CCS/CC2640R2F: Need support in understanding Powel Level in BLE

For simple_peripheral example, it will be in STANDBY mode when there is nothing to handle. When there is anything to process, it will be waken up to Active mode.

Hi,

what will default (in code of simple peripheral or in TI stack) transmit power level when we dotn set any power level in application explicitly,

Can you share the value in dBm and also the place where this default value is defined.

Also if we want to change it in future, how can we do it from application and what is the right place in the init sequence to call this.

Hi Jenny T,

I have tried to edit the value of "DEFAULT_TX_POWER" from 7 to 8.

// Default Tx Power Index
#define DEFAULT_TX_POWER 8//7

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How to confirm that the dB value is actually changed or not?

Is there any application that can show the power level?

Regards,

Saurav

Hi Saurav,

I recommend using a power analyzer to accurately see the change in TX power. You could potentially utilize the built in CCS tool EnergyTrace to see differences in power measurements when testing different TX power values. However, I still recommend a power analyzer to be the most effective in getting accurate measurements of the TX power level specifically.

Best Regards,

Jenny

Hi Jenny T,

I  have checked the tool you have mentioned in the last comment.

In that also the dB value is not shown. Please help me in this issue.

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Doubt:

As we know that the default dB value is 0dB.

But when in that case when I am seeing the name of bluetooth device on the nrf-connect app, then the application is showing the dB value as  ~ (-50dB).

Below is the image showing the dB value in the nrf-connect app.

And when I am changing the default value to a different dB value --> In this case also the same dB level is shown on the nrf-connect app.

Why is this so?

Regards,

Saurav

Hi Saurav,

When using EnergyTrace, you will only be able to see power measurements such as change in current but not specifically TX power. I strongly recommend using a power analyzer if you need to see the exact TX power measurement.

The nrf-connect app displays the RX power measurement not the TX power.

Best Regards,

Jenny

Hi,

When you set the TX Power it does not reflect at nRF Connect App.

-kel

Hi Jenny T,

So, there is only one way to verify that the value of TX dB level is by using power analyzer -> is it a HW device?

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I want to ask one more thing, I have changed the value of "DEFAULT_TX_POWER" from 7(Default) to 8.

// Default Tx Power Index
#define DEFAULT_TX_POWER 8

* previously it was 7 and I have changed it to 8.

Below image states what the values 7 & 8 stands for:

So, Can you please verify that this change in the code is enough to change the Tx dB value for the BLE device?

Regards,

Saurav

Hi Saurav,

Yes I would suggest using a power analyzer for an accurate measurement.

When DEFAULT_TX_POWER is set to 8, it chooses the 8th element in the TxPowerTable (found in ICallBLE/ble_user_config.c). This is TX_POWER_1_DBM as seen in the image below.

Yes this change should be sufficient in changing the Tx power value.

Best Regards,

Jenny

Thanks a lot, Jenny T for confirming.

Regards,

Saurav

Hi Saurav,

No problem! Please let me know if you have any additional questions regarding this topic.

Best Regards,

Jenny