https://devzone.nordicsemi.com/f/nordic-q-a/17721/cannot-reconnect-automatically-with-a-bonded-device-after-disconnectHi: I referenced to the example&quot;ble_app_hids_keyboard&quot;,and finally,I can reconnect the phone automatically.But that project was a little complex,so I simplify the &quot;service_init();&quot; function. At last,the project only includes a service with two characteristicsen-USTelligent Community 13Wed, 16 Nov 2016 07:31:29 GMThttps://devzone.nordicsemi.com/thread/68202?ContentTypeID=1Wed, 16 Nov 2016 07:31:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a8c779eb-864a-401e-84b9-d695f55daeaeFormerMember<p>HID profile devices, keyboards and mouse, and are typically handled by the OS (Android, iOS, Windows(?)) automatically. The way these OS&#39;s recognize a HID device is that the services have the HID UUIDs defined by Bluetooth SIG. If changing UUIDs on a HID device, the OS&#39;s will not longer recognize the device as a HID device. From the OS point of view that device could have any functionality. Therefore, handling of that HID device with changed UUIDs has to be done &quot;manually&quot;, using an app or connect from the Bluetooth settings.</p><div style="clear:both;"></div>