RE: Sending large extended adverts

Hung Bui — Fri, 21 Jul 2023 11:51:45 GMT

Hi Kyle,

You would need to us chained advertising.
Please take a look at my example here: RE: Advertising 1650 bytes of Host advertising data in an Auxiliary segment using Advertising Extensions

RE: Sending large extended adverts

saty9pd — Thu, 20 Jul 2023 13:11:26 GMT

kconfig flags:

CONFIG_BT_LL_SW_SPLIT=y

CONFIG_BT_EXT_ADV=y

CONFIG_BT_CTLR_ADV_EXT=y
CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=1650
CONFIG_BT_CTLR_ADV_DATA_CHAIN=y

example code:

#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/logging/log.h>

LOG_MODULE_REGISTER(reproduction, CONFIG_EDGE_LIVE_DATA_LOG_LEVEL);

static struct bt_le_ext_adv *adv;
static struct bt_data adv_data[7]; // 255 * 7 > 1650
static struct bt_le_adv_param adv_params;

//Fills adv_data array with bytes and returns how many entries used
static int fill_adv_data(const unsigned char *bytes, int len)
{
  __ASSERT(len <= 1650, "Too much data to fit in advertising packet");

  int ad_num = 0;
  while (len > 0) {
    adv_data[ad_num].type = BT_DATA_MANUFACTURER_DATA;
    adv_data[ad_num].data_len = MIN(len, 255);
    adv_data[ad_num].data = &bytes[ad_num*255];

    len -= 255;
    ad_num += 1;
  }
  return ad_num;
}

static int send_advert(const unsigned char *bytes, unsigned int len, unsigned char num_repetitions) {
  int ad_count = fill_adv_data(bytes, len);

  adv_params.interval_min = 1250;
  adv_params.interval_max = 1260;
  int err = bt_le_ext_adv_update_param(adv, &adv_params);
  if (err) {
    LOG_ERR("Failed to change advertising set params (%i)", err);
  }

  err = bt_le_ext_adv_set_data(adv, adv_data, ad_count, NULL, 0);
  if (err) {
    LOG_ERR("Failed to change advertising set data (%i)", err);
    return -1;
  } else {
    LOG_HEXDUMP_INF(bytes, len, "Advertising set data set to");
  }

  struct bt_le_ext_adv_start_param param = {
      .num_events = num_repetitions*10,
  };

  err = bt_le_ext_adv_start(adv, &param);
  if (err) {
    LOG_ERR("Failed to start advertising set (%i)", err);
    return -1;
  } else {
    LOG_INF("Advertising set started for %i repetitions, size %i bytes", num_repetitions, len);
  }

  return 0;
}

static uint8_t example_data[1000];

int example(void)
{
  adv_params.id = BT_ID_DEFAULT;
  adv_params.sid = 1;
  adv_params.secondary_max_skip = 0;
  adv_params.options = BT_LE_ADV_OPT_EXT_ADV | BT_LE_ADV_OPT_USE_IDENTITY;
  adv_params.interval_min = 1250;
  adv_params.interval_max = 1250 + 10;
  adv_params.peer = NULL;

  int err = bt_le_ext_adv_create(&adv_params, NULL, &adv);
  if (err) {
    LOG_ERR("Failed to create advertising set, err %d", err);
    return err;
  }

  return send_advert(example_data, 1000, 1);
}

Log output:

*** Booting Zephyr OS build v3.2.99-ncs2 ***

[00:00:00.454,833] <inf> bluetooth: Bluetooth initialized
[00:00:00.455,963] <err> bt_hci_core: opcode 0x2037 status 0x45
[00:00:00.455,963] <err> reproduction: Failed to change advertising set data (-5)