一、背景
1.1 发射功率范围
(最大)5dB、4dB、3dB、2dB、1dB、（默认）0dB、-3dB、-6dB、-9dB、-12dB、-15dB、-18dB、（最小）-21dB
#define HCI_EXT_TX_POWER_MINUS_21_DBM LL_EXT_TX_POWER_MINUS_21_DBM //!< -21 dBm
#define HCI_EXT_TX_POWER_MINUS_18_DBM LL_EXT_TX_POWER_MINUS_18_DBM //!< -18 dBm
#define HCI_EXT_TX_POWER_MINUS_15_DBM LL_EXT_TX_POWER_MINUS_15_DBM //!< -15 dBm
#define HCI_EXT_TX_POWER_MINUS_12_DBM LL_EXT_TX_POWER_MINUS_12_DBM //!< -12 dBm
#define HCI_EXT_TX_POWER_MINUS_9_DBM LL_EXT_TX_POWER_MINUS_9_DBM //!< 9 dBm
#define HCI_EXT_TX_POWER_MINUS_6_DBM LL_EXT_TX_POWER_MINUS_6_DBM //!< 6 dBm
#define HCI_EXT_TX_POWER_MINUS_3_DBM LL_EXT_TX_POWER_MINUS_3_DBM //!< 3 dBm
#define HCI_EXT_TX_POWER_0_DBM LL_EXT_TX_POWER_0_DBM //!< 0 dBm
#define HCI_EXT_TX_POWER_1_DBM LL_EXT_TX_POWER_1_DBM //!< 1 dBm
#define HCI_EXT_TX_POWER_2_DBM LL_EXT_TX_POWER_2_DBM //!< 2 dBm
#define HCI_EXT_TX_POWER_3_DBM LL_EXT_TX_POWER_3_DBM //!< 3 dBm
#define HCI_EXT_TX_POWER_4_DBM LL_EXT_TX_POWER_4_DBM //!< 4 dBm
#define HCI_EXT_TX_POWER_5_DBM LL_EXT_TX_POWER_5_DBM //!< 5 dBm
1.2 发射功率作用
发射功率越大，信号越强，距离越远，功耗越大。
发射功率越小，信号越弱，距离越近，功耗越小。
发射功率只是影响通信距离的因素之一，通信距离还与环境、天线选型、天线电路匹配等因素有关。
二、使用方法
以SDK2.4 multi_role工程为例，在multi_role.c中需要调整发射功率的地方加入以下其中一条
//设置发射功率（默认-47dB~-51dB）
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_21_DBM); //-71dB~-76dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_18_DBM); //-65dB~-72dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_15_DBM); //-62dB~-67dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_12_DBM); //-60dB~-63dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_9_DBM); //-57dB~-61dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_6_DBM); //-54dB~-59dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_MINUS_3_DBM); //-50dB~-53dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_0_DBM); //-46dB~-50dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_1_DBM); //-45dB~-50dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_2_DBM); //-43dB~-47dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_3_DBM); //-42dB~-47dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_4_DBM); //-41dB~-45dB
//HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_5_DBM); //-41dB~-44dB
• 由 Leung 写于 2019 年 3 月 30 日
