SDK: 7.10

Reproducibility: 100%

The HCI_EXT_SetTxPowerDbmCmd() seems to not change the txPower of the device.

A basic_ble project was used to reproduce this behavior.  A call to the HCI_EXT_SetTxPowerDbmCmd() function was added before the BLEAppUtil_initAdvSet() funciton call inside the Peripheral_start() function located in the app_peripheral.c file as shown below:

status = BLEAppUtil_registerEventHandler(&peripheralAdvHandler);
if(status != SUCCESS)
{
    return(status);
}

// ADDITION START
// 8dbm
{
    const int8_t txPower = 8;
    const uint8_t fraction = 0;
    HCI_EXT_SetTxPowerDbmCmd(txPower, fraction);
}    
// ADDITION END
status = BLEAppUtil_initAdvSet(&peripheralAdvHandle_1, &advSetInitParamsSet_1);
if(status != SUCCESS)
{
    // Return status value
    return(status);
} 

The value of the txPower variable was changed between -20dbm, 0dbm, and 8dbm. Regardless of the value used, there was no measurable difference in txPower. An RSSI measurement was conducted using a smart phone as a scanner and a current test was made using EnergyTrace (with display disabled, LED jumpers removed, and only 3.3V and GND pins connected between the LP-EM-CC2340R5 and the LP-XDS110ET) The results of these tests is shown below:

 
These measurements show that there is no significant difference between the txPower settings.