Distance Mesurement not working in after connection nrf_dm

[syed_]

struct bt_le_adv_param *adv_param = &adv_param_conn;

static struct bt_scan_init_param scan_init = {
     .connect_if_match = 1,
     .scan_param = &scan_param,
     .conn_param = NULL
     };

basically, I want to use dm feature in connection-oriented communication.
not in connection less, and I want to connect 1 central to 4 peripheral and measure distance.

Can you suggest me where to make other changes?

[Amanda Hsieh]

Hi, 

May I know why you want to use the dm feature in connection-oriented communication?

The current nRF Distance Measurement with Bluetooth LE discovery can measure distance for 4 different devices without connection. 

Regards,
Amanda H.

[syed_]

Hi,

So, the base feature is to measure the distance and i have some data which should be exchanged between a peripheral to central and central to all connected peripheral, this would happen only using GATT write and notify/indicate.

That is the reason i need connection-oriented communication.

Regards,

Syed

[syed_]

any updates.

[Amanda Hsieh]

Hi, 

BLE scanning and advertising are used in the Bluetooth: nRF Distance Measurement with Bluetooth LE discovery sample, in order to synchronize when to initiate distance measuring on the two devices. After the BLE synchronization, one device initiates as reflector and one device initiates as initiator, and the ranging is performed.

You could modify the sample to make the device only advertise on the peripheral side and work with another device that has scanning and advertising to measure distance. Here is a similar case. Hope it can help. 

-Aamdna H.

[syed_]

Hi,

As you have a reference to a "similar case" than is not the actual case, Distance measurement is working fine with its connection less communication even if the peripheral and central are separated,

The major issue Iam facing is measurement is not working in connection-oriented communication.

please take this in priority coz deadline has already been over.

-Syed

[syed_]

Hi, Amanda Hsieh 

Any updates.

[Amanda Hsieh]

Hi, 

You will need to find a way to synchronize the initiator and reflector, for example by starting the ranging at an offset from a connection event. It might be able to use radio notifications for syncing: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/mpsl/doc/radio_notification.html You will also need to find another way of exchanging the random seed that is used to generate for example the channel hopping sequences during the ranging. Should be possible to do over the connection.

-Amanda H.

[syed_]

Hi, Amanda Hsieh 

can you please help me with this:

Session 3.sal

I'm triggering  dm_add_request(); after gatt_write(); on central side and at the peripheral side once the write callback is received the dm_add_request(); is triggered on peripheral side, as you have mention above to synchronize the initiator and reflector, but it is not possible due to ble radio on and off, is there any other way sync these 2 devices

Best regards,

syed

[syed_]

Is there any chance to get connection call back every time the central and peripheral radios are connected, if yes please help me out. 

[Amanda Hsieh]

You can refer to the connection callback used in the https://github.com/nrfconnect/sdk-nrf/tree/main/samples/bluetooth 

-Amanda H.