sd_ble_gap_connect: NRF_ERROR_INVALID_PARAM

[fatih]

Hello,

I'm trying to use `sd_ble_gap_connect` to connect to a peer I discovered using `nrf_ble_scan`.

nrf_ble_scan_init_t scan_init{};

scan_init.p_scan_param = &m_scan_param;

scan_init.conn_cfg_tag = 1;

nrf_ble_scan_init(&m_scan, &scan_init, scan_handler);

nrf_ble_scan_start(&m_scan);

Once I find a suitable peer, I do the following to connect to it:

nrf_ble_scan_stop();

res = sd_ble_gap_connect(&buf[last_seen].peer_addr,

&m_scan.scan_params,

&m_scan.conn_params,

m_scan.conn_cfg_tag);

if (res != NRF_SUCCESS) {

printf("sd_ble_gap_connect failed %s", nrf_strerror_get(res));

}

However, I always get 0x7 (invalid param) as my result. I checked my config and I have 5 central links configured. I tried passing NULL as the scan_params and conn_params to scan_init to use the default ones, but that did not help either.

Is there anything obvious that I'm missing?

[Simonr]

Hi

When sd_ble_gap_connect() returns NRF_ERROR_INVALID_PARAM that indicates that invalid parameter(s) has been supplied. Either invalid parameters in scan_params or conn_params have been supplied. A use of whitelist was requested but the whitelist has not been set (see sd_ble_gap_whitelist_set). Or the peer address was not present in the device identity list (see sd_ble_gap_device_identities_set).

Best regards,

Simon

[fatih]

Thanks for the reply! I'm not using the whitelist feature (I have BLE_GAP_SCAN_FP_ACCEPT_ALL set in the scan parameters). I'm getting the peer address from the scan, do I need to register the peer with the identity list?

[Simonr]

Can you show me a code snippet of your scan and conn_params, as I think you've used invalid parameters somewhere in there.

Only one device identity list can be used at a time and the list is shared between the BLE roles. The device identity list cannot be set if a BLE role is using the list.

 

Best regards,
Simon

[fatih]

static ble_gap_scan_params_t const m_scan_param = {

.active = 0x01,

.filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL,

.scan_phys = BLE_GAP_PHY_1MBPS,

.interval = NRF_BLE_SCAN_SCAN_INTERVAL,

.window = NRF_BLE_SCAN_SCAN_WINDOW,

.timeout = NRF_BLE_SCAN_SCAN_DURATION,

};

For conn_params, I'm just letting nrf_scan initialize it with the defaults. I did try with manual parameters as well but did not make a difference.

I feel like I'm missing what the identity list is for, and I do not set it up right now. Do I need it and if so, how should I do that? For instance, if I set connect_if_match in nrf_scan, how does that work?

[Simonr]

What are the values of the NRF_BLE_SCAN_SCAN_INTERVAL, NRF_BLE_SCAN_SCAN_WINDOW, and NRF_BLE_SCAN_SCAN_DURATION here?

Also, I'm interested in why you seem to be using your own custom version of the scan and connect functions. I would strongly recommend using something similar to the ble_app_hrs_c for instance where the nrf_ble_scan_connect_with_target() functions takes care of all these steps for you. Identity lists should not be necessary to use for BLE, so I don't think you should focus on that.

Best regards,

Simon