Resolvable private address issues

Yes Summer, i beleive you are correct. BR JE_Dialog

Hi,
I am using SDK 5.0.3 software on DA14583DEVKT-B board.
I have taken the "ble_app_peripheral" (BLE example projects given).

I have changed "address_src" to "GAPM_GEN_STATIC_RND_ADDR".
I am facing issue while scanning for Bluetooth device. While scanning the Bluetooth device address is changing without any power cycle (of DA14583). As per Bluetooth core spec, if we have selected Static Random address then the Bluetooth address has to change on each power cycle.

My requirement is Bluetooth device address need to be changed on each power cycle.
Please guide me to resolve the issue.

Regards,
Mahesh Chandana.

Hi Mahesh,

This is a known issue, and there is a work around for this, you can use the GAPM_GEN_RAND_ADDR_CMD with a GAP_STATIC_ADDR type and store the generated address returned in GAPM_DEV_BDADDR_IND message. Then a GAPM_START_ADVERTISE_CMD should be sent with address source set to GAPM_PROVIDED_RND_ADDR and providing the stored random address in the address field, for more info regarding the commands please check the RW-BLE-GAP-IS. The idea is to call the above process during initialization of the device, for example when the setup of your database has been completed and then, after aquiring the bd_address you can start advertising.

Thanks MT_dialog

Hi,
In which function and in which file we need to do these sequence of changes.

"GAPM_PROVIDED_RND_ADDR" I have changed directly in "user_config.h".

Regards,
Mahesh Chandana.

Hi Mahesh,

There is no special file to implement this, just create a function that sends the command GAPM_GEN_RAND_ADDR_CMD, retrieve the command via the catch_rest mechanism (catch the GAPM_DEV_BDADDR_IND) and set the db address that you got from that indication when you are preparing the advertising command in the gapm_start_advertise_cmd struct in the op->addr member. Check the document mentioned above for any details regarding the structs.

Thanks MT_dialog

Hi

I am able to retrieve the catch_rest mechanism (catch the GAPM_DEV_BDADDR_IND) after sending the command "GAPM_GEN_RAND_ADDR_CMD". Able to read the Random address.

我打电话app_gapm_gen_rand_addr_msg_create() inside "default_app_on_db_init_complete() as shown in below

void default_app_on_db_init_complete( void )
{
struct gapm_gen_rand_addr_cmd* cmd;
cmd = app_gapm_gen_rand_addr_msg_create();
app_gapm_gen_rand_addr_msg_send(cmd);

EXECUTE_DEFAULT_OPERATION_VOID(default_operation_adv);
return;
}

After receiving the generated random bd address, where I need to update.
As you told we can update it in gapm_start_advertise_cmd struct in the op->addr member (as shown in below)

__INLINE struct gapm_start_advertise_cmd* app_advertise_start_msg_create(void)
{
struct gapm_start_advertise_cmd* cmd = KE_MSG_ALLOC(GAPM_START_ADVERTISE_CMD,
TASK_GAPM, TASK_APP,
gapm_start_advertise_cmd);

cmd->op->addr = RetrieveAddress;
return(cmd);
}

But we are receiving the random address in user level, same way we need to pass the random address from user level.
There is any provision to access the "op->addr " from the user level. Please guide me which is the suitable place to update the op->addr.

Regards,
Mahesh Chandana.

Hi Mahesh,

You can make a custom start advertising function without using the app_easy functions, allocate theGAPM_START_ADVERTISE_CMDmessage, fill it with the proper parameters and send it or, you can just change in the user_config.h the .address_src member to GAPM_PROVIDED_RND_ADDR and when start advertising invoke the app_easy_gap_undirected_advertise_get_active() then copy the generated address to the cmd->op.addr member and finally invoke the app_easy_gap_undirected_advertise_start().

Thanks MT_dialog

Hi sprhawk, Mahesh

正如我在前面的帖子已经表示你已经发布ed every message during the user_app_init() is discarded since the stack gets reseted after the invokation of the function. In the post #6 "The idea is to call the above process during initialization of the device, for example when the setup of your database has been completed and then, after aquiring the bd_address you can start advertising." So you can generate the bd_address after your database gets initialized (send the command in the app_on_db_init_complete) or if dont have any database when the device configuration is complete (send the generate address command when app_on_set_dev_config_complete()). After you have aquired the bd_address (meaning in the handler that handler the GAPM_DEV_BDADDR_IND) you can copy the address in a variable and allocate your advertising command fill in the proper structures and send the message (as Mahesh suggested). Or you can wait for the GAPM_CMP_EVT (that indicates that the command has completed) and start advertising from that callback. This will ensure that the sequence of messages will be proper.

Also check this posthttp://support.dialog-semiconductor.com/question-about-generation-static...

Thanks MT_dialog