BLE long range

[thang47]

Hi, I want use BLE long range in nrf52840, nrf connect SDK v2.4.0. Is there any example of ble long range?

Thanks.

[Hieu]

Hi thang47,

BLE Long Range is realized with Coded PHY. We provide a pair of samples for this:

Bluetooth: Central Heart Rate Monitor with Coded PHY — nRF Connect SDK 2.5.0 documentation (nordicsemi.com)

Bluetooth: Peripheral Heart Rate Monitor with Coded PHY — nRF Connect SDK 2.5.0 documentation (nordicsemi.com)

Hieu

[thang47]

Hi, Hieu.

Now I have 10 devices, can the central device connect to all 10 devices at the same time?

[Hieu]

Hi thang47,

Yes, the central device should be able to connect to all 10 devices at the same time. The upper limit is 20 for now.

I would also like to inform you that this question has been asked multiple times on DevZone, so please try to search for it using DevZone's search feature, or your favorite internet search engine, if you could.

Also, please remember that we try to keep each DevZone case focused on one topic. Therefore, if you have a new question on a different topic, please open a new case.

[thang47]

Hi Hieu, thank you for your answer.

I want to ask one more question: is the long range configuration in the example you give a speed of 125kbs or 500kbs?

[Hieu]

Hi thang47,

If you read the documentation of the samples, you can see that in the Testing section, the expected log is:

Connected: xx.xx.xx.xx.xx.xx (random), tx_phy 4, rx_phy 4

You can then find in the source code that the log line is produced in the connected() callback:

		phy_info = info.le.phy;
		printk("Connected: %s, tx_phy %u, rx_phy %u\n",
				addr, phy_info->tx_phy, phy_info->rx_phy);

If you the trace the declaration of the tx_phy, you can find how the value is defined:

struct bt_conn_le_phy_info {
	uint8_t tx_phy; /** Connection transmit PHY */
	uint8_t rx_phy; /** Connection receive PHY */
};

/** Connection PHY options */
enum {
	/** Convenience value when no options are specified. */
	BT_CONN_LE_PHY_OPT_NONE = 0,

	/** LE Coded using S=2 coding preferred when transmitting. */
	BT_CONN_LE_PHY_OPT_CODED_S2  = BIT(0),

	/** LE Coded using S=8 coding preferred when transmitting. */
	BT_CONN_LE_PHY_OPT_CODED_S8  = BIT(1),
};

From that, the PHY is Coded S8, so a speed of 125kbs.

[thang47]

Hi Hieu, Thanks for your answer.

Is it possible to configure in ble long range mode, broadcast beacon messages without connection?

[Hieu]

Hi thang47,

Yes, but I must stress once again that you will get faster answer and it will be more efficient for both of us if you try to look up the information first.