what is the conn_handle? And when does it use?

RE: what is the conn_handle? And when does it use?

JoonDong — Fri, 10 Feb 2017 14:54:55 GMT

Thank you for your answer. That is very helpful.

RE: what is the conn_handle? And when does it use?

Hung Bui — Fri, 10 Feb 2017 14:08:20 GMT

Yes, it's assigned by softdevice each connection. If you are using nRF5 as a peripheral , you simply only have conn_handle = 0x0000 as there is only one connection at a time.

RE: what is the conn_handle? And when does it use?

JoonDong — Fri, 10 Feb 2017 14:06:54 GMT

So is it just assigned per each connection?

RE: what is the conn_handle? And when does it use?

JoonDong — Fri, 10 Feb 2017 13:56:25 GMT

I already checked p_ble_evt->evt.gap_evt.conn_handle during debugging, but value is always 0xFFFF or 0x0000..

RE: what is the conn_handle? And when does it use?

Hung Bui — Fri, 10 Feb 2017 13:19:49 GMT

What do you mean by this "when connection event about second connection occurs " ? You don't have to guess/assume the conn_handle, you simply find it in the event you got, for example in BLE_GAP_EVT_CONNECTED event , look for p_ble_evt->evt.gap_evt.conn_handle, as Alex suggested.

RE: what is the conn_handle? And when does it use?

JoonDong — Fri, 10 Feb 2017 13:11:45 GMT

So is conn_handle 0x0001 when connection event about second connection occurs if second connection is established?

RE: what is the conn_handle? And when does it use?

Alex — Fri, 10 Feb 2017 12:44:24 GMT

Connection handle is available in p_ble_evt->evt.gap_evt.conn_handle on BLE_GAP_EVT_CONNECTED event. You need to save it during current connection and use in function calls such as sd_ble_gatts_hvx(). When you receive BLE_GAP_EVT_DISCONNECTED then you should update variable to BLE_CONN_HANDLE_INVALID. Variable has to be global, make sure you don't use local variable with the same name.

RE: what is the conn_handle? And when does it use?

Hung Bui — Fri, 10 Feb 2017 12:39:25 GMT

BLE_GATT_HANDLE_INVALID is for attribute handle, not connection handle. The first connection will have value of 0x0000. So it's normal. If you have more than one connection at the same time, for example in a central application with more than one peripheral, you will have different connection handles for different connections.

Do you have trouble using sd_ble_gatts_hvx() ?