https://devzone.nordicsemi.com/f/nordic-q-a/10277/how-to-change-the-data-length-of-ble-notificationThe maximum data length of a characteristic is 9, and I use the follow function to send the notification to a client uint32_t dxs_send(dr_ble_dxs_t * p_dxs, uint8_t * p_data, uint16_t length) { uint32_t ret_code; ble_gatts_hvx_params_t hvx_params;en-USTelligent Community 13Thu, 19 Nov 2015 11:03:30 GMThttps://devzone.nordicsemi.com/thread/38143?ContentTypeID=1Thu, 19 Nov 2015 11:03:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bdf16f0f-1852-4ae8-ad85-ae68aa4016bcStefan Birnir Sverrisson<p>Hi</p> <p>I want to provide basically the same answer as shibshab provided, with little more specifics. This is how the length parameters are presented in the BLE examples in the nRF51 SDK:</p> <pre><code>attr.max_len attr.init_len attr_md.vlen </code></pre> <p>which define the maximum length for the characteristic, initial length, and if the characteristic should have variable length or not. Modify these three as needed.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/38144?ContentTypeID=1Thu, 19 Nov 2015 07:33:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3b1c2863-3b0a-425a-afb6-b2793b5bc8a2shibshab<p>In ATT, an attribute can have either fixed or variable length. This implies that the client you are sending notifications to need to have configured the characteristic value attribute with variable length.</p> <p>When you create the characteristic of which you are sending the value, make sure you set the property Variable Length to 1.</p><div style="clear:both;"></div>