https://devzone.nordicsemi.com/f/nordic-q-a/49927/ble-advertising-adv---uuid-as-connection-criteriaHey, I would like to connect the &quot;image_transfer_demo&quot; example (running on a nrf52840) with the &quot;Nordic_UART_Service&quot; (BLE central) example (running on another nrf52840). As I found, the Nordic_UART_Service central scans the advertising BLE peripheralsen-USTelligent Community 13Thu, 18 Jul 2019 13:18:17 GMThttps://devzone.nordicsemi.com/thread/199302?ContentTypeID=1Thu, 18 Jul 2019 13:18:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d4edb0c3-4761-4ba4-83bb-74d1c1792977AlexW<p>I found my problem:<br />I focused on the Service UUIDs rather than the BASE_UUIDs of the devices.&nbsp;<br />Now the boards are connecting without problems.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/199141?ContentTypeID=1Thu, 18 Jul 2019 08:16:31 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6dc7481b-1247-4047-8196-f750b22fd5d5AlexW<p>The scanning and advertising LEDs (LED_0) are just&nbsp;flashing without any discontinuity.&nbsp;<br />So I assume they do not attempt to connect.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/199015?ContentTypeID=1Wed, 17 Jul 2019 13:40:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:09b18275-3593-4bbf-8b5d-3e3a02d82cb5awneil[quote userid="78915" url="~/f/nordic-q-a/49927/ble-advertising-adv---uuid-as-connection-criteria"]the NUS_Central will only connect to the NUS_Peripheral but won&#39;t connect to the Image_Transfer Service[/quote] <p>Does it not attempt to connect at all, or does it try and then fail ?</p><div style="clear:both;"></div>