https://devzone.nordicsemi.com/f/nordic-q-a/118795/question-about-usb-flashingHello, I am a student currently working on my diploma thesis, which is focused on the Nordic nRF52840. I have designed a custom board that is functioning well. At the moment, I am flashing it using a J-Link programmer, but I would like to utilize theen-USTelligent Community 13Tue, 11 Feb 2025 08:38:35 GMThttps://devzone.nordicsemi.com/thread/522362?ContentTypeID=1Tue, 11 Feb 2025 08:38:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fca5e248-48d1-4e0b-aa62-12b49866ac6bHung Bui<p>Hi Rastislav,&nbsp;</p> <p>The nRF52840 is not designed to be programmed via the USB D+ and D- pin. It has to be flashed using the SWD interface as described in the specification.&nbsp;<br />However, it&#39;s possible to make a DFU bootloader that can receive the image via the USB either as USB interface or a virtual COMport interface and then replace the original application with the new image.&nbsp;<br />This is how we do it with the nRF52840 dongle. Take a look here:&nbsp;<a href="https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/boards/nordic/nrf52840dongle/doc/index.html">https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/boards/nordic/nrf52840dongle/doc/index.html</a></p> <p>Note that this solution is better suite for flashing final image as it doesn&#39;t provide any way of debugging and it take longer time to do flashing compare to the traditional way of flashing via a programmer.&nbsp;</p><div style="clear:both;"></div>