I'm trying to implement a DFU solution for an STM32F411 device and am having a tough time figuring out what the best solution is. Unfortunately the STM32 is the PMIC for the host that needs to do the DFU so bootloader is not an option without hardware modification and even then I can't get the device to enter USB mode for some reason (another issue).
Ideally we'd like to use the existing USB connection to do the update in application but there are no samples available for the F411 and when I tried copying one of the existing DFU samples I started running into issues with the code using defines not available for the F411. We have an I2C interface available between the host and STM as well so perhaps that's a better option?
I'm hoping someone can comment on what the best direction to go is in terms of development time/complexity or offer any other better alternatives.