Connecting to only one central. How to? detailed

RE: Connecting to only one central. How to? detailed

Hung Bui — Wed, 13 Jul 2016 08:24:32 GMT

@Antonio: thanks for the nice words. I'm happy to help :) If I answered your question please mark the answer as accepted (the checked button)

RE: Connecting to only one central. How to? detailed

Antonio — Wed, 13 Jul 2016 07:47:28 GMT

@HungBui: well, it's ok, thanks a lot for answer all my question, it was very usefull, i know some of them was repetitive. Congratulations to the nordic support team, your job is well done in this forum,

RE: Connecting to only one central. How to? detailed

Hung Bui — Tue, 12 Jul 2016 10:34:01 GMT

@Antonio: Yes you can use NUS. If you have new question that's not related to the original question, please create a new case.

RE: Connecting to only one central. How to? detailed

Antonio — Mon, 11 Jul 2016 15:18:27 GMT

ok i got it.. what do you recommend to send data once a connection has established?

For e.g: i need to send some bytes trough BLE once the devices are connect. NUS service??

RE: Connecting to only one central. How to? detailed

Hung Bui — Mon, 11 Jul 2016 13:42:48 GMT

@Antonio: No, you don't have to pay if you use BLE_GAP_ADDR_TYPE_RANDOM_STATIC, but according to the spec, the address should be generated randomly. You can use any tool to generate the random number, for example this.

RE: Connecting to only one central. How to? detailed

Antonio — Mon, 11 Jul 2016 12:57:08 GMT

okok.. look what i have done..

Central: i set my own address to the device but as "random static address" .

ble_gap_addr_t addr ={BLE_GAP_ADDR_TYPE_RANDOM_STATIC,{0xAD,0x16,0xBC,0xCA,0x30,0xE9}} ;
err_code = sd_ble_gap_address_set(BLE_GAP_ADDR_CYCLE_MODE_NONE, &addr);
APP_ERROR_CHECK(err_code);

Peripheral: i advertise with whitelist, and add an specific address to my whitelist.

ble_gap_addr_t   * p_whitelist_addr[1];
ble_gap_addr_t        whitelist_addr={BLE_GAP_ADDR_TYPE_RANDOM_STATIC,{0xAD,0x16,0xBC,0xCA,0x30,0xE9}} ;
whitelist.pp_addrs   =  p_whitelist_addr;

with this, the system works as i want to.. now, you mentioned "generated randomly", if i use an address's type: BLE_GAP_ADDR_TYPE_RANDOM_STATIC, and i set my own address, do i have to pay for that ?? i'm talking about production mode..

RE: Connecting to only one central. How to? detailed

Hung Bui — Mon, 11 Jul 2016 12:15:35 GMT

@Antonio: No, the DFU is just an example, you don't have to increase address.

If you use random static address, you don't need to register and pay for your public address. You just need to generate it randomly, not 01:02:03:04:05:06 :) .

RE: Connecting to only one central. How to? detailed

Antonio — Mon, 11 Jul 2016 09:35:54 GMT

@Hungbui: you mean that, when we will want to sell this product, we must pay for a own public address??

I don`t want to implement DFU yet, so i don't need to increase the address by one, do i?

RE: Connecting to only one central. How to? detailed

Hung Bui — Mon, 11 Jul 2016 07:18:39 GMT

@Antonio: You can set the address to anything you want, for testing purpose. For production, you should avoid using the public addresses domain that already claimed by other companies. Regarding the reason we change the address in the DFU example, please have a look at question D here.

RE: Connecting to only one central. How to? detailed

Antonio — Fri, 08 Jul 2016 15:06:57 GMT

ok i found it..

this is the code..

ble_gap_addr_t addr;

        err_code = sd_ble_gap_address_get(&addr);
        APP_ERROR_CHECK(err_code);

        // Increase the BLE address by one when advertising openly.
        addr.addr[0] += 1;

        err_code = sd_ble_gap_address_set(BLE_GAP_ADDR_CYCLE_MODE_NONE, &addr);
        APP_ERROR_CHECK(err_code);

instead of get the actual address with sd_ble_gap_address_get(&addr), i want to set my own address for example: {01:02:03:04:05:06} is it possible? and how?

and why they increase the address by one?

