Using DFU service without bootloader

[Aymen Rejeb]

Hi all,

I have an STM32 connected to an nrf51822 via uart, and I want to do a firmware update of the stm via ble.

Therefore, I would like to take advantage of the Master Control Panel as a central to send the .bin file to the STM32 using the dfu service.

However, I don't want to use a bootloader, I just want to use the dfu service to download the .bin file and then re-send the received image via the uart!
Does anyone know if it is possible to do this way?

Many thanks in advance.

[Hung Bui]

Hi Ayman,

What do you mean by you "don't want to use a bootloader" ? What you want to achieve of receiving a file from Master Control Panel via DFU service is pretty much the main functionality of the bootloader.

How can you receive the file without writing a very similar code to the bootloader code.

Actually what you want to do is even more complicated than the bootloader code, the extra part is to forward what you receive to UART instead of storing them to flash.

I don't think we have a ready made example for this. What I can suggest you is, if you don't want to enter bootloader, you can copy the code we used in the bootloader for receiving image from the DFU master, then you can either store them in the flash (same as the bootloader does) and then send them to the STM after you finished receiving. Or you can forward the image when you receive every packet.

You can also refer to our serial bootloader to implement your code on the STM as they have pretty similar MCUs.

[Aymen Rejeb]

Hi Hung,

Thank you for the swift and clear response.

As you mentioned above, using the dfu bootlooder is much more efficient and straightforward solution! I think it would be better to just modify the existing bootloader in a way to froward the received packet over the UART to the STM.

Many thanks.