Beware that this post is related to an SDK in maintenance mode
More Info: Consider nRF Connect SDK for new designs
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Organizing my project code

Hello,

I am running an ble_app_uart example from SDK 17.1.0 in SES on my nRF52-DK.

As great example as it is, I find it a bit non-practical for further development so I wanted to organize it to suit my OCD a bit better. So I created separate .c/.h files in my project, and cut-and-pasted all the ble, nus and gatt related functionality over there. Please find the files in the attachment, including my main.c.

7838.MERS_BLE.h

/**
 * Source code for MERS related functions and variables 
 * Copyright (c) 2022 MarineEye
 * ---------------------------
 * Author: Pero Krivic
 * [email protected] 
 **/

#include "MERS_BLE.h"
#include "MERS_LoRaWAN.h"
#include "app_uart.h"


uint8_t key_cnt = 0;                   // Counter of the received keys (3rd key is split into two)
bool keys_received = false;            // Flag to indicate if all of the keys have been received


/**@brief Function for assert macro callback.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyse
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num    Line number of the failing ASSERT call.
 * @param[in] p_file_name File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name){
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
}

/**@brief Function for the GAP initialization.
 *
 * @details This function will set up all the necessary GAP (Generic Access Profile) parameters of
 *          the device. It also sets the permissions and appearance.
 */
static void gap_params_init(void){
    uint32_t                err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *) DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency     = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
void nrf_qwr_error_handler(uint32_t nrf_error){
    APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void){
    uint32_t           err_code;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
    APP_ERROR_CHECK(err_code);

    // Initialize NUS.
    memset(&nus_init, 0, sizeof(nus_init));

    nus_init.data_handler = nus_data_handler;

    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling the data from the Nordic UART Service.
 *
 * @details This function will process the data received from the Nordic UART BLE Service and send
 *          it to the UART module.
 *
 * @param[in] p_evt       Nordic UART Service event.
 */
/**@snippet [Handling the data received over BLE] */
static void nus_data_handler(ble_nus_evt_t * p_evt){

    if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;
        uint16_t length; 

        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
        
        /* Send data received from BLE to extract LoRaWAN keys from it */
        if (!keys_received) {
            mers_ble_nus_t mers_err_code = mers_ble_rx_data(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length, key_cnt);
            if (mers_err_code != BLE_NUS_BUFFER_SIZE_OK){
                NRF_LOG_ERROR("Wrong BLE data size");
                length = 7;
                err_code = ble_nus_data_send(&m_nus, "NOT OK", &length, m_conn_handle);
                APP_ERROR_CHECK(err_code);
            }
            else {
                NRF_LOG_INFO("Received key number %d", key_cnt + 1);
                length = 3;
                err_code = ble_nus_data_send(&m_nus, "OK", &length, m_conn_handle);
                APP_ERROR_CHECK(err_code);
                key_cnt++;
                if (key_cnt == 4)
                    keys_received = true;
            } 
        }        

        /* Print NUS data to the UART */
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            do
            {
                err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
    }

}
/**@snippet [Handling the data received over BLE] */




/**@brief Function for handling an event from the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module
 *          which are passed to the application.
 *
 * @note All this function does is to disconnect. This could have been done by simply setting
 *       the disconnect_on_fail config parameter, but instead we use the event handler
 *       mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt){
    uint32_t err_code;

    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
    }
}

/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt){
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
             err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_IDLE:
            // sleep_mode_enter();
            break;
        default:
            break;
    }
}


/**@brief Function for handling errors from the Connection Parameters module.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error){
    APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void){
    uint32_t               err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}



/**@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){
    uint32_t err_code;

    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");
            // LED indication will be changed when advertising starts.
            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_GAP_EVT_SEC_PARAMS_REQUEST:
            // Pairing not supported
            err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            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.
            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;
    }
}



/**@brief Function for initializing the Advertising functionality.
 */
static void advertising_init(void){
    uint32_t               err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance = false;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for the SoftDevice initialization.
 *
 * @details This function initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void){
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

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

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}


/**@brief Function for handling events from the GATT library. */
static void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt){
    if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                  p_gatt->att_mtu_desired_central,
                  p_gatt->att_mtu_desired_periph);
}


/**@brief Function for initializing the GATT library. 
*/
static 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);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for starting advertising.
 */
static void advertising_start(void){
    uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function to initialize everything related to BLE and NUS operation. 
*/
void mers_ble_init(void){
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
    advertising_start();
}

The example ble_app_uart is modified in that, all init functions are wrapped inside the single one called mers_ble_init(), and after the init it just calls for idle_state_handle(). Additionally, the nus-handler stores the data from the smartphone app into the flash. 

