When using nrfutil to upgrade the app for 52840dongle, you can see the data shown in the figure through the USB analyzer. The highlighted one does not quite understand the meaning. A total of 69 bytes.I would like to ask the specific meaning, what should we send here if we make the tool for upgrading the application ourselves?And why is there a suffix of 0xC0 at the end of each piece of data? Not in the official documentation.
Meng. said:Not in the official documentation.
That is not true: DFU serial protocol description, second sentence:
"The transport layer uses the SLIP library for encoding and decoding packets."
Hi Turbo J，thanks for your response.
I found my problem, 0xC0 is the end of the packet.
The transfer is compliant with the SLIP library.
But what does the instruction I highlighted mean?
0x08 = NRF_DFU_OBJECT_WRITE
That (and the following 7 Bytes transaction) is the init packet with the metadata for the update.
Thanks Turbo J.
What does this initial packet with metadata for update consist of?
We want to know how to organize this data.
As Turbo J said, the DFU protocol is described on nrfutil (see the link in his first reply).
Are you refering to the 21 22 23 ... packets? I am not sure, but it looks like generic "USB - set up connection" packets.