About the relationship between API and events

[takashina hiroki]

SDK: 15.3.0
Example: ble_app_multirole_lesc
DeviceA: EYSHJNZWZ (nRF52832)

I want to know the relationship between API and events.
Take "sd_ble_gattc_characteristics_discover" as an example.

I expect to call “sd_ble_gattc_characteristics_discover” and get “BLE_GATTC_EVT_CHAR_DISC_RSP”.
Is there a case where "BLE_GATTC_EVT_CHAR_DISC_RSP" does not occur at this time?
Or does "BLE_GATTC_EVT_CHAR_DISC_RSP" always occur?
As a case where there is a possibility that "BLE_GATTC_EVT_CHAR_DISC_RSP" does not occur, we consider cases where there is no characteristic.

I gave "sd_ble_gattc_characteristics_discover" as an example, but I want to know the same for other APIs and events.
For example, “sd_ble_gattc_primary_services_discover” and “BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP”.

[Kenneth]

Hi,

You may find the message sequence charts useful:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.0.1/s132_msc_overview.html?cp=4_5_2_1_1 

In your case:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.0.1/group___b_l_e___g_a_t_t_c___c_h_a_r___d_i_s_c___m_s_c.html 

Best regards,
Kenneth

[takashina hiroki]

In your case:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.0.1/group___b_l_e___g_a_t_t_c___c_h_a_r___d_i_s_c___m_s_c.html 

When there is no response “ATT Read By Type Response” or “ATT Error Response: Attribute Not Found”, it seems that “BLE_GATTC_EVT_CHAR_DISC_RSP” does not occur.
Is there such a case?

[takashina hiroki]

I want to know the same about other APIs and events.
The answer I expect is that an event always occurs even when normal or abnormal.