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?

[fatih]

#define NRF_BLE_SCAN_SCAN_INTERVAL 10

#define NRF_BLE_SCAN_SCAN_DURATION 0

#define NRF_BLE_SCAN_SCAN_WINDOW 20

These are the values I have right now. I did not use nrf_ble_scan_connect_with_target as it seems to do exactly what I'm doing here. But I'm absolutely using the scan functionality, just not the connect one.

[Simonr]

Thank you, these values should be okay, although rather low in my opinion, what happens if you set the scan interval and window to the same value? That should make sure that the device scans 100% of the time, as the central will scan for SCAN_WINDOW time, every SCAN_INTERVAL interval.

Next, what connection parameters are you using (min/max_conn_interval, slave_latency, conn_sup_timeout)? The valid parameters here should be stated in BLE_GAP_CP_LIMITS. 

Best regards,

Simon

[lobaro-theo]

Hello,

had the same issue. For me setting SCAN_WINDOW and SCAN_INTERVAL to the same value, e.g. (160 * UNIT_0_625_MS), made it work. With Window (80*...) and Interval (160*...) I got the same invalid param error as fatih with s132 V7.2.0.

So thanks Simonr for pointing in the right direction. 

Theo