Packet Length Extension

RE: Packet Length Extension

veletron — Mon, 01 Oct 2018 10:08:25 GMT

Just a note for others. A DLE example has appeared in SDK V15.2 See here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.2.0%2Fble_sdk_app_att_mtu.html&cp=4_0_0_4_1_1_0

The DLE Update procedure for SoftDevice 132 V6.0.x can be found here: http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.s132.api.v6.0.0%2Fgroup___b_l_e___g_a_p___d_a_t_a___l_e_n_g_t_h___u_p_d_a_t_e___p_r_o_c_e_d_u_r_e___m_s_c.html&cp=2_3_1_1_0_2_1_3_6

Nigel

RE: Packet Length Extension

MartinBL — Wed, 26 Sep 2018 08:46:18 GMT

Hi,

Please refer to the Migration Document for S132 v6.0.0. It shows how to initiate (or respond to) a data length update procedure. You can find the document here: https://www.nordicsemi.com/eng/nordic/Products/nRF52-DK/S132-SD-v6/67250

RE: Packet Length Extension

veletron — Tue, 25 Sep 2018 14:06:46 GMT

Can nordic provide similar code for Soft Device 132 V6.0.0, SDK 15.0 ?? The code above does not work for this soft device as BLE_GAP_OPT_EXT_LEN is not defined and ext_len is not a member of gap_opt ?? I can find no exampled showing the correct way to do LE Length Extension...

Nigel

RE: Packet Length Extension

MartinBL — Fri, 06 Jul 2018 12:56:52 GMT

Hi,

To set the DLE to e.g. 50 you can use this code:

static void ble_stack_init(void)
{
    uint32_t err_code;

    nrf_clock_lf_cfg_t clock_lf_cfg = NRF_CLOCK_LFCLKSRC;

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

    ble_enable_params_t ble_enable_params;
    err_code = softdevice_enable_get_default_config(CENTRAL_LINK_COUNT,
                                                    PERIPHERAL_LINK_COUNT,
                                                    &ble_enable_params);
    APP_ERROR_CHECK(err_code);
    
    //Check the ram settings against the used number of links
    CHECK_RAM_START_ADDR(CENTRAL_LINK_COUNT,PERIPHERAL_LINK_COUNT);

    // Enable BLE stack.
#if (NRF_SD_BLE_API_VERSION == 3)
    ble_enable_params.gatt_enable_params.att_mtu = NRF_BLE_MAX_MTU_SIZE;
#endif
    err_code = softdevice_enable(&ble_enable_params);
    APP_ERROR_CHECK(err_code);

    // Subscribe for BLE events.
    err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
    APP_ERROR_CHECK(err_code);
    
    
    ble_opt_t gap_opt;
    gap_opt.gap_opt.ext_len.rxtx_max_pdu_payload_size = 54; //Example: set max length to 54bytes
    err_code = sd_ble_opt_set(BLE_GAP_OPT_EXT_LEN, &gap_opt);
    APP_ERROR_CHECK(err_code);
}

make sure to call sd_ble_opt_set() after you have enabled the Softdevice with softdevice_enable(). Otherwise you will get error 0x3001.

Also remember to increase the MTU size accordingly. In the BLE UART example you can do this by setting GATT_MTU_SIZE_DEFAULT in ble_gatt.h to the value you want.