https://devzone.nordicsemi.com/f/nordic-q-a/16016/s130-long-characteristic-valuesHi, I&#39;m facing a little problem with custom service characteristic. I&#39;ve set char settings as follows attr_char_value.init_len = sizeof(uint8_t); attr_char_value.init_offs = 0; attr_char_value.max_len = 5; attr_char_value.p_value = NULL; en-USTelligent Community 13Mon, 05 Sep 2016 12:14:41 GMThttps://devzone.nordicsemi.com/thread/61090?ContentTypeID=1Mon, 05 Sep 2016 12:14:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:899d4016-ac10-4f98-8081-857ca03b3b83Petter Myhre<p>I see.</p> <p>When you use BLE_GATTS_VLOC_USER the attribute Value is located in user memory. This requires you to maintain a valid buffer through the lifetime of the attribute, since the stack will read and write directly to the memory using the pointer provided in the APIs.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/61089?ContentTypeID=1Mon, 05 Sep 2016 11:27:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:630213b2-5c35-4f64-9073-faa3d2e951bfwizath<p>The main problem was BLE_GATTS_VLOC_USER setting. When changed to BLE_GATTS_VLOC_STACK everything works fine.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/61086?ContentTypeID=1Mon, 29 Aug 2016 11:58:31 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3ee86731-16f2-4ed7-8bc4-7c3890d0baf8Petter Myhre<p>It should work. As long as you don&#39;t use a len larger than 5. Are you checking the returned error code of sd_ble_gatts_value_set()? Is it 0x00000000 (NRF_SUCCESS)?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/61088?ContentTypeID=1Fri, 26 Aug 2016 21:08:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ce020021-72e4-4b12-8728-f31758d59da3wizath<p>len is simple uint8 value and data is uint8_t *. i&#39;m checking it with logging and everything is fine.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/61087?ContentTypeID=1Fri, 26 Aug 2016 14:37:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:91abb18b-ce4c-4c47-b6b1-35d007f5a72ePetter Myhre<p>Strange. What are the values of len and data?</p><div style="clear:both;"></div>