Soft Device Scan Parms not being set correctly from struct

[inspiringdev123]

I set my scan params in the following init code.

 

/**@brief Function for initializing the scanning and setting the filters.
 */
static void scan_init(void)
{   
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;
    ble_gap_scan_params_t const m_scan_param =
    {
      .active        = 0x01,
      .interval      = NRF_BLE_SCAN_SCAN_INTERVAL,
      .window        = NRF_BLE_SCAN_SCAN_WINDOW,
      .filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL, //BLE_GAP_SCAN_FP_WHITELIST,
      .timeout       = 0,
      .scan_phys     = BLE_GAP_PHY_1MBPS,
    };

    memset(&init_scan, 0, sizeof(init_scan));
    /**< Scan parameters requested for scanning and connection. */
    init_scan.p_scan_param     = &m_scan_param;
    init_scan.connect_if_match = false;
    init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);

}

The interval and scan window are both set to 100. However, when I watch the variables in debug mode, the variables are as follows. 

Any idea how they are being set so wrong? No other references to these variables in the code anywhere except here and when I start scanning following the advertising period ending (60 seconds).

[tesc]

Hi,

Any idea how they are being set so wrong? No other references to these variables in the code anywhere except here and when I start scanning following the advertising period ending (60 seconds).

You should use a static variable for the ble_gap_scan_params_t structure used for the p_scan_param pointer in the p_init argument to nrf_ble_scan_init().

In your implementation, the variable is not static, so when your function scan_init() returns the pointer points to a location in stack memory that will later be overwritten by the local variables of other functions.

For an example of working initialization with custom scan parameters, see the Advanced initialization section of the Scanning Module documentation.

Regards,
Terje

[inspiringdev123]

I changed it to a static and still no luck. I copied over the strict from the working example. 

[inspiringdev123]

tesc I advertise with my module for 1 minute in the beginning of the program. Could this possibly be affecting the scanning parameters? I was able to set the parameters successfully in a standalone program, but are now having issues when merging with existing advertising code. 

[tesc]

Hi,

Are you sure that you are looking at the correct struct, in the debug view?

What are the values of the parameters you set? (NRF_BLE_SCAN_SCAN_INTERVAL, NRF_BLE_SCAN_SCAN_WINDOW, etc.)

Interval and window of 0x6401 and 0x6400 look a bit suspicious to me, typically one would set them to the same if one wants 100 % duty cycle.

Do you see the same values when using the code example from the documentation, as you did with your values earlier?

Regards,
Terje

[inspiringdev123]

Here are how they are set in my sdk config file.

That seemed very suspicious to me as well since they were 0x0064 in my other code. 

[inspiringdev123]

This is from the ble_app_multilink_central example from sdk17.0.2.