App not starting after DFU

RE: App not starting after DFU

digitalnyx — Wed, 08 Aug 2018 16:15:07 GMT

Einar,

Thanks for the clue. In the SDK I have, DFU check was:

__WEAK bool nrf_dfu_enter_check(void)
{
    return true;
    
    /*
    if (nrf_gpio_pin_read(BOOTLOADER_BUTTON) == 0)
    {
        return true;
    }

    if (s_dfu_settings.enter_buttonless_dfu == 1)
    {
        s_dfu_settings.enter_buttonless_dfu = 0;
        APP_ERROR_CHECK(nrf_dfu_settings_write(NULL));
        return true;
    }
    return false;
    */
}

Overriding it fixed the issue.

Thanks!

RE: App not starting after DFU

Einar Thorsrud — Wed, 08 Aug 2018 12:18:56 GMT

Hi,

Assuming you have not modified the bootloader, the log string "Application sent bootloader request" is only printed if nrf_dfu_enter_check() returns true, which can happen for two reasons:

the GPIO pin used to force bootloader entry is asserted, or
the enter_buttonless_dfu flag in bootloader settings is set to 1.

Which pin is configured as BOOTLOADER_BUTTON, and what is the state of that pin?