How can set listening single channel on scanner?

[HANK]

My Environment

• Nrf52840
• SDK : nrf51_15.0.0
• soft device : s140
• Target  : Scanner (central)

I am trying to set GAP parameter for listening single channel that is from beacon to use single channel.

so. i have had to set GAP Parameter for scanning but it is not work.

how can i right approach ? Please let me know

Question

1. How can i set GAP parameter for listening single channel on central(scanner)

* Please let me example code or sample link , if you can

[MartinBL]

Hi,

Use the ble_gap_ch_mask_t structure in included in the ble_gap_scan_params_t structure and pass that to  sd_ble_gap_scan_start(). Take note of what the documentation says about the ble_gap_ch_mask_t structure:

* Every channel is represented with a bit positioned as per channel index defined in Bluetooth Core Specification v5.0,
* Vol 6, Part B, Section 1.4.1. The LSB contained in array element 0 represents channel index 0, and bit 39 represents
* channel index 39. If a bit is set to 1, the channel is not used.

To avoid scanning on channel 39 for example, you can modify m_scan_params in the ble_app_uart_c example like this:

/** @brief Parameters used when scanning. */
static ble_gap_scan_params_t const m_scan_params =
{
    .active   = 1,
    .interval = SCAN_INTERVAL,
    .window   = SCAN_WINDOW,
    .timeout          = SCAN_DURATION,
    .scan_phys        = BLE_GAP_PHY_1MBPS,
    .filter_policy    = BLE_GAP_SCAN_FP_ACCEPT_ALL,
    .channel_mask[4] = 0x80, // <- DON'T SCAN ON CHANNEL 39
};

[HANK]

Hi MartinBL,

it is work.

Thanks for your help