# Outboard DFU using MCUBoot - NRF52840

**URL:** <https://discuss.blues.com/t/outboard-dfu-using-mcuboot-nrf52840/1978>\
**Category:** Firmware\
**Created:** [February 23, 2024, 5:06pm UTC](https://discuss.blues.com/t/outboard-dfu-using-mcuboot-nrf52840/1978 "2024-02-23T17:06:09Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![kdl](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kdl](https://discuss.blues.com/u/kdl)\
**Post date:** [February 23, 2024, 5:06pm UTC](https://discuss.blues.com/t/outboard-dfu-using-mcuboot-nrf52840/1978/1 "2024-02-23T17:06:10Z")

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Hi @zfields ,

I am wondering if there is someone familiar with outboard firmware updates using MCUBoot. I am using a NRF52840 Soc and am implementing the example found here [note-outboard-dfu/nrf52840/blinky/ncs/README.md at main · blues/note-outboard-dfu · GitHub](https://github.com/blues/note-outboard-dfu/blob/main/nrf52840/blinky/ncs/README.md)

The problem I have is my board immediately enters MCUBoot when I am using GPIO0.10 as the DFUButton similar to the example and once entered into MCUBoot, it never leaves.

There isn’t much for information specific to MCUBoot on dev.blues so would like to know if anyone at Blues is an expert on it.

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**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\
**Post date:** [February 23, 2024, 6:38pm UTC](https://discuss.blues.com/t/outboard-dfu-using-mcuboot-nrf52840/1978/2 "2024-02-23T18:38:14Z")

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Hi kdl, welcome back to the forum!

This is a tough one. I need to jump back into that code base to familiarize myself with what you’re seeing.

Can you provide us with some more information about your setup? Which Notecard, Notecarrier, version of Notecard firmware, version of `note-arduino` or `note-c` or `note-python` you are using? Which nRF52840 are you using? I have a couple nRF52840s, maybe I have the same one as you.

Finally, are you able to send a photograph of your hardware setup, and any code related to managing the button press?

Best,  
Zak

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**Author:** ![kdl](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kdl](https://discuss.blues.com/u/kdl)\
**Post date:** [February 29, 2024, 4:43pm UTC](https://discuss.blues.com/t/outboard-dfu-using-mcuboot-nrf52840/1978/3 "2024-02-29T16:43:21Z")

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So sorry! I had my notifications off so did not realize you responded. I am using a custom board that I designed with a aQFN package for the nrf52840. While I was trying to battle through the issue, I realized that the nrf52840 will allow you to perform a “wait for serial” to initiate a DFU update upon a reset. So I was able to eliminate the need for a DFUButton which means AUX3 connection to the Notecard is not actually required 🙂

I won’t upload pictures at this time as the hardware would require significant description to explain it and not as “pretty” as I would like it at this point.