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:

[Matt]

Can you try baud rate 57600?

[Alice]

I have tried other baud rate, for example 9600,19200,38400,57600 and so on, but it also couldn't update the firmware. Could you make it if disable flow control?

[bjorn-spockeli]

@alice: If you're not using flow control the you should use a low baudrate, e.g. 9600 to avoid overflowing the RX buffer of the nRF52.

[Alice]

@Bjørn Spockeli：I have used 9600 baud rate, but it also couldn't update the firmware. Have you met the problem?

[bjorn-spockeli]

Yes, I am seeing the same issue. Are you able to use 9600 with flow control enabled?