cannot update notification value

[Haruki Kawakami]

Once I call sd_ble_gatts_hvx() while ble connection handle is invalid(BLE_CONN_HANDLE_INVALID), I can never update notification value using sd_ble_gatts_hvx() though function result is NRF_SUCCESS.

Is this softdevice bug?

The expected operation is that the value can be updated whenever sd_ble_gatts_hvx() return NRF_SUCCESS.

7/19 22:01 sd_ble_gatts_hvx() returns NRF_SUCCESS, but the value client get is the same as the first value I set with sd_ble_gatts_hvx() while ble connection handle is invalid.

[endnode]

Not really, sd_ble_gatts_hvx() returning NRF_SUCCESSonly means that packet got stored into one of Tx buffers inside Soft Device. Once it goes really out you will get specific event (in the latest SDK it's called BLE_GATTS_EVT_HVN_TX_COMPLETE) and only then another Handle Value Notification packet gets out. Note that there isn't only one Tx buffer in the SD so you can "stack" at least 6 packets in advance. Apart from this all works without problems, no bug known that SD would not transport data out or that you wouldn't be able to transport other data then first string you provide to the function. Are you sure it's not bug in your code before calling sd_ble_gatts_hvx() function?

[Hung Bui]

You mean updating the value but not sending notification ? If you want to update the value of the characteristic locally, please call sd_ble_gatts_value_set() instead.

[Haruki Kawakami]

No. I want to call sd_ble_gatts_hvx() regardless ble connection handle.

[Haruki Kawakami]

Even if ble connection is valid and client enable CCCD, I can't transport data other than first string I provide to the function once I call sd_ble_gatts_hvx() while ble connection handle is invalid.

[endnode]

If connection handle is invalid then calling this function doesn't make any sense.