https://devzone.nordicsemi.com/f/nordic-q-a/14114/ble-notification-not-confirmed-on-androidHi, I&#39;m working on an application with S130 central (client) connecting to an Android peripheral device (server). I have two characteristics on peripheral device, one for write and one for notify. I can successfully register on notification and writeen-USTelligent Community 13Tue, 31 May 2016 07:46:25 GMThttps://devzone.nordicsemi.com/thread/53945?ContentTypeID=1Tue, 31 May 2016 07:46:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:431dbecb-d583-4c9e-af79-1a0386a229c8A_Caron<p>I finally found the problem using a sniffer It&#39;s seems that Android always send the first notification as indiaction but I didn&#39;t handle these.</p> <p>So i just add</p> <pre><code>if (pHVXEvent-&gt;type == BLE_GATT_HVX_INDICATION) { sd_ble_gattc_hv_confirm(pWpd-&gt;conn_handle, pHVXEvent-&gt;handle); } </code></pre> <p>And it&#39;s work properly !</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/53944?ContentTypeID=1Tue, 31 May 2016 07:43:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:15d0ca90-18d7-4c01-8635-ab8be5e32f7dA_Caron<p>Yes notify is enable on Android and I subscribe on it writting BLE_GATT_HVX_NOTIFICATION on CCCD handle</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/53943?ContentTypeID=1Fri, 27 May 2016 12:14:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5b02edbe-0a7a-41d2-8d9f-6d1bef6b1c8arun_ar<p>Did you enable notfication by writing to the CCCD&#39;s when using the S130 as central device?</p><div style="clear:both;"></div>