[NRF52833] [Bluetooth Mesh mode] set Tx power

[Tien_Nguyen]

Hello developers,
I am using nRF52833 chip for Bluetooth Mesh sensor application
In Kconfig I am setting TX POWER transmitter power at +8dbm. According to the device specifications it can reach up to 8dBm with a current consumption of 15mA.
But now I only measure 11mA, corresponding to 0dbm.
I have used hci_pwr_ctrl example but set/get failed.

Hope to receive support to be able to increase the transmission capacity to 8dbm. More about my project: Zephyr RTOS + nRF Connect SDK 2.0, mesh sensor server, LPN is not implemented.

Thanks in advance,

[AHaug]

Hi,

You could try to use CONFIG_BT_CTLR_TX_PWR_PLUS_8=y to change the it to 8dB. There are also similar configs to change it to other values, such as CONFIG_BT_CTLR_TX_PWR_MINUS_4=y if you want to set it to -4 instead of +8

Kind regards,
Andreas

[Tien_Nguyen]

I tried the config but nothing changed, I tried measuring the RSSI between 0dbm and 8dbm also no change at all. 0dbm and 8dbm is a very large range so it can be concluded that this setting does not give me the results I want.

[AHaug]

Did you also include the dependencies that the config setting requires?

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/kconfig/index.html#!CONFIG_BT_CTLR_TX_PWR_PLUS_8

Kind regard,
Andreas

[Hieu]

Hi TienNguyen,

In NCS v2.0.2 and older, CONFIG_BT_CTLR_TX_PWR_PLUS_8 and similar Kconfig CONFIG_BT_CTLR_TX_PWR_* don't work correctly.

You can refer to Known Issue DRGN-15903 here Known issues — nRF Connect SDK 2.0.2 documentation (nordicsemi.com)

If you have to stay with NCS v2.0, please set TX power dynamically instead. The following sample will show you how to do it: Bluetooth: HCI Power Control — Zephyr Project Documentation (nordicsemi.com)

If you can upgrade to NCS v2.1.0 or newer, the Kconfig should work correctly.

Sorry for the inconvenience.

Hieu

[Tien_Nguyen]

Hieu said:

CS v2.1.0 or newer, the Kconfi

Yes, i sucessed config TX power by change source in SDK few days ago.

In "nrf_radio.h" line 273-275, I remove:

#if defined(RADIO_TXPOWER_TXPOWER_Pos8dBm) || defined(NRFX_DOXYGEN)
NRF_RADIO_TXPOWER_POS8DBM = RADIO_TXPOWER_TXPOWER_Pos8dBm, /**< 8 dBm. */
#endif

And replace by:

NRF_RADIO_TXPOWER_POS8DBM = RADIO_TXPOWER_TXPOWER_Pos8dBm,

It work like a charm