https://devzone.nordicsemi.com/f/nordic-q-a/1795/problem-with-notify-custom-and-standard-servicesHi, i took the example in AN36 (with the led but deleted the button stuff) and added the Battery Level service. Both are working fine together. On top of that I took the battery service and coustomized it like shown in the files attached. I added thisen-USTelligent Community 13Thu, 06 Mar 2014 12:23:40 GMThttps://devzone.nordicsemi.com/thread/7831?ContentTypeID=1Thu, 06 Mar 2014 12:23:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5a8f79cb-2c24-4c27-8d05-c75359404ef0Hung Bui<p>Karl, please upload your project. And please make sure you called sd_ble_gatts_hvx() to update (notify) the speed characteristic when the CCCD is enabled.</p><div style="clear:both;"></div>