CCS/LAUNCHXL-CC26X2R1: RF Transmit Power Configuration

dogus yuksel

Tool/software: Code Composer Studio

Hi,

In simplePeripheral project, there is a "Default Tx Power" configuration under simple_peripheral.syscfg --> Radio: Configure BLE Radio Settings. The value of it is Zero normally but I need to extend the boards connection range and to do that I need to increase it I guess. Anyway, I set this config to 5 and then upload this to device but I cannot understand the tx power was set successfully or not.

How can I check that? (There is an app named NRF Connect. When I checked my board by using this app, I always see "tx pwr: 0" like below. Maybe this is not the correct way to check that I do not know)

over 5 years ago

0 YiKai Chen over 5 years ago

Guru 735685 points

To measure TX power precisely, we usually use Spectrum Analyzer to do conductive test.

0 dogus yuksel over 5 years ago in reply to YiKai Chen

Expert 1030 points

Hi,

Thank you for your answer but it is impossible for me right now to use SpectrumA. because we work remotely because of the virus. Is there any homemade test solution to measure the power like a texas tool or a third party ble application etc?

0 YiKai Chen over 5 years ago in reply to dogus yuksel

Guru 735685 points

If you fix the distance between your SmartPhone and test device, the RSSI reading should reflect the TX power change from 0 dbm to 5 dbm but you won't see exactly 5 dbm difference.

0 Eirik V over 5 years ago

TI__Guru 56590 points

The reported value is given in the payload of the advertisement or scan response and is not updated automatically (set by application programmer):

// Scan Response Data
static uint8_t scanRspData[] =
{
  // complete name
  17,   // length of this data
  GAP_ADTYPE_LOCAL_NAME_COMPLETE,
  'S',
  'i',
  'm',
  'p',
  'l',
  'e',
  'P',
  'e',
  'r',
  'i',
  'p',
  'h',
  'e',
  'r',
  'a',
  'l',

  // connection interval range
  5,   // length of this data
  GAP_ADTYPE_SLAVE_CONN_INTERVAL_RANGE,
  LO_UINT16(DEFAULT_DESIRED_MIN_CONN_INTERVAL),   // 100ms
  HI_UINT16(DEFAULT_DESIRED_MIN_CONN_INTERVAL),
  LO_UINT16(DEFAULT_DESIRED_MAX_CONN_INTERVAL),   // 1s
  HI_UINT16(DEFAULT_DESIRED_MAX_CONN_INTERVAL),

  // Tx power level
  2,   // length of this data
  GAP_ADTYPE_POWER_LEVEL,
  0       // 0dBm
};

You can set a fixed distance of a few meters and refer to the reported RSSI (-67 dBm in your screen shot). And then change the power level and verify of this is roughly reflected in the reported RSSI. Just be aware of the saturation limit (highest possible received and reported level) and other multipath propagation effects in addition to interference that might affect the result on the reported RSSI on your phone.

0 dogus yuksel over 5 years ago in reply to Eirik V

Expert 1030 points

Thank you so much

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CCS/LAUNCHXL-CC26X2R1: RF Transmit Power Configuration