https://devzone.nordicsemi.com/f/nordic-q-a/71423/add-scan-response-data-to-dfu-bootloaderHello together, I try to add some bytes for scan response data in DFU bootloader. So I changed the file components/libraries/bootloader/ble_dfu/nrf_dfu_ble.c to add 6 bytes: But then, the bootloader does not advertize. If I remove the 6 linesen-USTelligent Community 13Mon, 08 Feb 2021 19:37:54 GMThttps://devzone.nordicsemi.com/thread/293431?ContentTypeID=1Mon, 08 Feb 2021 19:37:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:570cebf3-f5f5-496f-8c18-9901bd7fbe7bSigurd<p>Hi,</p> <p>You can&#39;t just add&nbsp;<span>arbitrary bytes to a advertising/scan-response packet like this. It follows a certain format. See <a href="https://www.novelbits.io/bluetooth-low-energy-advertisements-part-2/">this post</a>. Based on the flags and data you provide, the device that scans these packets decodes and displays the data in different ways. In the nRF5 SDK, we have the function&nbsp;ble_advdata_encode() that helps you encode the data in the correct format.</span></p> <p><span>You have&nbsp;m_enc_resp_data[0]=0x0A , so you are indicating that you have 0x0A length of data, but at the same time&nbsp;you are setting&nbsp;scan_rsp_data.len to 6. Try setting&nbsp;m_enc_resp_data[0] to 0x05 instead.</span></p><div style="clear:both;"></div>