How to upgrade firmware using dfu first time?

[abhinav]

HI, I am using sdk 8 and pca10028 dk. I follow following procedure,

• Program the softdevice using nrfgo
• Program the test_bootloader using nrfgo
• Program the application using keil. My problem is that on startup it goes into bootloader mode and start advertising as dfuTest but I want it should go into application and start working with it. Please provide solution on how I should achieve it. Regards , Abhinav.

[Øyvind Karlsen]

Hi,

This is covered by the tutorial on setting up DFU. Please let me know if you have any questions or troubles following this tutorial.

Best regards,

Øyvind

[abhinav]

Hi, Thank you very much for the reply. I have followed all the steps from given link. My dfu works fine but for the first time it doesn't start the application directly it goes into bootloader mode but I want my own application to start initially. So please tell which bootloader file I should use in that case as we already have tested with dual_bank_bootloader and test_bootloader.

[Øyvind Karlsen]

As described in section C. of the common FAQ on DFU:

Buttonless DFU means we start the DFU mode from the application without the need of a physical button. The main technique is to set a flag, could be the retention register GPREGRET, or write to flash, etc. And then jump to bootloader either by a reset or directly branching.

Note that the bootloader is always executed before the application. If there is a valid application and if there is no request for DFU, it will forward interrupt and start the main application. This is the reason why we need to set a retention flag to tell the bootloader to enter DFU mode instead of starting the application.

This means that you have either not got a valid application, or you have set the GPREGRET flag.

[abhinav]

can you please elaborate the method of setting the flag retention register GPREGRET. Since I a'int successful in doing that.

[Øyvind Karlsen]

Have a look at the project ble_app_hrs_s110_with_dfu(this can be found in ..\SDK_8.1\examples\ble_peripheral\ble_app_hrs\pca10028\s110_with_dfu\arm5_no_packs), here you will find the file dfu_app_handler.c. In this file there is a function called bootloader_start, this function shows how to enter bootloader mode. The line err_code = sd_power_gpregret_set(BOOTLOADER_DFU_START); is where we set the GPREGRET flag.

Best regards,

Øyvind