How to enable Coded PHY (Long Range) advertising on nRF54L15-DK using nRF Connect SDK 3.0.2?

[mertpalaoglu1]

I'm using the nRF54L15-DK with nRF Connect SDK 3.0.2, and trying to advertise using Coded PHY (Long Range).

My goal is to make the advertising signal continuously visible (not just in bursts) on a spectrum analyzer, with 8 dBm TX power, using Long Range (Coded PHY).

What I currently have:

Im using an inside sample of the sdk (hci_pwr_ctrl) and changed the code like that:

static const int8_t txpower[DEVICE_BEACON_TXPOWER_NUM] = {8};

static const struct bt_le_adv_param *param = BT_LE_ADV_PARAM(

    BT_LE_ADV_OPT_CONN | BT_LE_ADV_OPT_USE_IDENTITY

    | BT_LE_ADV_OPT_DISABLE_CHAN_38

    | BT_LE_ADV_OPT_DISABLE_CHAN_39,

    BT_GAP_MS_TO_ADV_INTERVAL(20),

    BT_GAP_MS_TO_ADV_INTERVAL(20), // I tried 1024 too.

    NULL

);

Problems:

• The signal appears only intermittently on the analyzer.

• Advertising seems to be using only 1M PHY, not Coded PHY.

My Questions:

1. What is the minimal correct setup to advertise over Coded PHY on the nRF54L15-DK? 

2. How can I make the signal appear continuously on a spectrum analyzer (without long silent gaps)?

3. Is there a sample or working snippet specifically for Coded PHY extended advertising I can reference?

4. Is there any sample that I can use to test the bluetooth long range, 8db tx power for 1 central and 1 peripheral nrf54l15 devices.   

Any guidance or working example would be greatly appreciated!

[Hieu]

Hi mertpalaoglu1,

What is the minimal correct setup to advertise over Coded PHY on the nRF54L15-DK? 

Is there a sample or working snippet specifically for Coded PHY extended advertising I can reference?

Is there any sample that I can use to test the bluetooth long range, 8db tx power for 1 central and 1 peripheral nrf54l15 devices.

Please refer to the Bluetooth: Peripheral Heart Rate Monitor with Coded PHY.

These Kconfigs in particular enable advertising over Coded PHY: https://github.com/nrfconnect/sdk-nrf/blob/v3.0.2/samples/bluetooth/peripheral_hr_coded/prj.conf#L16-L17

Source code showing how to start advertising can be found in main.c.

To fix TX power to 8dB, set CONFIG_BT_CTLR_TX_PWR_ANTENNA to 8.

How can I make the signal appear continuously on a spectrum analyzer (without long silent gaps)?

How long a silent gap are we talking about here?

If you use the nRF Connect app on your phone, what does it say the advertising interval is?

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You seem to expect to find all the advertising packets in channel 37. That is not the case. Please refer to the answer here:  Extended Advertising on Coded PHY Questions .

Hieu