https://devzone.nordicsemi.com/f/nordic-q-a/66257/how-to-increse-the-packet-length-of-gzllhi im use nrf52840 as a gazell device which run the demo \nRF5_SDK_16.0.0_98a08e2\examples\proprietary_rf\gzll\gzp_desktop_emulator\pca10056 ,and use nrf24lu1p (\nrfready_desktop_2_v3.0.0\source_code\nrfready_desktop_dongle\projects\nrfready_desktopen-USTelligent Community 13Wed, 23 Sep 2020 12:06:55 GMThttps://devzone.nordicsemi.com/thread/271079?ContentTypeID=1Wed, 23 Sep 2020 12:06:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:31aae0d2-0168-4a47-b4cc-e8ac9186fbadKenneth<p>Hi,</p> <p>From gzp.h I can find that:</p> <p><pre class="ui-code" data-mode="c_cpp">#define GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID 1 ///&lt; &quot;Encrypted user data&quot; packet, validation ID position #define GZP_CMD_ENCRYPTED_USER_DATA_PAYLOAD ((GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)) ///&lt; &quot;Encrypted user data&quot; packet, user data position #define GZP_ENCRYPTED_USER_DATA_PACKET_OVERHEAD ( GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH) ///&lt; &quot;Encrypted user data&quot; packet, packet overhead length #define GZP_ENCRYPTED_USER_DATA_MAX_LENGTH (17 - GZP_ENCRYPTED_USER_DATA_PACKET_OVERHEAD) ///&lt; &quot;Encrypted user data&quot; packet, max payload length </pre></p> <p>This should mean that you can send 17 - 1 - 3 = 14 bytes encrypted packet using&nbsp;for instance&nbsp;gzp_crypt_data_send(payload, GZP_ENCRYPTED_USER_DATA_MAX_LENGTH).</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>