https://devzone.nordicsemi.com/f/nordic-q-a/82525/how-to-developp-bootloader-on-arduino-nano-33-bleHi, I&#39;m looking for a solution to update my program with BLE. I need to do it with a mobile app developped in Flutter. I found the Flutter library to flash the Arduino ( flutter_nordic_dfu ). But with the original bootloader, I can&#39;t use this libraryen-USTelligent Community 13Thu, 09 Dec 2021 08:05:10 GMThttps://devzone.nordicsemi.com/thread/342634?ContentTypeID=1Thu, 09 Dec 2021 08:05:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e90c1129-2f77-4b49-ba22-bc1c5a4496c7Einar Thorsrud<p>Hi,</p> <p>I am not familiar with the Arduino nano 33 BLE specifically,&nbsp;nor which SW platform you are using. The <a href="https://github.com/fengqiangboy/flutter-nordic-dfu">flutter_nordic_dfu </a>seems to be a third party flitter implementation for a Nordic DFU master. I cannot say if or how well this works (perhaps someone else on the forum can comment?), but in principle it looks like it should work with the secure bootloader in the nRF5 SDK.</p> [quote user=""]What can I do to be able to flash the program with BLE ? Is there a way to custom the bootloader&nbsp;and from&nbsp;what files ? I have a J-Link mini EDU to flash Bootloader.&nbsp;[/quote] <p>Assuming you use the normal SDK bootloader and not something Arduino specific I suggest that you first work with a <a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/ble_sdk_app_dfu_bootloader.html">BLE secure bootloader example</a> and mobile app we provide to have a known working starting point. You man also find <a href="https://devzone.nordicsemi.com/guides/short-range-guides/b/software-development-kit/posts/getting-started-with-nordics-secure-dfu-bootloader">Getting started with Nordic&#39;s Secure DFU bootloader, a step by step guide</a>&nbsp;useful.</p> <p>If you are using a bootloader modified by Arduino or Adafruit or similar I suggest you ask in their forums for details about that.</p><div style="clear:both;"></div>