How to set TX power in ADV and Scanning mode

RE: How to set TX power in ADV and Scanning mode

Vidar Berg — Wed, 29 Apr 2020 06:10:24 GMT

Hi Salman,

[quote user="salman"]Now I am able to reduce the TX power, now ever I am seeing spikes of current consumption going up to max 14.262 mA. Can you tell what are they? I am suspecting this might be scanning for scan request at this stage.[/quote]

Yes, this is the RADIO in RX mode. It is not affected by the TX power setting.

[quote user="salman"]but still there is no effect on the current consumption while scanning after using this function[/quote]

The RADIO is in RX when scanning. The -20 dBm will be used when sending out scan requests or initiating new connections.

Regards,

Vidar

RE: How to set TX power in ADV and Scanning mode

Salman — Tue, 28 Apr 2020 18:23:29 GMT

Hi,

Now I am able to reduce the TX power, now ever I am seeing spikes of current consumption going up to max 14.262 mA. Can you tell what are they? I am suspecting this might be scanning for scan request at this stage. See the below image.

Below is the previous reading before reducing TX power:

but still there is no effect on the current consumption while scanning after using this function

err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_SCAN_INIT, 0, -20);
APP_ERROR_CHECK(err_code);

Do I have to put this function before starting scanning?

Regards,

Salman

RE: How to set TX power in ADV and Scanning mode

Vidar Berg — Tue, 28 Apr 2020 06:36:25 GMT

Hi,

It doesn't look like the TX power changed based on the power profiler plot. Current peaks are close to what you can expect with 0 dBm and LDO regulator. You can play around with the Online power profiler here to see what the expected consumption is with different configurations: https://devzone.nordicsemi.com/nordic/power/

1. I'm not sure why the power settings are not being applied. Please try to add the code below after advertising init and see if you get the same result.

    err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, 0 /* Handle is always 0 with current Softdevices */, -20);
    APP_ERROR_CHECK(err_code);
    err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_SCAN_INIT, 0, -20);
    APP_ERROR_CHECK(err_code);

2. It's only measuring the VDD current going into the nRF51. LEDs and other external circuitries are excluded.

3. See the code snippet in point 1 above.