RE: Connecting to only one central. How to? detailed

Hung Bui — Fri, 08 Jul 2016 14:00:29 GMT

@Antonio: Please call sd_ble_gap_address_set() to write the address. You can call this at any time after you enable the softdevice. To read the current address, you call sd_ble_gap_address_get(). Please have a look at function dfu_transport_update_start() in dfu_transport_ble.c file in the SDK \components\libraries\bootloader_dfu to see an example of using them.

RE: Connecting to only one central. How to? detailed

Antonio — Fri, 08 Jul 2016 13:38:39 GMT

i'm working with nrf52832

but i want to set my own device address??how i can do it?

RE: Connecting to only one central. How to? detailed

Hung Bui — Fri, 08 Jul 2016 11:52:34 GMT

@Antonio: Which central device are you using ? Nordic nRF5 chip by default don't change address.

RE: Connecting to only one central. How to? detailed

Antonio — Thu, 07 Jul 2016 14:18:05 GMT

@hungbui: finally i found it, the problem was the endiannes... i found to connect my peripheral with one specific central...

Now, i think my central device is running with a random address because it change sometime... you told me that i can set a static address in my central with sd_ble_gap_address_set() but, where i have to do that?? in the advetising_init()???

RE: Connecting to only one central. How to? detailed

Hung Bui — Thu, 07 Jul 2016 13:31:44 GMT

@Antonio: if you want to add more detail about your question, please edit the question. Don't add it as an answer. It could be the endianess was wrong, you could try to set the direct address /or whitelist in the advertiser to

{0x48,0xAD,0x68,0x89,0xA5,0x80};

You can try to capture a sniffer trace, we can see what is in the advertising packet.

RE: Connecting to only one central. How to? detailed

Antonio — Thu, 07 Jul 2016 10:54:57 GMT

@HungBui: i think i had my code ready, but when the central tries to connect, it gets disconnect..

This is my central device address:

this is my function start_advertising() in main.c

/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    uint32_t             err_code;
ble_gap_adv_params_t adv_params;
ble_gap_whitelist_t  whitelist;
ble_gap_addr_t   * p_whitelist_addr[1];
ble_gap_addr_t        whitelist_addr={BLE_GAP_ADDR_TYPE_RANDOM_STATIC,{0x80,0xA5,0x89,0x68,0xAD,0x48}} ;
uint8_t addr[6] = {0x80,0xA5,0x89,0x68,0xAD,0x48};  
uint8_t adv_data[15] = {0x07,0x09,0x4E,0x6F,0x72,0x64,0x69,0x63,0x02,0x01,0x04,0x03,0x03,0x0F,0x18};
uint8_t adv_data_length = 15;

//Setting up the advertising data with scan response data = Null
err_code = sd_ble_gap_adv_data_set(adv_data, adv_data_length, NULL, NULL);    

//Configure the advertising parameter and whitelist
memset(&adv_params, 0, sizeof(adv_params));
adv_params.type        = BLE_GAP_ADV_TYPE_ADV_IND;
adv_params.p_peer_addr = NULL;
adv_params.interval    = 64;
adv_params.timeout     = 180;
p_whitelist_addr[0] = &whitelist_addr;
whitelist.addr_count = 1;
whitelist.pp_addrs   =  p_whitelist_addr;
whitelist.pp_irks = NULL;
whitelist.irk_count =0;
adv_params.fp          = BLE_GAP_ADV_FP_FILTER_CONNREQ;
adv_params.p_whitelist = &whitelist;
err_code = sd_ble_gap_adv_start(&adv_params);
}

and this is my main.c

/**@brief Function for application main entry.
 */
int main(void)
{
	  uint32_t err_code;
	  bool erase_bonds;
		configurar_puerto();
	
