multilink [ble_app_uart] - [ble_app_multilink_central](2)

[yokokawa]

The sample program uses "nRF5_SDK_15.0.0_a53641a".

Hardware uses Taiyo Yuden's "EYSHSNZWZ"

In addition, we use a sample of [ble_app_uart] and [ble_app_multilink_central] to create a program that communicates uart data in multiple ways.

Please tell me about the error of the central side program with multi communication.

One peripheral is connected to the central, and after executing "scan_start ()" again, a 0x08 error will occur, please tell me the cause and measures.

Attach flag information below.
 That's all, thank you.

[AndreasF]

Hi.

If you look at the API for the SoftDevice call made in the function scan_start(void), that SoftDevice call is sd_ble_gap_scan_start():

/**@brief Start or continue scanning (GAP Discovery procedure, Observer Procedure).
 *
 * @note    A call to this function will require the application to keep the memory pointed by
 *          p_adv_report_buffer alive until the buffer is released. The buffer is released when the scanner is stopped
 *          or when this function is called with another buffer.
 *
 * @note    The scanner will automatically stop in the following cases:
 *           - @ref sd_ble_gap_scan_stop is called.
 *           - @ref sd_ble_gap_connect is called.
 *           - A @ref BLE_GAP_EVT_TIMEOUT with source set to @ref BLE_GAP_TIMEOUT_SRC_SCAN is received.
 *           - When a @ref BLE_GAP_EVT_ADV_REPORT event is received and @ref ble_gap_adv_report_type_t::status is not set to
 *             @ref BLE_GAP_ADV_DATA_STATUS_INCOMPLETE_MORE_DATA. In this case scanning is only paused to let the application
 *             access received data. The application must call this function to continue scanning, or call @ref sd_ble_gap_scan_stop
 *             to stop scanning.
 *
 * @note    If a @ref BLE_GAP_EVT_ADV_REPORT event is received with @ref ble_gap_adv_report_type_t::status set to
 *          @ref BLE_GAP_ADV_DATA_STATUS_INCOMPLETE_MORE_DATA, the scanner will continue scanning, and the application will
 *          receive more reports from this advertising event. The following reports will include the old and new received data.
 *          The application can stop the scanner from receiving more packets from this advertising event by calling this function.
 *          This might be useful when receiving data from extended advertising events where @ref ble_gap_evt_adv_report_t::aux_pointer
 *          is large.
 *
 * @events
 * @event{@ref BLE_GAP_EVT_ADV_REPORT, An advertising or scan response packet has been received.}
 * @event{@ref BLE_GAP_EVT_TIMEOUT, Scanner has timed out.}
 * @endevents
 *
 * @mscs
 * @mmsc{@ref BLE_GAP_SCAN_MSC}
 * @mmsc{@ref BLE_GAP_WL_SHARE_MSC}
 * @endmscs
 *
 * @param[in] p_scan_params       Pointer to scan parameters structure. When this function is used to continue
 *                                scanning, this parameter must be NULL.
 * @param[in] p_adv_report_buffer Pointer to buffer used to store incoming advertising data.
 *                                The memory pointed to should be kept alive until the scanning is stopped.
 *                                See @ref BLE_GAP_SCAN_BUFFER_SIZE for minimum and maximum buffer size.
 *                                If the scanner receives advertising data larger than can be stored in the buffer,
 *                                a @ref BLE_GAP_EVT_ADV_REPORT will be raised with @ref ble_gap_adv_report_type_t::status
 *                                set to @ref BLE_GAP_ADV_DATA_STATUS_INCOMPLETE_TRUNCATED.
 *
 * @retval ::NRF_SUCCESS Successfully initiated scanning procedure.
 * @retval ::NRF_ERROR_INVALID_ADDR Invalid pointer supplied.
 * @retval ::NRF_ERROR_INVALID_STATE Invalid state to perform operation. Either:
 *                                   - Scanning is already ongoing and p_scan_params was not NULL
 *                                   - Scanning is not running and p_scan_params was NULL.
 *                                   - The scanner has timed out when this function is called to continue scanning.
 * @retval ::NRF_ERROR_INVALID_PARAM Invalid parameter(s) supplied. See @ref ble_gap_scan_params_t.
 * @retval ::NRF_ERROR_NOT_SUPPORTED Unsupported parameters supplied. See @ref ble_gap_scan_params_t.
 * @retval ::NRF_ERROR_INVALID_LENGTH The provided buffer length is invalid. See @ref BLE_GAP_SCAN_BUFFER_MIN.
 * @retval ::NRF_ERROR_RESOURCES Not enough BLE role slots available.
 *                               Stop one or more currently active roles (Central, Peripheral or Broadcaster) and try again
 * @retval ::NRF_ERROR_NOT_SUPPORTED Unsupported PHYs supplied to the call.
 */
SVCALL(SD_BLE_GAP_SCAN_START, uint32_t, sd_ble_gap_scan_start(ble_gap_scan_params_t const *p_scan_params, ble_data_t const * p_adv_report_buffer));

And check the error codes in nrf_error.h, you can find that error code 8 is NRF_ERROR_INVALID_STATE.

NRF_ERROR_INVALID_STATE Invalid state to perform operation. This can be cause by one of the following reasons:
                                  - Scanning is already ongoing and p_scan_params was not NULL
                                  - Scanning is not running and p_scan_params was NULL.
                                  - The scanner has timed out when this function is called to continue scanning.

So, maybe you are already scanning? Or have given wrong input parameters to the API call, or the scanner has timed out?

Best regards.

Andreas