I'm working with the Nucleo F767ZIT (QFN-144) to test the F7's abilities, and currently I'm struggling with the USB DFU capability. I've read a few posts about issues getting the DFU working due to the F7 requiring option bytes to be set, but none of them have come across my issues. I'm testing the Nucleo on both macOS 10.13 (High Sierra) and Windows 10 trying to get DFU flashing to work.
The Nucleo doesn't come with a HSE, so I installed the recommended 8 MHz crystal, 4.3 pF caps, and de/soldered the necessary jumpers. I have tested bidirectional USB FS communication without a problem, and I have intentionally invoked the CSS NMI callback to ensure the HSE is running, which it is.
My first issue is trying DFU with the STM32 Cube Programmer in Windows. I first connected to the Nucleo using the STLink and checked that the option bytes were correct to allow DFU. I then held Boot0 high, reset the MCU, and it entered the DFU boot loader. Device manager reported "STM Device in DFU Mode." I then went to the USB section in Cube Programmer and it couldn't find the MCU even after clicking refresh and restarting the program.
I then went to DfuSe v3.0.5 and that could connect to the MCU, erase and flash no problem. I have attached a screen shot of the option bytes seen in STLink Utility. Interestingly, nDBOOT shows up on STLink Utility but not in Cube Programmer.
To fulfill cross-OS support, I attempted DFU with Cube Programmer in macOS, but that didn't work either. It found a USB device but it had a strange serial number and wouldn't connect to it, giving corruption error messages and unknown device.
I also have a Nucleo F447ZE that I tested. That one works in Cube Programmer in macOS but not Windows.
So to break it down:
- Nucleo F767 works in Windows 10 DfuSe v3.0.5
- Does not work in Windows 10 Cube Programmer. USB device not even found.
- Does not work in macOS Cube Programmer. USB device found, but with weird serial number.
- nDBOOT option byte doesn't show up in Cube Programmer.
I would love to get this solved, so if anybody has thoughts on what would be causing this behavior, I appreciate any input. Thank you.