Integrating Buttonless DFU: with extra custom 128bit UUID (SDK 12.x)

[Tanasis!]

Assuming SDK 12.x

For those people that want to integrate the Buttonless DFU service to their app, which uses already one custom base 128bit UUID, please make sure to:

1. Edit softdevice_handler.c (located at components/softdevice/common/softdevice_handler/):

   uint32_t softdevice_enable_get_default_config(uint8_t central_links_count,
                                             uint8_t periph_links_count,
                                             ble_enable_params_t * p_ble_enable_params)
   {
       memset(p_ble_enable_params, 0, sizeof(ble_enable_params_t));
       p_ble_enable_params->common_enable_params.vs_uuid_count   = 2; // HERE MAKE THIS 2!!!
       p_ble_enable_params->gatts_enable_params.attr_tab_size    = SOFTDEVICE_GATTS_ATTR_TAB_SIZE;
       p_ble_enable_params->gatts_enable_params.service_changed  = SOFTDEVICE_GATTS_SRV_CHANGED;
       p_ble_enable_params->gap_enable_params.periph_conn_count  = periph_links_count;
       p_ble_enable_params->gap_enable_params.central_conn_count = central_links_count;
       if (p_ble_enable_params->gap_enable_params.central_conn_count != 0)
       {
           p_ble_enable_params->gap_enable_params.central_sec_count  = SOFTDEVICE_CENTRAL_SEC_COUNT;
       }
   
       return NRF_SUCCESS;
   }
   

Credits to mosi.

2. Making the above change, means you have to adjust RAM ORIGIN in your linker script as well, e.g. the ble_app_gcc_nrf51.ld. Probably it will start 16 bytes (+ 0x10) after the current value. (Hint: If you run your app with NRF_LOG on, the Softdevice will report the correct value you need to use)

3. If applicable: There is bug in the buttonless DFU example. Adjust the nrf_dfu_flash_buttonless.c:

   uint32_t nrf_dfu_flash_init(bool sd_enabled)
   {
     fs_fake_init(); // IMPORTANT! ADD THIS! WAS BUG IN THE EXAMPLE!
     m_flags = FLASH_FLAG_SD_ENABLED;
     return NRF_SUCCESS;
   }
   

Otherwise you will get flash operation errors.

4. Don't forget to patch BLE DFU Service ble_dfu.c

   static uint32_t rx_char_add(ble_dfu_t * p_dfu, const ble_dfu_init_t * p_dfu_init)
   {
     ...
     char_md.char_props.write  = 1; // ADD THIS! IT IS MISSING!
     ...
   }
   

That's it! :) Enjoy!

[Nguyen Hoan Hoang]

It's a lot simpler. You don't need to add a custom dfu service for buttonless DFU. Just add these 2 functions snippet from the EHAL library to your code. Call the function BlePeriphAppEnterDfu(). It will automatically switch to DFU.

void BlePeriphAppDfuCallback(fs_evt_t const * const evt, fs_ret_t result)
{
    if (result == FS_SUCCESS)
    {
        NVIC_SystemReset();
    }
}

void BlePeriphAppEnterDfu()
{
    uint32_t err_code = nrf_dfu_flash_init(true);

    nrf_dfu_settings_init();

    s_dfu_settings.enter_buttonless_dfu = true;

    err_code = nrf_dfu_settings_write(BlePeriphAppDfuCallback);

    if (err_code != NRF_SUCCESS)
    {
    }
}

[Arepa]

Hi Nguyen,

Are necessay any #include to use that snippet code? or Any aditional step to switch to DFU bootloader from the applicacion (e.g ble_app_uart example)

Thanks

[Nguyen Hoan Hoang]

you need to #include "nrf_dfu_settings.h"

[Sanjay Shreedharan]

Steps 1, 2 and 3 need not be followed. Only Step 4 as such is enough to get the custom DFU application working. If anyone is facing any issues, I would be happy to help!