iOS + nRF51822 = iBeacon?

Question

I have a few nRF51822 sensors lying around and I would like to start playing with iOS iBeacon setup. The issues that I'm running into is in order to do

- (id)initWithProximityUUID:(NSUUID *)proximityUUID identifier:(NSString *)identifier;

you need to know the sensors proximityUUID. Looking at the CLBeacon docs it seems this is a read only attribute of the sensor, but how / where do I read this from the

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI

and I'm seeing kCBAdvDataServiceUUID with a single string of 2500, but I don't think that's it. Anyone have any direction or insight?

Thanks

Answer 1

The devices you build with the nRF51822 sensors will advertise the proximityUUID via the iBeacon protocol which, to my understanding, has not been published yet. Until then, the easiest way to have a play is with another iOS device that advertises its presence. The UUID itself is something that you define.

This article gives a pretty good overview of what you need to do.

Answer 2

You may also have use in looking at this code snippet, first shared on Nordic's own Q&A site:

typedef __packed struct
{
    uint16_t unknown1;
    uint8_t uuid[16];
    uint16_t major;
    uint16_t minor;
    uint8_t unknown2;
} clbeacon_info_t;
...
static void advertising_init(void)
{
    uint32_t      err_code;
    uint8_t       flags = BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED;
    ble_advdata_t advdata;

    uint8_t uuid[16] = {0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0};

    clbeacon_info_t beacon_info;
    beacon_info.unknown1 = 0x1502;
    memcpy(&beacon_info.uuid, &uuid, sizeof(uuid));
    beacon_info.major = 0x3412;
    beacon_info.minor = 0x7798;
    beacon_info.unknown2 = 0xC5;

    ble_advdata_manuf_data_t manuf_specific_data;
    manuf_specific_data.company_identifier = 0x004C;
    manuf_specific_data.data.p_data        = (uint8_t *) &beacon_info;
    manuf_specific_data.data.size          = sizeof(beacon_info);

    // Build and set advertising data
    memset(&advdata, 0, sizeof(advdata));

    advdata.name_type               = BLE_ADVDATA_NO_NAME;
    advdata.flags.size              = sizeof(flags);
    advdata.flags.p_data            = &flags;
    advdata.p_manuf_specific_data   = &manuf_specific_data;

    err_code = ble_advdata_set(&advdata, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Start advertising.
 */
static void advertising_start(void)
{
    uint32_t             err_code;
    ble_gap_adv_params_t adv_params;

    // Start advertising
    memset(&adv_params, 0, sizeof(adv_params));

    adv_params.type        = BLE_GAP_ADV_TYPE_ADV_NONCONN_IND;
    adv_params.p_peer_addr = NULL;
    adv_params.fp          = BLE_GAP_ADV_FP_ANY;
    adv_params.interval    = APP_ADV_INTERVAL;
    adv_params.timeout     = APP_ADV_TIMEOUT_IN_SECONDS;

    err_code = sd_ble_gap_adv_start(&adv_params);
    APP_ERROR_CHECK(err_code);
    nrf_gpio_pin_set(ADVERTISING_LED_PIN_NO);
}

...

Answer 3

The UUID has to be set in the Advertisement Data of the BLE Device Here is a blog post describing the reverse engineering of the Advertising Package. With this format you can make a firmware for your BLE sensors that is recognized as an iBeacon by iOS.

Once you have a working Beacon Hardware of which you know the UUID you can look for it with - (void)startMonitoringForRegion:(CLRegion *)region of the CLLocationManager