SDK 13.0 couldn't do DFU using UART when disable flow control

[Alice]

Hi,

I'm using nRF52832 and nRF52840 to work with MCU, then we should do the firmware update by the uart. I have compiled the bootloader_secure_serial project in the SDK 13.0 and then program it to the DK board, I run the command in the command line:

nrfutil dfu serial -pkg Blue5_test.zip -p COM5 -fc 1 -b 115200

It's OK. There is no flow control on my board, so I disable it in the serial_dfu_transport_init() function:

uart_config.hwfc               = NRF_UART_HWFC_DISABLED;

Then run the command:

nrfutil dfu serial -pkg Blue5_test.zip -p COM5 -fc 0 -b 115200

But it couldn't update the firmware and get the error as follow:

[bjorn-spockeli]

Hi Alice, that is an interesting observation, which may indicate that the interface MCU(which runs the JLINK OB on the DK) might have something to do with the issue since its acts as a UART-> Virtual Com port bridge.

I am afraid that we do not have any examples for the host MCU side when it comes to serial DFU. You will have to refer to the Serial Bootloaders transport layer documentation to see the packet format, here is the link to the relevant page.