How to set the transmit power when using nRF52833 for broadcasting on nRF Connect SDK ?

[Kenny]

I am using nRF52833 on ncs to turn on the extended broadcast. After referring to the corresponding settings, I found that the transmit power setting does not take effect. Is the setting wrong? Or need other methods to set the transmit power？

The version I use is ncs v1.6.0

Below is part of my code：

in main.c：

#include <zephyr.h>
#include <zephyr/types.h>
#include <stddef.h>
#include <sys/util.h>

#include <bluetooth/hci.h>
#include <bluetooth/hci_vs.h>
#include <bluetooth/conn.h>
#include <bluetooth/uuid.h>
#include <bluetooth/gatt.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/controller.h>

#include <sys/byteorder.h>
#include <bluetooth/hci_vs.h>

#include <logging/log.h>
LOG_MODULE_REGISTER(mt_adv, 3);

static struct bt_le_ext_adv *adv_set;

static const struct bt_data ad[] = {
	BT_DATA_BYTES(BT_DATA_FLAGS, BT_DATA_UUID128_SOME),
	BT_DATA_BYTES(BT_DATA_MANUFACTURER_DATA,
		      	0x4C, 0x00, 			/* Apple. */
		      	0x02, 0x15, 			/* iBeacon. */
		      	0x01, 0x12, 0x23, 0x34,	/* UUID-1. */
				0x45, 0x56, 0x67, 0x78,	/* UUID-2. */
				0x89, 0x9A, 0xAB, 0xBC,	/* UUID-3. */
				0xCD, 0xDE, 0xEF, 0xF0,	/* UUID-4. */
		      	0x66,0x66, 				/* Major. */
		      	0x66,0x66, 				/* Minor. */
		      	0xC5),					/* Calibrated RSSI @ 1m. */
    BT_DATA(BT_DATA_NAME_COMPLETE, CONFIG_BT_DEVICE_NAME, (sizeof(CONFIG_BT_DEVICE_NAME) - 1))
};

const static struct bt_le_adv_param param =
		BT_LE_ADV_PARAM_INIT(
                     BT_LE_ADV_OPT_EXT_ADV | BT_LE_ADV_OPT_CODED | BT_LE_ADV_OPT_CONNECTABLE,
				     BT_GAP_ADV_FAST_INT_MIN_2,
				     BT_GAP_ADV_FAST_INT_MIN_2,
				     NULL);

void get_tx_power(uint8_t handle_type, uint16_t handle, int8_t *tx_pwr_lvl)
{
	struct bt_hci_cp_vs_read_tx_power_level *cp;
	struct bt_hci_rp_vs_read_tx_power_level *rp;
	struct net_buf *buf, *rsp = NULL;
	int err;

	*tx_pwr_lvl = 0xFF;
	buf = bt_hci_cmd_create(BT_HCI_OP_VS_READ_TX_POWER_LEVEL,
				sizeof(*cp));
	if (!buf) {
		LOG_ERR("Unable to allocate command buffer\n");
		return;
	}

	cp = net_buf_add(buf, sizeof(*cp));
	cp->handle = sys_cpu_to_le16(handle);
	cp->handle_type = handle_type;

	err = bt_hci_cmd_send_sync(BT_HCI_OP_VS_READ_TX_POWER_LEVEL,
				   buf, &rsp);
	if (err) {
		uint8_t reason = rsp ?
			((struct bt_hci_rp_vs_read_tx_power_level *)
			  rsp->data)->status : 0;
		LOG_ERR("Read Tx power err: %d reason 0x%02x\n", err, reason);
		return;
	}

	rp = (void *)rsp->data;
	*tx_pwr_lvl = rp->tx_power_level;

	net_buf_unref(rsp);
}

void set_tx_power(uint8_t handle_type, uint16_t handle, int8_t tx_pwr_lvl)
{
    struct bt_hci_cp_vs_write_tx_power_level *cp;
    struct bt_hci_rp_vs_write_tx_power_level *rp;
    struct net_buf *                          buf, *rsp = NULL;
    int                                       err;

    buf = bt_hci_cmd_create(BT_HCI_OP_VS_WRITE_TX_POWER_LEVEL, sizeof(*cp));
    if (!buf) {
        LOG_INF("Unable to allocate command buffer\n");
        return;
    }

    cp                 = net_buf_add(buf, sizeof(*cp));
    cp->handle         = sys_cpu_to_le16(handle);
    cp->handle_type    = handle_type;
    cp->tx_power_level = tx_pwr_lvl;

    err = bt_hci_cmd_send_sync(BT_HCI_OP_VS_WRITE_TX_POWER_LEVEL, buf, &rsp);
    if (err) {
        uint8_t reason = rsp ? ((struct bt_hci_rp_vs_write_tx_power_level *)rsp->data)->status : 0;
        LOG_INF("Set Tx power err: %d reason 0x%02x\n", err, reason);
        return;
    }

    rp = (void *)rsp->data;
    LOG_INF("Actual Tx Power: %d\n", rp->selected_tx_power);

    net_buf_unref(rsp);
}

void main(void)
{
    int err = bt_enable(NULL);
    if (err) {
        LOG_ERR("[%04d] Bluetooth init failed (err %d).\n", __LINE__, err);
        return;
    }
    LOG_INF("[%04d] Bluetooth initialized.", __LINE__);

    int tx_power = 0;
    set_tx_power(BT_HCI_VS_LL_HANDLE_TYPE_ADV, 0, tx_power);

    err = bt_le_ext_adv_create(&param, NULL, &adv_set);
    if (err) {
        LOG_ERR("[%04d] Create extended advertising set_id failed (err %d).\n", __LINE__, err);
        return;
    }

    err = bt_le_ext_adv_set_data(adv_set, ad, ARRAY_SIZE(ad), NULL, 0);
    if (err) {
        LOG_ERR("[%04d] Failed to set advertising data (%d).\n", __LINE__, err);
        return;
    }

    err = bt_le_ext_adv_start(adv_set, NULL);
    if (err) {
        LOG_ERR("[%04d] Extended advertising failed to start (err %d).\n", __LINE__, err);
        return;
    }
    LOG_INF("[%04d] Extended advertising enable...", __LINE__);
}

in prj.conf:

# Bluetooth.
CONFIG_BT=y
CONFIG_BT_DEBUG_LOG=n
CONFIG_BT_BROADCASTER=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME="NCS-adv"

CONFIG_BT_LL_SW_SPLIT=y
CONFIG_BT_LL_SOFTDEVICE=n
CONFIG_BT_CTLR=y
CONFIG_BT_CTLR_CONN_RSSI=y
CONFIG_BT_CTLR_ADVANCED_FEATURES=y
CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y

CONFIG_BT_EXT_ADV=y
CONFIG_BT_PER_ADV=y
CONFIG_BT_CTLR_ADV_EXT=y
CONFIG_BT_CTLR_PHY_CODED=y

[Kenny]

When the other settings are not changed and the broadcast with extended broadcast is changed to ordinary broadcast, the setting of transmit power can take effect... Why?