BLE_ADV_EVT_SLOW after my desired "APP_ADV_TIMEOUT_IN_SECONDS". (and it did not go into IDLE)

please take an extra look in the Advertising Module documentation

[Robert]

This is the same, advertising slow interval is 3200, should be 2s.  I don't do anything with the events in on_adv_evt, the device appears to still advertise in slow until connected.  I just don't understand why I see a transition through IDLE.

static void advertising_init(void)
{
  uint32_t err_code;
  ble_advertising_init_t init;
  memset( &init, 0, sizeof(init) );

  init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
  init.advdata.include_appearance = false;
  init.advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;

  init.srdata.uuids_complete.uuid_cnt = NUM_ELEMENTS( m_adv_uuids );
  init.srdata.uuids_complete.p_uuids = m_adv_uuids;
  init.evt_handler = on_adv_evt;

#ifdef _NOTIFY_
  ble_advdata_manuf_data_t manuf_data;
  manuf_data.company_identifier = 0xFFFF; // ID not obtained yet
  manuf_data.data.p_data = (uint8_t *)&m_notification_info;
  manuf_data.data.size = sizeof( m_notification_info );
  Init.advdata.p_manuf_specific_data = &manuf_data;
#endif

  init.config.ble_adv_fast_enabled = true;
  init.config.ble_adv_fast_interval = app_data.advfast_interval;
  init.config.ble_adv_fast_timeout = app_data.advfast_timeout;

  init.config.ble_adv_slow_enabled = true;
  init.config.ble_adv_slow_interval = app_data.advslow_interval;
  init.config.ble_adv_slow_timeout = 0;

  err_code = ble_advertising_init(&m_advertising, &init);
  APP_ERROR_CHECK(err_code);

  ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}

[Martin Lesund]

Hello Robert,

Have you tested out what I did in the last post I made?

Because I did not get the issue you describe. 

[Robert]

I have...the actual code I was using at the time is posted above, it already had a change similar to yours.  I still see a transition to the IDLE event however advertising does not stop.  Changing to general discovery corrected the issue where advertising was stopping.