https://devzone.nordicsemi.com/f/nordic-q-a/14776/how-can-i-get-primary-service-which-i-don-t-knowHi. I&#39;m using PCA10028, SDK10.0.0, S130 and &quot;ble_app_uart_c&quot; as reference. As &quot;ble_app_uart_c&quot; source code, it already knows Service UUID. uint32_t ble_nus_c_init(ble_nus_c_t * p_ble_nus_c, ble_nus_c_init_t * p_ble_nus_c_init) { ...... uart_uuiden-USTelligent Community 13Mon, 27 Jun 2016 10:16:20 GMThttps://devzone.nordicsemi.com/thread/56423?ContentTypeID=1Mon, 27 Jun 2016 10:16:20 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b9f1dc46-a990-493a-be49-c856985fd91eshibshab<p>Discovering the contents of the peripheral database is in general called &quot;GATT Service Discovery&quot;, and there are several GATT procedures defined for doing this.</p> <p>A detailed description of these procedures can be found in the <a href="https://www.bluetooth.org/DocMan/handlers/DownloadDoc.ashx?doc_id=286439&amp;_ga=1.43215590.274512996.1465989578">Bluetooth Specification</a> Volume 3, Part G, Chapter 4 - &quot;GATT Feature Requeriments&quot;.</p> <p><strong>To answer your question</strong>: The S130 SoftDevice has API calls for most several of these procedures. To discover the primary services, simply perform the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s130.api.v2.0.0/group___b_l_e___g_a_t_t_c___f_u_n_c_t_i_o_n_s.html?cp=3_6_2_1_0_2_2_2_6#gaa778ccc1990e05fffa4aaf304c95e614">primary services discovery</a> procedure.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/56422?ContentTypeID=1Mon, 27 Jun 2016 09:53:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d1c0a0c4-5ef6-4264-a83e-ae8fdb7f5a43Petter Myhre<p>Could you elaborate a bit on your application? Also, you may find <a href="https://devzone.nordicsemi.com/question/15930/s130-custom-uuid-service-discovery/">this</a> question helpful.</p><div style="clear:both;"></div>