Send TX Power in Advertising Packet

[Justin]

I want to send Tx power in advertisement packet.

Currently I am using following code.

 int8_t txpower_level;  

static ble_advertising_init_t init =

{

    .advdata.p_manuf_specific_data = &manufacturing_data,

    .advdata.name_type = BLE_ADVDATA_FULL_NAME,

    .advdata.include_appearance = 0,

    .advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE,

    .advdata.p_tx_power_level = &tx_power_level,

    .srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]),

    .srdata.uuids_complete.p_uuids = m_adv_uuids,

    .config.ble_adv_fast_enabled = 1,

    .config.ble_adv_fast_interval = 4 * 1600,

    .config.ble_adv_fast_timeout = 0,

    .evt_handler = on_adv_evt,

};

    ble_advertising_init(&m_advertising, &init);

    ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);

    tx_power_level = -4;

    sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_advertising.adv_handle, tx_power_level );

Is this the right way to send transmit power? or should I call  sd_ble_gap_tx_power_set before and then ble_advertising_init() followed by ble_advertising_start()?

[Kenneth]

Hi,

There is not direct dependency between when you set .advdata.p_tx_power_level and call sd_ble_gap_tx_power_set(). It is in theory possible to dynamically change the output power at any time by calling sd_ble_gap_tx_power_set(). However it make sense to call it before you start advertisement.

Best regards,
Kenneth

[Justin]

Hi Kenneth,

Thanks for your reply.

Kenneth said:

However it make sense to call it before you start advertisement.

Is there a way by which I can update the advt. packet to transmit the power level without starting and stopping the advertisement?

I mean in my application, I change the transmit power as needed but everytime  restarting the advertisement is not feasible.

How can I update .advdata.p_tx_power_level to show the change in power in advt. packet?

[Kenneth]

Check out this thread, which I think discuss the same:

https://devzone.nordicsemi.com/f/nordic-q-a/55296/how-to-update-advertised-tx-power