nRF52 DK ble_app_cscs example "Change MTU size issue"

[silverzero]

Hi I want to change MTU size cuz I want to send  more

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sdk_config.h

// <i> Requested BLE GAP data length to be negotiated.

#ifndef NRF_SDH_BLE_GAP_DATA_LENGTH

#define NRF_SDH_BLE_GAP_DATA_LENGTH 247

#endif

// <o> NRF_SDH_BLE_PERIPHERAL_LINK_COUNT - Maximum number of peripheral links.

#ifndef NRF_SDH_BLE_PERIPHERAL_LINK_COUNT

#define NRF_SDH_BLE_PERIPHERAL_LINK_COUNT 1

#endif

// <o> NRF_SDH_BLE_CENTRAL_LINK_COUNT - Maximum number of central links.

#ifndef NRF_SDH_BLE_CENTRAL_LINK_COUNT

#define NRF_SDH_BLE_CENTRAL_LINK_COUNT 0

#endif

// <o> NRF_SDH_BLE_TOTAL_LINK_COUNT - Total link count.

// <i> Maximum number of total concurrent connections using the default configuration.

#ifndef NRF_SDH_BLE_TOTAL_LINK_COUNT

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sdk_config.h
// <i> Requested BLE GAP data length to be negotiated.

#ifndef NRF_SDH_BLE_GAP_DATA_LENGTH
#define NRF_SDH_BLE_GAP_DATA_LENGTH 247
#endif

// <o> NRF_SDH_BLE_PERIPHERAL_LINK_COUNT - Maximum number of peripheral links. 
#ifndef NRF_SDH_BLE_PERIPHERAL_LINK_COUNT
#define NRF_SDH_BLE_PERIPHERAL_LINK_COUNT 1
#endif

// <o> NRF_SDH_BLE_CENTRAL_LINK_COUNT - Maximum number of central links. 
#ifndef NRF_SDH_BLE_CENTRAL_LINK_COUNT
#define NRF_SDH_BLE_CENTRAL_LINK_COUNT 0
#endif

// <o> NRF_SDH_BLE_TOTAL_LINK_COUNT - Total link count. 
// <i> Maximum number of total concurrent connections using the default configuration.

#ifndef NRF_SDH_BLE_TOTAL_LINK_COUNT
#define NRF_SDH_BLE_TOTAL_LINK_COUNT 1
#endif

// <o> NRF_SDH_BLE_GAP_EVENT_LENGTH - GAP event length. 
// <i> The time set aside for this connection on every connection interval in 1.25 ms units.

#ifndef NRF_SDH_BLE_GAP_EVENT_LENGTH
#define NRF_SDH_BLE_GAP_EVENT_LENGTH 260
#endif

// <o> NRF_SDH_BLE_GATT_MAX_MTU_SIZE - Static maximum MTU size. 
#ifndef NRF_SDH_BLE_GATT_MAX_MTU_SIZE
#define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 247
#endif

// <o> NRF_SDH_BLE_GATTS_ATTR_TAB_SIZE - Attribute Table size in bytes. The size must be a multiple of 4. 
#ifndef NRF_SDH_BLE_GATTS_ATTR_TAB_SIZE
#define NRF_SDH_BLE_GATTS_ATTR_TAB_SIZE 1408
#endif

// <o> NRF_SDH_BLE_VS_UUID_COUNT - The number of vendor-specific UUIDs. 
#ifndef NRF_SDH_BLE_VS_UUID_COUNT
#define NRF_SDH_BLE_VS_UUID_COUNT 0
#endif

// <q> NRF_SDH_BLE_SERVICE_CHANGED  - Include the Service Changed characteristic in the Attribute Table.
 

#ifndef NRF_SDH_BLE_SERVICE_CHANGED
#define NRF_SDH_BLE_SERVICE_CHANGED 0
#endif












/////////////////ble_cscs.c
#define MAX_CSCM_LEN (BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH)









///////////////ble_gatt.h

/** @addtogroup BLE_GATT_DEFINES Defines
 * @{ */

/** @brief Default ATT MTU, in bytes. */
#define BLE_GATT_ATT_MTU_DEFAULT          23

/**@brief Invalid Attribute Handle. */
#define BLE_GATT_HANDLE_INVALID            0x0000

/**@brief First Attribute Handle. */
#define BLE_GATT_HANDLE_START              0x0001

/**@brief Last Attribute Handle. */
#define BLE_GATT_HANDLE_END                0xFFFF

/** @defgroup BLE_GATT_TIMEOUT_SOURCES GATT Timeout sources
 * @{ */
#define BLE_GATT_TIMEOUT_SRC_PROTOCOL      0x00  /**< ATT Protocol timeout. */
/** @} */

30bytes.

Now I'd identified only 20 bytes of data being transferred.

I changed the MTU SIZE, but it does not become advertising. This is my code. What parts do I have to change?

Or, can't I change the MTU size in the cscs example?