.. _faq_ble_tx_power:

How to adjust BLE Tx power
##########################

Applications can control BLE Advertisement Tx power and BLE Connection Transmit power by making Atmosic API calls as described below.

1. BLE Advertisement power setting
==================================

For ATM34xx platform
--------------------

The default Adv TX Power is 0 dBm. This can be altered by an application by making an API call to ``atm_vendor_set_adv_tx_power()``.

For example, to set advertisement power to 4 dBm:

.. code-block:: c

   atm_vendor_set_adv_tx_power(TX_POWER_4_DBM);

For ATM33xx platform
--------------------

The Adv Tx power uses ``CONFIG_MAX_TX_PWR`` setting for Advertisements. An application can alter the Advertisement power by setting ``CONFIG_MAX_TX_PWR`` to a different value in its prj.conf file.

For example, to set Advertisement power to 8 dBm, set it as follows in the prj.conf file:

.. code-block:: kconfig

   CONFIG_MAX_TX_PWR=8

2. BLE Connection Tx Power setting (ATM33xx, ATM34xx)
======================================================

The default Connection Tx Power is 0 dBm. Applications can modify the Connection Tx Power by making an Atmosic provided API call.

For example, to set Connection Tx Power to 8 dBm, here is a code snippet that is typically inserted in the connected callback handler:

.. code-block:: c

   #include "atm_vendor_api.h"

   int err = atm_vendor_set_con_tx_power(conn_hdl, TX_POWER_8_DBM);
   if (err) {
           LOG_ERR("Failed to set connection TX power level %d", TX_POWER_8_DBM);
   } else {
           LOG_INF("Successfully set connection TX power level %d", TX_POWER_8_DBM);
   }

In Application's prj.conf file, include these settings:

.. code-block:: kconfig

   CONFIG_ATM_VENDOR_API=y
   CONFIG_VND_API_SET_ADV_TX_POWER=y
   CONFIG_VND_API_SET_CON_TX_POWER=y

Look at ``lib/atm_vendor/api_include/atm_vendor_api.h`` for various supported Power Levels in the system.