GATT module

Module for negotiating and keeping track of the maximum ATT_MTU size. More...

Modules
	GATT module configuration

Data Structures
struct	nrf_ble_gatt_evt_t
	GATT module event. More...
struct	nrf_ble_gatt_link_t
	GATT information for each link. More...
struct	nrf_ble_gatt_s
	GATT structure that contains status information for the GATT module. More...

Macros
#define	NRF_BLE_GATT_MAX_MTU_SIZE   GATT_MTU_SIZE_DEFAULT
	Default maximum ATT_MTU size. More...
#define	NRF_BLE_CENTRAL_LINK_COUNT   1
	Default maximum number of peripheral links. More...
#define	NRF_BLE_PERIPHERAL_LINK_COUNT   1
	Default maximum number of central links. More...
#define	NRF_BLE_GATT_LINK_COUNT   (NRF_BLE_PERIPHERAL_LINK_COUNT + NRF_BLE_CENTRAL_LINK_COUNT)
	The maximum number of peripheral and central links combined.

Typedefs
typedef struct nrf_ble_gatt_s	nrf_ble_gatt_t
typedef void(*	nrf_ble_gatt_evt_handler_t )(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t *p_evt)
	GATT module event handler type. More...

Functions
ret_code_t	nrf_ble_gatt_init (nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_handler_t evt_handler)
	Function for initializing the GATT module. More...
ret_code_t	nrf_ble_gatt_att_mtu_periph_set (nrf_ble_gatt_t *p_gatt, uint16_t desired_mtu)
	Function for setting the ATT_MTU size for the next link that is established as peripheral. More...
ret_code_t	nrf_ble_gatt_att_mtu_central_set (nrf_ble_gatt_t *p_gatt, uint16_t desired_mtu)
	Function for setting the ATT_MTU size for the next link that is established as central. More...
void	nrf_ble_gatt_on_ble_evt (nrf_ble_gatt_t *p_gatt, ble_evt_t *p_ble_evt)
	Function for handling BLE stack events. More...
uint16_t	nrf_ble_gatt_eff_mtu_get (nrf_ble_gatt_t *p_gatt, uint16_t conn_handle)
	Function for getting the current ATT_MTU size for a connection handle. More...

Detailed Description

Module for negotiating and keeping track of the maximum ATT_MTU size.

Macro Definition Documentation

#define NRF_BLE_CENTRAL_LINK_COUNT   1

Default maximum number of peripheral links.

To override this default value, define the maximum number of peripheral links in your module.

#define NRF_BLE_GATT_MAX_MTU_SIZE   GATT_MTU_SIZE_DEFAULT

Default maximum ATT_MTU size.

This define specifies a fallback value for the case where NRF_BLE_GATT_MAX_MTU_SIZE is not set in the GATT module configuration.

#define NRF_BLE_PERIPHERAL_LINK_COUNT   1

Default maximum number of central links.

To override this default value, define the maximum number of central links in your module.

Typedef Documentation

typedef void(* nrf_ble_gatt_evt_handler_t)(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t *p_evt)

GATT module event handler type.

The GATT module calls a function of this type when the ATT_MTU value is changed.

Function Documentation

ret_code_t nrf_ble_gatt_att_mtu_central_set	(	nrf_ble_gatt_t *	p_gatt,
		uint16_t	desired_mtu
	)

Function for setting the ATT_MTU size for the next link that is established as central.

Parameters

[in]	p_gatt	Pointer to the GATT structure.
[in]	desired_mtu	Requested ATT_MTU size.

Return values

NRF_SUCCESS	If the operation was successful.
NRF_ERROR_NULL	If the pointer to p_gatt is NULL.
NRF_ERROR_INVALID_PARAM	If the size of desired_mtu is bigger than NRF_BLE_GATT_MAX_MTU_SIZE or smaller than GATT_MTU_SIZE_DEFAULT.

ret_code_t nrf_ble_gatt_att_mtu_periph_set	(	nrf_ble_gatt_t *	p_gatt,
		uint16_t	desired_mtu
	)

Function for setting the ATT_MTU size for the next link that is established as peripheral.

Parameters

[in]	p_gatt	Pointer to the GATT structure.
[in]	desired_mtu	Requested ATT_MTU size.

Return values

NRF_SUCCESS	If the operation was successful.
NRF_ERROR_NULL	If the pointer to p_gatt is NULL.
NRF_ERROR_INVALID_PARAM	If the size of desired_mtu is bigger than NRF_BLE_GATT_MAX_MTU_SIZE or smaller than GATT_MTU_SIZE_DEFAULT.

uint16_t nrf_ble_gatt_eff_mtu_get	(	nrf_ble_gatt_t *	p_gatt,
		uint16_t	conn_handle
	)

Function for getting the current ATT_MTU size for a connection handle.

Parameters

[in]	p_gatt	Pointer to the GATT structure.
[in]	conn_handle	Connection handle of the link.

Returns

ATT_MTU size for the given link.

Return values

0	If the pointer to p_gatt is NULL or if conn_handle is larger than the supported maximum number of connections.

ret_code_t nrf_ble_gatt_init	(	nrf_ble_gatt_t *	p_gatt,
		nrf_ble_gatt_evt_handler_t	evt_handler
	)

Function for initializing the GATT module.

Parameters

[in]	evt_handler	Event handler.
[out]	p_gatt	Pointer to the GATT structure.

Return values

NRF_SUCCESS	If the operation was successful.
NRF_ERROR_NULL	If the pointer to p_gatt is NULL.

void nrf_ble_gatt_on_ble_evt	(	nrf_ble_gatt_t *	p_gatt,
		ble_evt_t *	p_ble_evt
	)

Function for handling BLE stack events.

This function handles all events from the BLE stack that are of interest to the GATT module.

Parameters

[in]	p_gatt	Pointer to the GATT structure.
[in]	p_ble_evt	Event received from the BLE stack.