RE: BLE & BT 5.0 ble_app_uart

Edvin — Fri, 14 Dec 2018 14:37:32 GMT

Hello,

First, I'll just mention that SDK 15.1.0 was pulled, so I recommend that you download SDK15.2.0. There are just a few bug-fixes, so you shouldn't have to change anything else.

All BLE links are by default created on 1M phy, so you can request a phy change. Just add this at the end of the BLE_GAP_EVT_CONNECTED event:


ble_gap_phys_t const phys =
{
    .rx_phys = BLE_GAP_PHY_2MBPS,
    .tx_phys = BLE_GAP_PHY_2MBPS,
};
err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
APP_ERROR_CHECK(err_code);

It takes a couple of seconds, but you can look after the BLE_GAP_EVT_PHY_UPDATE event (you can add this event to your ble_evt_handler, and print NRF_LOG_INFO("Phy updated"); in the event.

The MTU is set in gatt_init, so you shouldn't need to touch BLE_GATT_ATT_MTU_DEFAULT.

/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE); //NRF_SDH_BLE_GATT_MAX_MTU_SIZE == 247
    APP_ERROR_CHECK(err_code);
}

You can disable the UART printing on the central device (or both). Just comment out the app_uart_put() functions. These are definitely a bottleneck when you are testing throughput.

Best regards,

Edvin