https://devzone.nordicsemi.com/f/nordic-q-a/74616/add-16-bit-uuid-ble-standard-characteristicsHi, I&#39;ve been following below tutorial and everything works fine. https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-characteristics-a-beginners-tutorial However, I was not able to figure out how to modifyen-USTelligent Community 13Fri, 30 Apr 2021 17:58:12 GMThttps://devzone.nordicsemi.com/thread/307725?ContentTypeID=1Fri, 30 Apr 2021 17:58:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:34caa577-978d-483d-a9f5-82b70d28e7a8Marjeris Romero<p>Hi,</p> <p>You can take a look at how other 16-bit SIG GATT services are defined in the SDK, for example see how Battery Service is defined inside nRF5_SDK/components/ble/ble_services/ble_bas/ble_bas.c in nRF5 SDK v17.1.0, line 207:<br /><pre class="ui-code" data-mode="text"> // Add service BLE_UUID_BLE_ASSIGN(ble_uuid, BLE_UUID_BATTERY_SERVICE);</pre></p> <p>And <a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.0.2%2Fgroup___u_u_i_d___s_e_r_v_i_c_e_s.html&amp;anchor=ga4090520f3007fe6f90f06a6f4f8d5845">BLE_UUID_BATTERY_SERVICE</a> is defined to same 16-bit number as in the <a href="https://btprodspecificationrefs.blob.core.windows.net/assigned-values/16-bit%20UUID%20Numbers%20Document.pdf">16-bit UUID assigned numbers</a> document from Bluetooth SIG.</p> <p>I recommend just using the same template as with ble_bas.c for the GATT service you want to add.</p> <p>Best regards,</p> <p>Marjeris</p><div style="clear:both;"></div>