Problem with direct advertising

[AndrzejB]

Hi. I need to use direct advertising option in my application to minimize the time needed to establish the connection. Firstly, I set up the connection during "normal" fast connectable indirect advertising, where central and peripheral devices are being paired and bonded together with the help of device manager and the address of central is captured for later direct reconnection (I skip the issue of whitelist on central at this moment). Both of them (I mean central and peripheral devices) are programmed in nrf51822, and these parts of programs work properly. I think so, because I check device manager events on peripheral device and after power cycling both of them (central and peripheral devices) I get an event DM_EVT_SECURITY_SETUP_COMPLETE during first connection. After bonding they are disconnected and I’m trying to reconnect them later. Peripheral device starts to advertise to address that was collected previously and at this moment I have the problem, because connection cannot be established. What's more, if I change the advertising type to connectable indirect advertising, the connection is established pretty quickly, but that is only a way around, not a solution.

sec_params for device manager module in both, central and peripheral are the same:

SEC_PARAM_BOND             1                                  
SEC_PARAM_MITM             0                                  
SEC_PARAM_LESC             0
SEC_PARAM_KEYPRESS         0                                 
SEC_PARAM_IO_CAPABILITIES  BLE_GAP_IO_CAPS_NONE              
SEC_PARAM_OOB              0                                  
SEC_PARAM_MIN_KEY_SIZE     7                                  
SEC_PARAM_MAX_KEY_SIZE     16

I collect a peer address in on_ble_evt when BLE_GAP_EVT_CONNECTED event has occurred:

addr = p_ble_evt->evt.gap_evt.params.connected.peer_addr;

I display that address and it is correct, I pass it on to SoftDevice in Little Endian notation in ble_advertising_peer_addr_reply function. I use SDK 11.0 and SD S130.

Sorry for long-winded boring essay, but I want to explain the problem and circumstances properly. Thanks for any help :).

[AndrzejB]

I start direct advertising like in sequence chart available in Infocenter for Advertising Module and I get the BLE_ADV_EVT_DIRECTED event. After timeout I start direct advertising in low duty cycle and I get BLE_ADV_EVT_DIRECTED_SLOW event.

[AndrzejB]

My central is based on ble_app_hrs_c example, where I removed both of services and inserted my own service (based on ble_lbs_c).

[Petter Myhre]

Are you getting BLE_GAP_EVT_ADV_REPORT events when you do directed advertising? If you are, have you made changes to the criterias for which device you want to connect to? The directed advertising packets only include the peripherals address and the centrals address, please see Bluetooth Core Specification 4.2, Volume 6, Part B, Section 2.3.1.2. So if you look for a UUID or something like that the central will not connect. If you get a BLE_GAP_EVT_ADV_REPORT event you should check if the type is BLE_GAP_ADV_TYPE_ADV_DIRECT_IND, and then you should check if the peripherals address matches with peer_addr and call sd_ble_gap_connect().

[AndrzejB]

I completely forgot there is no other info in Advertising Packet in direct mode. Now it's working in the way I want, Thanks