ESP32 Forum

I am following the code of gatts service table from example code
https://github.com/espressif/esp-idf/bl ... eat_demo.c

In the example there is the function which create the attribute table, esp_ble_gatts_create_attr_tab(constesp_gatts_attr_db_t *gatts_attr_db, esp_gatt_if_tgatts_if, uint8_t max_nb_attr, uint8_t srvc_inst_id).

the last parameter is the service instance id. I want to know the significance of this variable. what does it do? there is no explanation on that anywhere.

You can have few services with the same UUID and for that you need instance id. When you create 2 services with the same UUID and the same instance id you will endup with this error:
https://github.com/espressif/esp-idf/issues/2005