BLE5.0 Range Settings

[zcmm]

SDK: 17.0.0

Softdevice : S140

Example:     ble_app_blink

I modify this example to long range adverting mode,and have some questions as follow:

(1)  the device can not connect for nrf connect app when the advertings parameters as follow:

     adv_params.primary_phy     = BLE_GAP_PHY_CODED; (change to BLE_GAP_PHY_1MBPS, nrf connect app can connect)
     adv_params.secondary_phy   = BLE_GAP_PHY_CODED;
     adv_params.properties.type = BLE_GAP_ADV_TYPE_EXTENDED_CONNECTABLE_NONSCANNABLE_UNDIRECTED;

(2) What is the difference between these two broadcast parameter setting methods?

     First settings：

          adv_params.primary_phy     = BLE_GAP_PHY_1MBPS;
          adv_params.secondary_phy   = BLE_GAP_PHY_CODED; 

     second settings：

          adv_params.primary_phy     = BLE_GAP_PHY_CODED;
          adv_params.secondary_phy   = BLE_GAP_PHY_CODED; 

[Einar Thorsrud]

Hi,

Both configurations are valid. In the first configuration you are advertising on the 1 M PHY (BLE_GAP_PHY_1MBPS) and in the second you are advertising with coded PHY (BLE_GAP_PHY_CODED). Which central device are you testing with? Are you sure it supports scanning and establishing a connection using coded PHY?

[zcmm]

hi，

Yes，I am sure the phone (HUAWEI P40 PRO)supports scanning and establishing a connection using coded PHY.

Does this second setting make any difference to the range of distance?

[Einar Thorsrud]

Hi,

I do not have a HUAWEI P40 PRO so I cannot verify, but are you confident it supports establishing the connection on Coded PHY? Most phones (even new high-end models) only support establishing a connection on 1 MBps, and then changing to coded PHY.

The difference between using 1M PHY as primary instead of Coded is that in this case the 1M phy is used to establish connections, and this is also used to point to the secondary phy (coded, in this case). This approach is the most compatible. It has the downside that 1 M advertisement packets must be received, so it reduces the range before the connection can be established.