First packets in a DFU communication

[megawarpx]

Hi again, by sniffing the communication channel I see that AuTerm sends some packets before starting to transmit the firmware. Could you give me some information about the content of those packets and the sequence of operations to implement to send the firmware?

[thedjnK]

Not sure what you mean, it sends the commands as per https://docs.zephyrproject.org/latest/services/device_mgmt/smp_groups/smp_group_1.html

[megawarpx]

I'm sorry, I was at an early stage and did not realize there were (for some reason) problems. There were a few (unsuccessful) retries at the beginning before the actual firmware trasmission started. In the end I was able to decode the packets.

I needed this sequence, which was not clear to me at first:
Data to send -> CBOR encoding -> SMP frame creation -> BASE64 encoding -> (possible fragmentation) -> Add header, trailer (+ CRC, possibly) -> Transmission via UART

Thank you