Always reconnect after peers deleted

[Borden]

Hi community,

I'm working on a BLE gamepad with custom board based on 51802 and s130, code modified from ble_app_hids_keyboard. The gamepad works like a charm on my Android phone, but I found there's a strange problem with reconnecting.

If I hold a specific button down while power up, the gamepad deletes all peers, just like the keyboard example does, but I don't know why, it still reconnect to my phone automatically, no matter whether peers were deleted. The only way to unbond to the phone is to delete bond from the phone side. I've tried several phones and several boards, all same results. Is that suppose to happen?

My pm init code is:

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

memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));
>
// Security parameters to be used for all security procedures.
sec_param.bond			= SEC_PARAM_BOND;
sec_param.mitm			= SEC_PARAM_MITM;
sec_param.lesc			= SEC_PARAM_LESC;
sec_param.keypress		= SEC_PARAM_KEYPRESS;
sec_param.io_caps		= SEC_PARAM_IO_CAPABILITIES;
sec_param.oob			= SEC_PARAM_OOB;
sec_param.min_key_size	= SEC_PARAM_MIN_KEY_SIZE;
sec_param.max_key_size	= SEC_PARAM_MAX_KEY_SIZE;
sec_param.kdist_own.enc	= 1;
sec_param.kdist_own.id	= 1;
sec_param.kdist_peer.enc = 1;
sec_param.kdist_peer.id	= 1;
err_code = pm_sec_params_set(&sec_param);
APP_ERROR_CHECK(err_code);

the adv init code is:

void advertising_init(void)
{
	uint32_t				err_code;
	uint8_t					adv_flags;
	ble_advdata_t			advdata;
	ble_adv_modes_config_t	options;
	// Build and set advertising data
	memset(&advdata, 0, sizeof(advdata));

	adv_flags						= BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
	advdata.name_type				= BLE_ADVDATA_FULL_NAME;
	advdata.include_appearance		= true;
	advdata.flags					= adv_flags;
	advdata.uuids_complete.uuid_cnt	= sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
	advdata.uuids_complete.p_uuids	= m_adv_uuids;

	memset(&options, 0, sizeof(options));
	options.ble_adv_whitelist_enabled		= false;
	options.ble_adv_directed_enabled		= true;
	options.ble_adv_directed_slow_enabled	= false;
	options.ble_adv_directed_slow_interval	= 0;
	options.ble_adv_directed_slow_timeout	= 0;
	options.ble_adv_fast_enabled			= true;
	options.ble_adv_fast_interval			= APP_ADV_FAST_INTERVAL;
	options.ble_adv_fast_timeout			= APP_ADV_FAST_TIMEOUT;
	options.ble_adv_slow_enabled			= false;
	options.ble_adv_slow_interval			= APP_ADV_SLOW_INTERVAL;
	options.ble_adv_slow_timeout			= APP_ADV_SLOW_TIMEOUT;

	err_code = ble_advertising_init(&advdata,
								NULL,
								&options,
								on_adv_evt,
								ble_advertising_error_handler);
	APP_ERROR_CHECK(err_code);
}

Thanks in advance.

[Alex]

It is expected behavior. Android remembers bonding information and automatically tries to connect to BLE device. Then BLE device accepts connection. If you want to stop that connection then either delete bonding information from Android or somehow reject any connection you don't want. As I mentioned Whitelist will reject unwanted connections.

[Borden]

Let me describe my dilemma in a more generic way, from a user's perspective.

Say I have two Android phone A&B, in the same place, then I realize there's no elegant way to add them both in my device's whitelist.

Once my device bonded with A,

1. if I disconnect from A, it will reconnect to A instantly, I have no chance to be discovered by B;
2. if I power up it with pm_peers_delete(), it will reconnect to A anyway, and since I want to add both A&B in my WL, deleting peer is not an option;
3. delete bond from A is a feasible way, but not elegant, they need to repair later;
4. turn off BT of A is currently my best choice, but still not so elegant, because A may have connected with other BT devices which I don't like to cut off.

And although I don't really understand why it's not possible to have my device connectable without a whitelist, I've still kept it, I merely don't advertise with it, because I haven't actually see the point of adv with WL in my scenario yet. If I do adv with WL, even if I turn the BT of A off, to let my device restart advertising, B still can't discover it cause B is not in it's WL. that's the reason why I set options.ble_adv_whitelist_enabled = false;