Serial DFU - No ping response after opening COM port

[elva]

Hello. 'm trying to DFU using serial bootloader with my custom board.

I've wired my custom board's nrf52833 pin with a USB2UART board.

• nrf52833 RX Pin: P1.02 -- connected -- USB2UART board Tx pin
• nrf52833 TX Pin: P1.04 -- connected -- USB2UART board Rx pin
• RTS & CTS: Not using
• Baudrate: 115200
• HF: false

When resetting my custom board, I've checked the RTT log like this.

And I've got the nrfutil dfu serial like this.

It returns a "No ping response after opening COM port" msg and is not started.

Any help is appreciated!

Regards.

[elva]

I'd solved this issue by changing sdk_config HWFC configurations. But, after I've changed some application's contents and It revivals again...

I think it has a relation with the Nrfutil serial command's timeout. If I set the timeout value to less than 30, DFU always fails. How can I reduce the timeout and How can I check the communication between my board's bootloader and nrfutil?

[Vidar Berg]

Hello,

It looks like there might be an additional delay when using other third party USB UART bridges: https://devzone.nordicsemi.com/f/nordic-q-a/55803/nrfutil-takes-34-seconds-before-starting-dfu. Have you tried setting the connection delay (--cd) to '0' as suggested there?

Best regards,

Vidar