Bluetooth 5.4 on Nordic platform

[Tony Cheng]

Hi. I have some question regarding to Bluetooth 5.4 on Nordic platform

1. Can Nordic platform do Advertising Coding Selection? I saw some old old issue that the device can only transmit with S=8 when using the LE Coded PHY.  

2. Is there an article summarized the compatibility of Nordic devices with Bluetooth 5.0, Bluetooth 5.1, Bluetooth 5.2, Bluetooth 5.3, Bluetooth 5.4? 

Thank you so much. 

[Susheel Nuguru]

1. Can Nordic platform do Advertising Coding Selection? I saw some old old issue that the device can only transmit with S=8 when using the LE Coded PHY.  

S=8 and S=2 works on our latest nRF Connect SDK latest versions.

2. Is there an article summarized the compatibility of Nordic devices with Bluetooth 5.0, Bluetooth 5.1, Bluetooth 5.2, Bluetooth 5.3, Bluetooth 5.4? 

Nordic is compatible and implements all the features required by BLE new versions. We do not have a compatibility and comparison matrix by itself, but there are many external blogs summarizing this. For example this one. If you want to know any compatibility of any specific feature in a specific version of BLE with nRF devices, then please be specific and we can try to find the relevant info.

[Tony Cheng]

Thanks for the quick response. Susheel. It helps a lot. 

May I ask how to choose to advertise in S=2 or S=8 with LE coded PHY?

Also, how to add a characteristic to the GAP service? I am trying to create the security level characteristic.

I am using the SDK v2.7.0.

Thank you.

[Susheel Nuguru]

Tony, 

sorry was away half of the day yesterday.

Tony Cheng said:

May I ask how to choose to advertise in S=2 or S=8 with LE coded PHY?

Something like below maybe in the connected callback or wherever it seems fit in your application.

param.options = BT_CONN_LE_PHY_OPT_CODED_S2;
param.pref_tx_phy = BT_HCI_LE_PHY_CODED;
param.pref_rx_phy = BT_HCI_LE_PHY_CODED;

err = bt_conn_le_phy_update(conn, &param);
if (err) {
    printk("Update PHY error: %d\n", err);
}

Tony Cheng said:

Also, how to add a characteristic to the GAP service? I am trying to create the security level characteristic.

Please do not mix many questions in one into a thread. This one is a basic question that has been asked before. But let me try to explain this one.

You can add a characteristic with security to a service by defining the characteristic and its properties, and then adding it to the service. Here's a general example of how to do it:

#include <bluetooth/gatt.h>

/* GATT service declaration */
BT_GATT_SERVICE_DEFINE(my_service,
    BT_GATT_PRIMARY_SERVICE(&my_service_uuid),
    BT_GATT_CHARACTERISTIC(&my_char_uuid.uuid, &my_char_props,
                           BT_GATT_PERM_READ_AUTHEN,
                           read_callback, write_callback, &my_value),
    ...
);

BT_GATT_SERVICE_DEFINE is a macro that defines a GATT service. BT_GATT_PRIMARY_SERVICE is a macro that defines a primary service. BT_GATT_CHARACTERISTIC is a macro that defines a characteristic.

my_service_uuid and my_char_uuid are the UUIDs of the service and the characteristic, respectively. my_char_props are the properties of the characteristic. BT_GATT_PERM_READ_AUTHEN is the permission for the characteristic, which requires authentication for read access. read_callback and write_callback are the read and write callbacks for the characteristic. my_value is the initial value of the characteristic.

Please note that the actual code may vary depending on your application requirements and the version of Zephyr you are using.

For more information, you can refer to the Zephyr documentation.

For adding a characteristic with a specific security level, you can set the permissions of the characteristic to BT_GATT_PERM_READ_ENCRYPT or BT_GATT_PERM_READ_AUTHEN for read access, and BT_GATT_PERM_WRITE_ENCRYPT or BT_GATT_PERM_WRITE_AUTHEN for write access. These permissions require encryption or authentication for read or write access, respectively.

Also check if these pages on Security is of some help.

Zephyr > Security > Secure Coding

Zephyr > Security > Zephyr Security Overview

[Tony Cheng]

Thank you so much. Susheel.

You saved my day. 

[Susheel Nuguru]

glad that the reply helped. Can yo uplease mark my reply as verified answer so that it could help other forum members?