Unable to burn custom firmware.

RE: Unable to burn custom firmware.

bjorn-spockeli — Mon, 30 Oct 2017 14:49:42 GMT

@govardhanan (Gova): Yes, you are correct.

RE: Unable to burn custom firmware.

Otavio Borges — Thu, 26 Oct 2017 17:45:07 GMT

I'm not familiar with the DFU bootloader on Thingy. But, basing on nrf52-DK DFU bootloader, the only way to upload your custom firmware without an ARM programmer is either if Thingy bootloader does not have key-pair validation or you find the original private key from nordic. Search a little deeper if nordic provides any documentation in that matter. Remember that once you reflash the device with another bootloader you won't need to use the programmer unless you want to recover the device (rewrite the bootloader), so perhaps you could borrow one DK board (a Segger J-Link would do the trick as well).

RE: Unable to burn custom firmware.

Gova — Thu, 26 Oct 2017 17:27:02 GMT

I have already been advised to burn the bootloader first in my previous question whose URL is

how-to-flash-bootloader-to-thingy-52

If you can see the comments, I was told to hold down the button and bring the thingy to DFU mode and then straight away burn the firmware. But now I understood that that will not work and I need a nRF DK to program the bootloader. Please confirm if my understanding is correct.

RE: Unable to burn custom firmware.

Otavio Borges — Thu, 26 Oct 2017 12:23:28 GMT

You'll need something with an ARM programmer, like nRF52-DK, to replace the factory bootloader. You can use devzone.nordicsemi.com/.../ as guideline.

RE: Unable to burn custom firmware.

bjorn-spockeli — Thu, 26 Oct 2017 11:22:43 GMT

You do not have the private key which corresponds to the public key in the factory programmed bootloader on the Thingy so you will not be able to update the application via OTA DFU.

The Over-the-air device firmware update section in the Thingy User Guide describes how you update the application that is made by Nordic Semiconductor through the Thingy app. It does not cover how to update your own application, which requires you to compile your own bootloader with your public key and flash the bootloader using a programmer and a cable.

You should look at the nRF5 SDK documentation on the bootloader, see this page on Infocenter.