//	 leds_init();
//    timers_init();
	
	  // inicializo el timer para mostrar el blinking del advertoising
	  APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);
    err_code = bsp_init(BSP_INIT_LED, APP_TIMER_TICKS(100, APP_TIMER_PRESCALER), NULL);
    APP_ERROR_CHECK(err_code);
	
	  
    buttons_init();
//	  nrf_delay_ms(50);
		ble_stack_init();
	
    device_manager_init(erase_bonds);
	  gap_params_init();
    services_init();
    advertising_init();
	  conn_params_init();
	
	// Empiezo el advertizing
//	  err_code = ble_advertising_start(BLE_ADV_MODE_FAST);
//    APP_ERROR_CHECK(err_code);
    advertising_start();
	
	// Espero un evento
    for (;;)
    {
        power_manage();
    }

}

What it could happening?

RE: Connecting to only one central. How to? detailed

Hung Bui — Wed, 06 Jul 2016 14:12:51 GMT

@Antonio: it's the DEVICE_MANAGER_MAX_BONDS you need to modify to 1.

Also make sure you always advertise with whitelist (BLE_FAST_ADV_WHITELIST) after you have the address /IRK. I suggest you to get familiar to our example in the SDK, for example the proximity example, where whitelist is used.

RE: Connecting to only one central. How to? detailed

Antonio — Tue, 05 Jul 2016 12:58:02 GMT

Another question... i was reading about peer and device manager. Peer manager is on experimental, so i will use device manager.

you write above that i can use whitelist, i limit the number of peer devices that i want to store on my whitelist, this way if i limit to only 1, the unique device that could connect to my peripheral will be the first one.. How i can set the maximun number of peer device?where?

RE: Connecting to only one central. How to? detailed

Antonio — Tue, 05 Jul 2016 11:36:45 GMT

what i am doing... in the central i am looking the specific uuid service with is_uiid_present() and it is ok, the central only connect with specific peripheral. In the peripheral i am advertising with the specific peer address, but how i change the the device address in the central in order to match with my advertising??? you said sd_ble_gap_address_set() but where? in main???

but now

RE: Connecting to only one central. How to? detailed

Antonio — Tue, 05 Jul 2016 11:33:36 GMT

but sd_ble_gap_address_set() in main???

RE: Connecting to only one central. How to? detailed

Hung Bui — Tue, 05 Jul 2016 10:12:30 GMT

@Antonio: In the sniffer, if you click on a Connect request packet, you can find the address of the init device (Init address).

To change the address of a nRF52 central, you can call sd_ble_gap_address_set().

RE: Connecting to only one central. How to? detailed

Antonio — Tue, 05 Jul 2016 09:23:39 GMT

I'm using a nRF52 DK as central, and another nRF52 DK as peripheral.. but with sniffer i just only get the address of my peripheral not my central::

RE: Connecting to only one central. How to? detailed

Hung Bui — Tue, 05 Jul 2016 08:54:49 GMT

@Antonio: You need to find your own central device address. You can use a sniffer for this. Which central are you testing with ?

RE: Connecting to only one central. How to? detailed

Antonio — Tue, 05 Jul 2016 08:15:00 GMT

ok, Hung Bui , i saw your //ADDED lines in the code.. with this you set to only advertise to that especific peer address, now, how you do that but in the central device? i mean, how you set

----> {ba:2d:f2:f5:ed:5c} as central's peer address

RE: Connecting to only one central. How to? detailed

Hung Bui — Mon, 04 Jul 2016 14:30:08 GMT

@Antonio: I just updated my answer with an example. Please make sure you add the correct address for your central. Otherwise you won't be able to see anything when you scan. Not only the address (make sure the Endianness is correct) but also the address type must match.

Please look for "//ADDED" comment where the modifications are added. There are 2 place in main.c