Unable to receive notifications and write certain characteristics to peripheral

[Segun Ilori]

I am currently developing a central device based on the NRF52832. I am able to discover and get handles to all the services and characteristics of interest on the peripheral.

However, I do not receive  notifications from all characteristics of interest (some work). I am also unable to successfully any write characteristics despite getting BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE.

Do I need to get handles to characteristics on the project? Any suggestions? 

(BTW everything works fine on nRF Connect)

[run_ar]

Have you tried to capture a sniffer trace to see what is happening on air? I would guess that maybe you did not discover all the characteristics? and you are not getting notifications, are you sure you enabled notifications for all characteristics?

[Segun Ilori]

I have been successful in writing to all the characteristics. I changed the write_op parameter to BLE_GATT_OP_WRITE_REQ and when a response handler was triggered did nothing else. Before, I wrote again using the BLE_GATT_OP_EXEC_WRITE_REQ.

Concerning notifications, the peripheral sends them for sure. but somehow the BLE_GATTC_EVT_HVX is not triggered. I have also taken care to use sd_ble_gattac_hv_confirm when necessary. Do I need to carry out any specific ation for the BLE_GATTC_EVT_HVX to be triggered? 

[run_ar]

first you have to enable notification by writing to the cccd. which is what I assume you are doing with the writes (you will get an error on the gatt server if you try to send notifications (sd_ble_gatts_hvx) when the peer is not subscribing). Apart from that you should get the BLE_GATTC_EVT_HVX on the client. sd_ble_gattc_hv_confirm is only needed if you are using indications.

have you checked that you have registered your service as an observer in sdh?