Need information of packet format and specifications for the various stages of the DFU

[srijita_thakur]

Hi,
We are using nrf51822 in our device and Device firmware update is implemented in it and we are being able to do the device firmware upgrade by using nrfConnect app.
Now the requirement is to be able to do the OTA DFU using nodejs code and using noble(not via serial). We wanted to know the packet specifications for the various stages of the DFU since its part of the SDK 
1. Reading firmware version
2. Jumping to bootloader mode
3. Control init 
3. Data write

Thanks

[Edvin]

I am not familiar with Noble, but do you want to use BLE to transfer the image?

If so, you can use nrfutil, which is a python script. It is open source found here. Perhaps you should try to use nrfutil to perform a DFU, to see how it works. It requires a DK or dongle connected to the computer. You can see the description on how to test it here.

BR,

Edvin

[srijita_thakur]

Yes we want to do this via BLE and i have also checked out nrfutil previously, bt we dont want any dongle to be involved, rather there should be a nodejs code running inside a hub which should be able to do the DFU

[srijita_thakur]

we want to use the board BLE peripheral , through which we want to do the transfer of packets and the command format need not be specific to noble. Can you please share the commands sequence which need to be followed to initiate the DFU and the command payload??

Also to add to this, on end device, the nrf SDK supplied bootloader is used except that service/char UUID is our own

[Edvin]

Ok, so you want to know the protocol to upload the new firmware, then.

It is described briefly in the DFU description on Infocenter. There are some other sites around that section on infocenter that are useful as well. Please use the content tree on the left.

The sequence chart should be quite useful. Other than that, we don't have much documentation on nrfutil, but the source code is available, as I linked in the preivous reply. You can use this to check how the application flow is implemented.

Best regards,

Edvin