esp_ble_tx_power_set has no effect

[tbitowt]

Hi,

I'm making an application which uses Ble Scan for finding local devices. Unfortunately, range of Ble Scan seems to be very bad. I have tried to set up tx power via esp_ble_tx_power_set function, but seems that it does not have any impact on scan results.

In fact, my scan does not find any device behind the wall. Maybe it's normal, but I heard that it should be working fine.

I have compared results of average rssi values with ESP_BLE_PWR_TYPE_SCAN power set to N12 and P9 (30s scan results).

• For N12 results are:
  Min: -88, Max: -72, Avg: -80.909091
• For P9 results are:
  Min: -92, Max: -72, Avg: -80.878109

As some code background, I have executed esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_SCAN, ESP_PWR_LVL_P9); function right after esp_bluedroid_enable(). I have tried also setting all of the rest PWR_TYPE powers to same values (with also no effect).

I'm using NodeMCU-32S board.

Is it possible to extend BLE scan range somehow?

[WiFive]

Changing TX power on esp32 will only change RSSI on the receiving device.

[tbitowt]

Does it mean that there's no option to make BLE range for scanning wider?