Esp32-snippets: BLE server tx power

[menesesleonardo]

Hello, I'm following this example of a BLE server

https://github.com/nkolban/ESP32_BLE_Arduino/tree/master/examples/BLE_server

however, the default tx power of this server is -21dBm.

I've seen that this value is standardized to -21(ultra low power) -15(low power), -7 and -4 (medium) and 0,1 and 4 (high power). Is it possible to adjust this value?

[chegewara]

I think this is question to espressif team, because i dont see any option to setup tx power in esp-idf stack.

[nkolban]

While I believe you are after the function on Arduino BLE, we have implemented a solution for ESP-IDF. What this means is that the next time we cut an Arduino build (or if you build an Arduino BLE library yourself) it should be present. We have implemented:

BLEDevice::setPower(powerLevel)

This sets the "default" power level of the ESP32. The available choices are as documented here:

http://esp-idf.readthedocs.io/en/latest/api-reference/bluetooth/controller_vhci.html?highlight=esp_ble_tx_power_set#_CPPv220esp_ble_tx_power_set20esp_ble_power_type_t17esp_power_level_t

We haven't tested these yet but the code changes compile cleanly.

[d3cline]

I tried building from source and adding this, but I can't seem to figure it out, what am I doing wrong?

The file states,

/**
 * @brief Set the transmission power.
 * The power level can be one of:
 * * ESP_PWR_LVL_N14
 * * ESP_PWR_LVL_N11
 * * ESP_PWR_LVL_N8
 * * ESP_PWR_LVL_N5
 * * ESP_PWR_LVL_N2
 * * ESP_PWR_LVL_P1
 * * ESP_PWR_LVL_P4
 * * ESP_PWR_LVL_P7
 * @param [in] powerLevel.
 */

So I add,

BLEDevice::setPower(ESP_PWR_LVL_P1);
which renders,

In file included from /home/d3cline/devl/Arduinos/Luci-ESP32/Luci-ESP32.ino/Luci-ESP32.ino.ino:23:0:
/home/d3cline/Arduino/libraries/ESP32_BLE/src/BLEDevice.h: In function 'void setup()':
/home/d3cline/Arduino/libraries/ESP32_BLE/src/BLEDevice.h:56:14: error: 'static void BLEDevice::setPower(esp_power_level_t)' is private
  static void setPower(esp_power_level_t powerLevel);
              ^
Luci-ESP32.ino:101: error: within this context
   BLEDevice::setPower(ESP_PWR_LVL_P1);
                                     ^
exit status 1
within this context

I understand the general error and can read the h and cpp file for BLEDevice, but I don't understand why I suppose, where would I specify it in arduino if it is a private function in the library?

[chegewara]

You do nothing wrong. For some reason, @nkolban, this is private function https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/BLEDevice.h#L56

[d3cline]

Since it was a private function I decided to just edit line 272 of BLEDevice.cpp,

esp_err_t errRc = ::esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_DEFAULT, ESP_PWR_LVL_P1);

This is of course very hacky, but it builds. Will report my findings if it fixes radio issues.

[d3cline]

Adjusting these values does seem to change dBm using nfc toolbox to verify, and it seems to reduce the bug I was having, fyi.

[chegewara]

I did quick fix and PR is ready to merge. Thanks for finding it.

[zoobab]

[chegewara]

[Andreafoxalarm]

[chegewara]

[adityathakekar]

[chegewara]

[adityathakekar]

[chegewara]

[adityathakekar]

[TheUruguayo]

[chegewara]

[TheUruguayo]

[chegewara]

[TheUruguayo]

[chegewara]

[TheUruguayo]