SDK 12.1.0 DFU service fails to perform firmware upgrade

[RahulR]

I performed below mentioned steps:

1. Downloaded SDK 12.1.0
2. Soft Device s130_nrf51_2.0.1_softdevice.hex
3. Built secure boot-loader with new public key
4. Built project ble_app_hrs for pca10028 on Keil compiler with DFU service added.
5. Downloaded Soft device and Boot-loader hex files through nrfConnect Programmer
6. Generated DFU .zip package with below command line arguments: nrfutil.exe pkg generate --application application.hex --application-version 0xFFFFFFFF --hw-version 51 --sd-req 0x87 --key-file private.key %file_name%.zip
7. Able to download DFU .zip package through nrfConnect mobile App
8. .
9. Able to connect to device successfully with DFU Service and DFU button visible .
10. 
11. On attempting to perform DFU with same .zip file, App is stuck at "Starting Boot-loader" message and does not proceed further
12. 
13. DFU is not done successfully.

Please help me resolve this issue.

Thanks,

Rahul

[RahulR]

One think I observed is at the time addition of DFU service, I did not see event handler defined for DFU.

Is it available or do I have write it on my own?

[Vidar Berg]

Hello,

Did you try with the Buttonless DFU Template Application first before you started with the heart rate example? Note that it's not sufficient to just add the BLE DFU service, you also need to include nrf_dfu_flash_buttonless.c and nrf_dfu_settings.c as in the template example.

Also, the DFU control point characteristic lacks the required write permission as noted in the SDK 12.3.0 release notes:

To switch to DFU mode, you must write to the DFU control point.
However, this characteristic is set as read only. Add the following

code line to enable the write property: char_md.char_props.write = 1;
For details, see https://devzone.nordicsemi.com/question/93414/sdk12-ble_app_buttonless_dfu/#95079 

[RahulR]

I built Buttonless DFU Template Application with the change as you suggested

char_md.char_props.write = 1; inside rx_char_add() API (Please correct me if wrong)

Below is the behavior observed:

1. Application is broadcasting "Nordic_Template"
2. On initiating DFU, application starts boot-loader.
3. Connection is established with boot-loader
4. Boot-loader is broadcasting "DFUTARG"
5. On initiating DFU, App keeps messaging "Initializing..."
6. Firmware upgrade does not happen
7. In the background nrfConnect is still connecting with "Nordic_template"
8. I restarted nrfConnect App.
9. After that I was able to upgrade Application successfully.

How do I fix this issue?

Thanks,

Rahul