LED Button Service Server GATT code Question:)

RE: LED Button Service Server GATT code Question:)

Soojin — Tue, 28 Jul 2020 22:33:46 GMT

Thanks! It really helped alot:)
Have a nice day

RE: LED Button Service Server GATT code Question:)

awneil — Tue, 28 Jul 2020 17:29:57 GMT

For example, we find the definition of NRF_BLE_GATT_DEF() in nrf_ble_gatt.h:

/**@brief   Macro for defining a nrf_ble_gatt instance.
 *
 * @param   _name   Name of the instance.
 * @hideinitializer
 */
#define NRF_BLE_GATT_DEF(_name)                        \
static nrf_ble_gatt_t _name;                           \
NRF_SDH_BLE_OBSERVER(_name ## _obs,                    \
                     NRF_BLE_GATT_BLE_OBSERVER_PRIO,   \
                     nrf_ble_gatt_on_ble_evt, &_name)

Note that the created variable is static - Nordic use the m_ prefix to identify file-scope statics

RE: LED Button Service Server GATT code Question:)

awneil — Tue, 28 Jul 2020 17:22:49 GMT

They are #defined macros.

Use your IDE's code browsing facilities to find the definitions of those macros.

What they do is to create the variable given within the parentheses:

BLE_LBS_DEF(m_lbs) creates a variable called 'm_lbs' - this is the data structure used to control the LED Button Service
NRF_BLE_GATT_DEF(m_gatt) creates a variable called 'm_gatt' - this is the data structure used to control the GATT module

You will find that Nordic is this approach a lot throughout the SDK.

[quote userid="92004" url="~/f/nordic-q-a/64276/led-button-service-server-gatt-code-question"]what does "instance" exactly mean here[/quote]

https://en.wiktionary.org/wiki/instantiation