SDK13 NRF_ERROR_NO_MEM at sd_ble_gatts_characteristic_add()

[matthk]

Hello, when starting a new project I took the nice Heart-Rate-Example which works fine at my PCA10040. Then I started to add services and characteristics by copying and adapting the HRS - I know that I will have to declare them as vendor specific services and characteristics - this is not already done. One new service with 11 characteristics works fine, but adding a second will lead to a NRF_ERROR_NO_MEM as return value at the sd_ble_gatts_characteristic_add() function and then a Reset is executed. In one post in this forum I saw that adding

memset(&ble_cfg, 0, sizeof(ble_cfg));
ble_cfg.gatts_cfg.attr_tab_size.attr_tab_size = BLE_GATTS_ATTR_TAB_SIZE_MIN;
err_code = sd_ble_cfg_set(BLE_GATTS_CFG_ATTR_TAB_SIZE, &ble_cfg, ram_start);
APP_ERROR_CHECK(err_code);

could help, but in my project this is not the case. I tried already various RAM-settings in the linker configuration file, but all without success. What can I do next?

[matthk]

Hi Hung Bui, my ble_stack_init() looks now like this:

static void ble_stack_init(void)
{
    ret_code_t err_code;

    nrf_clock_lf_cfg_t clock_lf_cfg = NRF_CLOCK_LFCLKSRC;

    // Initialize the SoftDevice handler module.
    SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg, NULL);

    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = softdevice_app_ram_start_get(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Overwrite some of the default configurations for the BLE stack.
    ble_cfg_t ble_cfg;

    // Configure the number of custom UUIDS.
    memset(&ble_cfg, 0, sizeof(ble_cfg));
    ble_cfg.common_cfg.vs_uuid_cfg.vs_uuid_count = 0;
    err_code = sd_ble_cfg_set(BLE_COMMON_CFG_VS_UUID, &ble_cfg, ram_start);
    APP_ERROR_CHECK(err_code);

    // Configure the maximum number of connections.
    memset(&ble_cfg, 0, sizeof(ble_cfg));
    ble_cfg.gap_cfg.role_count_cfg.periph_role_count  = BLE_GAP_ROLE_COUNT_PERIPH_DEFAULT;
    ble_cfg.gap_cfg.role_count_cfg.central_role_count = 0;
    ble_cfg.gap_cfg.role_count_cfg.central_sec_count  = 0;
    err_code = sd_ble_cfg_set(BLE_GAP_CFG_ROLE_COUNT, &ble_cfg, ram_start);
    APP_ERROR_CHECK(err_code);

    // Configure the maximum ATT MTU.
    memset(&ble_cfg, 0x00, sizeof(ble_cfg));
    ble_cfg.conn_cfg.conn_cfg_tag                 = CONN_CFG_TAG;
    ble_cfg.conn_cfg.params.gatt_conn_cfg.att_mtu = NRF_BLE_GATT_MAX_MTU_SIZE;
    err_code = sd_ble_cfg_set(BLE_CONN_CFG_GATT, &ble_cfg, ram_start);
    APP_ERROR_CHECK(err_code);

    // Configure the maximum event length.
    memset(&ble_cfg, 0x00, sizeof(ble_cfg));
    ble_cfg.conn_cfg.conn_cfg_tag                     = CONN_CFG_TAG;
    ble_cfg.conn_cfg.params.gap_conn_cfg.event_length = 320;
    ble_cfg.conn_cfg.params.gap_conn_cfg.conn_count   = BLE_GAP_CONN_COUNT_DEFAULT;
    err_code = sd_ble_cfg_set(BLE_CONN_CFG_GAP, &ble_cfg, ram_start);
    APP_ERROR_CHECK(err_code);

#ifndef BEACON_TEST
    // aus Beacon Example
    memset(&ble_cfg, 0, sizeof(ble_cfg));
//    ble_cfg.gatts_cfg.attr_tab_size.attr_tab_size = BLE_GATTS_ATTR_TAB_SIZE_MIN;
    ble_cfg.gatts_cfg.attr_tab_size.attr_tab_size = BLE_GATTS_ATTR_TAB_SIZE_DEFAULT;
    err_code = sd_ble_cfg_set(BLE_GATTS_CFG_ATTR_TAB_SIZE, &ble_cfg, ram_start);
    APP_ERROR_CHECK(err_code);
#endif

    // Enable BLE stack.
    err_code = softdevice_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register with the SoftDevice handler module for BLE events.
    err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
    APP_ERROR_CHECK(err_code);

    // Register with the SoftDevice handler module for BLE events.
    err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
    APP_ERROR_CHECK(err_code);
}

The constant BLE_GATTS_ATTR_TAB_SIZE_MIN has the value 23 and BLE_GATTS_ATTR_TAB_SIZE_DEFAULT is defined with 1408.

Nothing changes by changing the attribute value; it works well with a services_init() with the following services:

DTHAD (my own, but not already defined with a vendor-specific UUID (0x2B30) and 11 characteristics (starting from 0x2B31...) Heart rate service HRS Battery service BAS Device Information Service DIS

When I add another service DTHL (from my own, UUID 0x2B50 with some characteristics starting at 0x2B51..., no vendor-specific UUIDs) directly after the DTHAD service the last service in this list - in this case the DIS service - I get error code 4 at ble_dis_init()...

When I take away the DTHL service everything becomes fine...

Now I increased the value for BLE_GATTS_ATTR_TAB_SIZE_DEFAULT to 2408 and now with 4 self-created services it works!

Can you tell me to which value I can increase this constant?

Thanks in advance,

Matthias

[Hung Bui]

Hi Matthias, Next time , please edit you question and add your code in, not as an Answer. I don't think there would be any issue increasing the size of the attribute table as you did (to 2408), but don't modify BLE_GATTS_ATTR_TAB_SIZE_DEFAULT , just change ble_cfg.gatts_cfg.attr_tab_size.attr_tab_size = 2048 for example.

The only draw back is you have less RAM for the application.

Again, I don't really see the point why you need 11 characteristics (and then 2 same service with total 22 characteristics). This will make the service discovery procedure take a lot of time, causing delay when you connecting and start data exchanging.