The Buttonless DFU Template Application is not working on a custom board

[Vu]

Hi,

I am currently working on a custom product that uses module BMD-300 from u-blox, which has nrf52382 chip in it. My application works fine and now I want to integrate the Secure DFU function into it. I programmed the board with the DFU test image sd_s132_bootloader_buttonless_with_setting_page_dfu_secure_ble_debug_without_bonds.hex but I could not see it advertising when I scan for devices on nrf Connect. Does anyone know what problem could cause it to not advertising? I am using sdk v15.0.0.

Thank you in advance.

[Vu]

Here is where it stops when I try program the device through DFU. If I hit "Connect", it will reconnect to the device like normal and I have to restart the whole process.

[Edvin]

Do you know whether it is the bootloader or the application that freezes? Try monitoring the log on both.

Try to monitor the log in the _debug bootloader project. What does it say? Did it change after you changed the LFCLOCK settings?

[Vu]

Update: So now everything works with nRF Connect on iOS. I can get the device to go into DFU mode and reprogram it.

The problem still is that it freezes after connected to nRF Connect on PC. I don't think this problem is related to the DFU function as I haven't even tried to go into DFU mode after the connection. What is the difference between nRF Connect on iOS vs on PC?

[Edvin]

Can you please let me know what changes you did when everything suddenly started working? Perhaps it is related to the new issues.

Whenever something works from one device and not another, I suspect bonding issues. Did you enable bonding in the bootloader, or do you use bonding in your application?

Again, can you try to debug both the application and the bootloader? Does any of the logs give any indications that something is wrong?

Have you tried to capture a sniffer trace of the BLE connection?

[Vu]

I debug the application with IAR. Here is the message I got:

"The processor has escalated a configurable-priority exception to HardFault. Exception occured at PC = 0x2dd22, LR = 0x2dd71"

In disassembly, 0x2dd22 and 0x2dd71 are in ble_conn_params.c. 0x2dd22 is at line 4 of this function:

static bool send_update_request(uint16_t conn_handle, ble_gap_conn_params_t * p_new_conn_params)
{
    ret_code_t err_code;
    err_code = sd_ble_gap_conn_param_update(conn_handle, p_new_conn_params);
    if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY)) // NRF_ERROR_BUSY means another conn_param_update request is pending.
    {
        send_error_evt(err_code);
    }
    return (err_code == NRF_SUCCESS);
}

    

and 0x2dd71 is at line 10 of this function:

static void update_timeout_handler(void * p_context)
{
    uint32_t                     conn_handle = (uint32_t)p_context;
    ble_conn_params_instance_t * p_instance  = instance_get(conn_handle);
    if (p_instance != NULL)
    {
        // Check if we have reached the maximum number of attempts
        if (p_instance->update_count < m_conn_params_config.max_conn_params_update_count)
        {
            bool update_sent = send_update_request(conn_handle, &p_instance->preferred_conn_params);
            if (update_sent)
            {
                p_instance->update_count++;
            }
        }
        else
        {
            p_instance->update_count = 0;

            // Negotiation failed, disconnect automatically if this has been configured
            if (m_conn_params_config.disconnect_on_fail)
            {
                ret_code_t err_code;
                err_code = sd_ble_gap_disconnect(conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_INVALID_STATE)) // NRF_ERROR_INVALID_STATE means disconnect is already in progress.
                {
                    send_error_evt(err_code);
                }
            }
            // Notify the application that the procedure has failed
            if (m_conn_params_config.evt_handler != NULL)
            {
                ble_conn_params_evt_t evt;
                evt.evt_type = BLE_CONN_PARAMS_EVT_FAILED;
                evt.conn_handle = conn_handle;
                m_conn_params_config.evt_handler(&evt);
            }
        }
    }
}

From the log I can see that it happened after the BLE_GAP_EVT_DATA_LENGTH_UPDATE event.