nRF52 . BLE . Tx Power 설정.

 

 

 

BLE Advertising 상태의 Tx Power 설정. 

-  함수 sd_ble_gap_tx_power_set ( , , ) 호출하면서 마지막 인자로 설정하려는 출력 파워 기록한다. 

- advertising init 과정에서 함수 ble_advertising_init 호출 이후 advertising  핸들 정상 확보된 이후에만  sd_ble_gap_tx_power_set( ) 호출가능하다. 

- 아래 호출 예는 ble_advertising_init 호출 직후 즉시 tx power 설정 하는 예제.  

static void advertising_init()
{

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);
    
    
    //BLE TX Power set for Advertising. after ble_advertising_init(&m_advertising,)
    sd_ble_gap_tx_power_set(
      BLE_GAP_TX_POWER_ROLE_ADV // uint8_t role
      , m_advertising.adv_handle //uint16_t handle
      , 0 // int8_t tx_power. nRF52840.-20~+8 4dB step.  -20,-16,-12,-8,-4,0,4,,8
    );

}

 

BLE Connection 상태의 Tx Power 설정. 

- 별도로 설정하지 않은 경우는  앞의 advertising 상태에서 설정한 동일 출력 파워 적용됨. 

- ble connection handle (sdk 예제코드에서 변수 m_conn_handle 로 되어있음.)정상 확보 상태에서만 sd_ble_gap_tx_power_set ( , , )  호출가능하다. 

 

    //BLE TX Power set for ble connection state. 
    sd_ble_gap_tx_power_set(
      BLE_GAP_TX_POWER_ROLE_CONN // uint8_t role
      , m_conn_handle //uint16_t handle
      , 0 // int8_t tx_power. nRF52840.-20~+8 4dB step.  -20,-16,-12,-8,-4,0,4,,8
    );

 

 

BLE Central 인 경우 Tx Power 설정. 

- sd_ble_gap_tx_power_set ( , , ) 1번 인자는 BLE_GAP_TX_POWER_ROLE_SCAN_INIT 로 한다. 이 경우 2번 인자 handle 은 함수 내부적으로 참조되지 않음. 

- 아무 시점에나 호출해도 됨.  

    //BLE TX Power set for Central
    
    sd_ble_gap_tx_power_set(
      BLE_GAP_TX_POWER_ROLE_SCAN_INIT // uint8_t role
      , 0 // uint16_t handle
      , 0 // int8_t tx_power. nRF52840.-20~+8 4dB step.  -20,-16,-12,-8,-4,0,4,,8
    );

 

 

 

 

 

 

BLE . RF 출력파워 설정 함수 

 

uint32_t sd_ble_gap_tx_power_set	(	uint8_t 	role,
uint16_t 	handle,
int8_t 	tx_power 
)

 

Set the radio's transmit power.Parameters

[in]	role	The role to set the transmit power for, see BLE_GAP_TX_POWER_ROLES for possible roles.
[in]	handle	The handle parameter is interpreted depending on role: If role is BLE_GAP_TX_POWER_ROLE_CONN, this value is the specific connection handle. If role is BLE_GAP_TX_POWER_ROLE_ADV, the advertising set identified with the advertising handle, will use the specified transmit power, and include it in the advertising packet headers if ble_gap_adv_properties_t::include_tx_power set. For all other roles handle is ignored.
[in]	tx_power	Radio transmit power in dBm (see note for accepted values).

NoteSupported tx_power values: -40dBm, -20dBm, -16dBm, -12dBm, -8dBm, -4dBm, 0dBm, +3dBm and +4dBm. In addition, on some chips following values are supported: +2dBm, +5dBm, +6dBm, +7dBm and +8dBm. Setting these values on a chip that does not support them will result in undefined behaviour.The initiator will have the same transmit power as the scanner.When a connection is created it will inherit the transmit power from the initiator or advertiser leading to the connection.Return values

NRF_SUCCESS	Successfully changed the transmit power.
NRF_ERROR_INVALID_PARAM	Invalid parameter(s) supplied.
BLE_ERROR_INVALID_ADV_HANDLE	Advertising handle not found.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid connection handle supplied.

 

from : sd_ble_gap_tx_power_set - S140 SoftDevice version 7.3.0

 

 

 

 

연관 

 

nRF52 . BLE . RSSI

 

상위정리

STM32. nRF52. ESP32. EFM8. EFM32. PSoC 활용 정리.

 

 

 

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첫 등록 : 2019.01.23 

최종 수정 : 2023.01.29

단축 주소 : https://igotit.tistory.com/4205

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