The code builds and links, but the application fails after flashing the chip. According to my debugging, the initialization works fine, bit it enters the hard fault in the main loop. I cant figure out what went wrong, since the project replicates the original example and builds successfully. Did I organize my library properly?

Best, 

W

EDIT: issue is solved.

The reason was that I didn't intend to use UART as an user input so I deleted the uart_event_handle, and set 

APP_UART_FIFO_INIT(&comm_params,
                   UART_RX_BUF_SIZE,
                   UART_TX_BUF_SIZE,
                   0,
                   APP_IRQ_PRIORITY_LOWEST,
                   err_code);

When I brought back the original hander function, and instantiated UART_FIFO properly, it worked again.

Anyways, the builder didn't mind having not uart handler, but the application wouldn't work without it. Why is that so? How can I disable UART events and keep the BLE functionality? Why do we need the uart_event_handle, when all it does is to send some characters to NUS?

Parents
  • Hi Pero

    Moving all the BLE functionality into a separate file makes a lot of sense. I usually do the same when I develop larger BLE projects. 

    Anyways, the builder didn't mind having not uart handler, but the application wouldn't work without it. Why is that so?

    It's good to hear you found the issue. I checked the code, and it seems there is no checking to make sure that the event handler is set or not. If you set it to 0 it will simply be accepted by the init function, and as soon as some UART activity occurs it will try to call the event handler at address 0 which will lead to a hardfault. 

    If you don't need the UART functionality you can simply remove it altogether, by removing the call to APP_UART_FIFO_INIT, and any other code referencing the app_uart library. 

    Best regards
    Torbjørn

  • Hello Torbjørn, thanks for the answer!

    Well truth to be told, I want to use UART, but not as the input. I want to print out some status messages using retargeted printf function, so I need APP_UART_FIFO_INIT. 

    soon as some UART activity occurs it will try to call the event handler at address 0 which will lead to a hardfault. 

    Okay this makes perfect sense. But I never typed anything on UART port, so the handler should never have been invoked. And in the debugger-mode, the printf commands are executed without invoking the handler, that is, without crashing into the hardfault. So, how does the handler get invoked if nothing has been entered at the UART port?

    Second problem with the handler:  I have left the handler inside my code, but I commented out most of the code inside of it. So it was basically a function that does nothing, but at least it wasn't at the address 0. However, the application still ended up in hardfault, leaving me to think it is something else that causes the crash. 

  • Hi Pero

    Pero Krivic said:
    Okay this makes perfect sense. But I never typed anything on UART port, so the handler should never have been invoked. And in the debugger-mode, the printf commands are executed without invoking the handler, that is, without crashing into the hardfault. So, how does the handler get invoked if nothing has been entered at the UART port?

    What was the state of the RX pin? 

    If the RX pin is low for a long time it will trigger a break condition in the UART peripheral, which will be registered as an error and forwarded to the interrupt handler. 

    You will also get events after sending UART data, but if you haven't sent anything in the code this should obviously not happen. 

    Pero Krivic said:
    Second problem with the handler:  I have left the handler inside my code, but I commented out most of the code inside of it. So it was basically a function that does nothing, but at least it wasn't at the address 0. However, the application still ended up in hardfault, leaving me to think it is something else that causes the crash. 

    Didn't you say that you solved the issue by bringing back the handler?

    To figure out what caused the hardfault you could try using the debugger, and see if you can trace which functions lead up to the hardfault by looking at the stack trace. 

    Best regards
    Torbjørn

Reply
  • Hi Pero

    Pero Krivic said:
    Okay this makes perfect sense. But I never typed anything on UART port, so the handler should never have been invoked. And in the debugger-mode, the printf commands are executed without invoking the handler, that is, without crashing into the hardfault. So, how does the handler get invoked if nothing has been entered at the UART port?

    What was the state of the RX pin? 

    If the RX pin is low for a long time it will trigger a break condition in the UART peripheral, which will be registered as an error and forwarded to the interrupt handler. 

    You will also get events after sending UART data, but if you haven't sent anything in the code this should obviously not happen. 

    Pero Krivic said:
    Second problem with the handler:  I have left the handler inside my code, but I commented out most of the code inside of it. So it was basically a function that does nothing, but at least it wasn't at the address 0. However, the application still ended up in hardfault, leaving me to think it is something else that causes the crash. 

    Didn't you say that you solved the issue by bringing back the handler?

    To figure out what caused the hardfault you could try using the debugger, and see if you can trace which functions lead up to the hardfault by looking at the stack trace. 

    Best regards
    Torbjørn

Children
Related