iMAC connects automatically after disconnecting a BLE device

RE: iMAC connects automatically after disconnecting a BLE device

Yury Morgunov — Mon, 02 Mar 2020 04:59:02 GMT

This problem also manifests itself on nrf51422 chips. With test firmware SDK 12.3.
Can someone reproduce this problem?

RE: iMAC connects automatically after disconnecting a BLE device

Yury Morgunov — Fri, 28 Feb 2020 02:57:38 GMT

What if the problem is in the connection settings?

Maybe the device is too tempting to connect?

#define FIRST_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(5000)  
#define NEXT_CONN_PARAMS_UPDATE_DELAY    APP_TIMER_TICKS(30000) 
#define MAX_CONN_PARAMS_UPDATE_COUNT     3                     

static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}

static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = NULL;
    cp_init.error_handler                  = conn_params_error_handler;
    
    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}

RE: iMAC connects automatically after disconnecting a BLE device

Yury Morgunov — Fri, 28 Feb 2020 02:38:36 GMT

I wrote packets through nrf sniffer in wireshark.: devzone.nordicsemi.com/.../0027.reconnect-problem.pcapng
Performed the following actions:
Connected to the device via iMAC.
Clicked disconnect - the device was disconnected then connected.
Clicked disconnect again - same thing

To exclude no understanding attached photo buttons

In this case, the purchased ble keyboard turns off normally

RE: iMAC connects automatically after disconnecting a BLE device

Susheel Nuguru — Thu, 27 Feb 2020 13:05:37 GMT

It is the peer device, that decides to connect/or not to connect to the advertisement from an already bonded device. I do not think the library from our SDK initiates the connection. Can you sniff the air packets to see who initiates the connection?

RE: iMAC connects automatically after disconnecting a BLE device

Yury Morgunov — Thu, 27 Feb 2020 12:54:44 GMT

I do not need to remove the connection between devices.
I need that after clicking disconnect it does not connect automatically until I click connect.
Communication between devices should remain

RE: iMAC connects automatically after disconnecting a BLE device

Susheel Nuguru — Thu, 27 Feb 2020 12:50:08 GMT

Hi,

setting the advertising directed state to disable will not delete the bond information for the system.

If you do not want the device to be reconnected, then either delete the bond data or change the device address so that the peer sees your device as a different one than the one bonded