nRF52840 and s340: can BLE and ANT+ be used to send data at the same time?

RE: nRF52840 and s340: can BLE and ANT+ be used to send data at the same time?

robca — Thu, 05 Mar 2020 17:17:25 GMT

Thanks Kenneth,

I was using the same code as in the ble_ant_app_hrm_pca10056_s340 example, as per below

Since all the examples I saw were asserting on NRF_ERROR_BUSY returned by sd_ble_gap_phy_update(), I was not sure if it was safe to retry.

I will implement appropriate retry logic, thanks for confirming that what I'm going is safe (also, re-reading more of the softdevice documentation, and the softdevice is already written to allow BLE and ANT+ to coexist, the cocnurrent multiprotocol/radio timeslot is only for proprietary implementations)

Do you know why there is no S340 documentation, outside of the list of APIs? All other softdevices are much better documented

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code = NRF_SUCCESS;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected");
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}

RE: nRF52840 and s340: can BLE and ANT+ be used to send data at the same time?

Kenneth — Thu, 05 Mar 2020 09:22:39 GMT

Hi,

NRF_ERROR_BUSY is not really a critical error that you need to assert on. It basically means busy, try again later (for instance due to an on-going procedure that need to complete before you can execute this one). I don't know which softdevice call you are trying that is returning this error, but my suggestion is to for instance try again in a while loop (as it seems you are doing) or start an app_timer single shot that try again for instance in 100ms.

Best regards,
Kenneth

RE: nRF52840 and s340: can BLE and ANT+ be used to send data at the same time?

robca — Tue, 03 Mar 2020 22:03:55 GMT

Quick update. I temporarily worked around the issue adding

while (sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys) != NRF_SUCCESS) 
{}

in ble_evt_handler(), as per below. I'm not sure, though, if it's an acceptable workaround, and the ble_ant_app_hrm_pca10056_s340 example doesn't seem to need this workaround (granted, it looks as if in that case the ANT+ stack is not actively used while waiting for the BLE connection)

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            while (sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys) != NRF_SUCCESS)
            {}
        } break;

After this hack, everything seems to work well, and I can receive BLE and ANT+ data at the same time

Any recommendations on how safe the hack is? I'm still struggling to understand how BLE and ANT+ coexist in S340