SPI DFU timeout not working

[amarin]

Hi,

I am working on an SPI DFU on my NRF52840 DK using SDK 15.2.0. So far the init packet is able to transfer, however, after I create an object for transferring the firmware image, the dfu timeout automatically goes off and returns to the main loop. I have no idea why it is doing this since shouldn't the timer reset every time a protocol is called? I have tried changing the timeout value, and yet the timer still resets after the create data object protocol. Does anyone have any idea why this occurs?

[amarin]

Update: Stepping into the on_data_obj_write_request() function in my code, I found that an assert error occurs when ASSERT(p_req->callback.write); Does anyone know how to fix this assert error?

[Vidar Berg]

Hello,

The callback is supposed to be provided by the transport layer, which I assume is not happening in your code since the assert is being raised. We don't have a reference implementation for SPI (not official at least), but you can see how we do this in the existing USB and UART transport implementation included in the SDK.

[amarin]

Thank you so much! I see that in the UART implementation that when a write command happens, the callback write is not being written to while in my code it does not do that. I still do not understand the reason why this is true. Can you please just explain what the callback.write does?

[Vidar Berg]

 "callback.write" is a function pointer defined by your DFU transport which the DFU request handler will call after the requested data has been stored to flash. It basically tells the transport when it can free its current data buffer.

 "callback.write" points to nrf_dfu_serial_uart.c::payload_free() in the UART bootloader.

[amarin]

That makes a lot more sense! Thank you so much!