nRF5340DK VCOM only works with putty

[ubat]

Hey guys,

an issue I was postponing but need to solve for an upcoming management demonstration: I can only connect to the nRF5340DK VCOM with putty.

Using Hterm or the Matlab serial port functionality, which is what I need for the demo, will shut down the Jlink cpu. LED5 will turn off, and the Jlink CDC UART port disappears from the device manager.

I tried DTR/RTS pins on and off, to no avail. This solved the problem here nRF52 DK - USB CDC ACM Example not working with HTerm/Qt - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com) e.g., which is similar I guess.

The Jlink cpu seems to reset upon Hterm or Matlab serial connecting. The nRF5340 is still up and going, as indicated by LEDs signaling new received packets.

Any idea?

Thank you,

Uli

[Øyvind]

Hello Uli, 

Can you provide more information on what version of the nRF5340DK you are running and with what application? I will try to replicate here. That said, the JLink CPU should not be affected when connecting via Serial, Do you see 2 serial ports from the device?

Kind regards,
Øyvind

[ubat]

Thank you - I will gladly go forward and try to solve this!

Usually flashing will be like this:

west flash -d d:\xyz\build --skip-rebuild -r nrfjprog --dev-id 1050083097

-- west flash: using runner nrfjprog

-- runners.nrfjprog: Flashing file: d:\xyz\build\zephyr\zephyr.hex

Parsing image file.

Verifying programming.

Verified OK.

Applying pin reset.

-- runners.nrfjprog: Board with serial number 1050083097 flashed successfully.

In the failure mode, the board is still listed in Visual Studio and I can klick on Program, then the following happens:

	Flashing build to undefined
	west flash -d d:\xyz\build --skip-rebuild -r nrfjprog --dev-id 1050083097
	
	-- west flash: using runner nrfjprog
	-- runners.nrfjprog: Flashing file: d:\xyz\build\zephyr\zephyr.hex
	ERROR: Unable to connect to a debugger.
	ERROR: JLinkARM DLL reported an error. Try again. If error condition
	ERROR: persists, run the same command again with argument --log, contact Nordic
	ERROR: Semiconductor and provide the generated log.log file to them.
	NOTE: For additional output, try running again with logging enabled (--log).
	NOTE: Any generated log error messages will be displayed.
	FATAL ERROR: command exited with status 33: nrfjprog --program 'd:\xyz\build\zephyr\zephyr.hex' --sectorerase --verify -f NRF53 --snr 1050083097 --coprocessor CP_NETWORK
	
	 *  The terminal process terminated with exit code: 33. 
 *  Terminal will be reused by tasks, press any key to close it. 

And while I would love to run with --log and provide the log.log, I'm sorry but I was unable to modify this command, or to call it manually from the command line - 'west' is not in the path, and the 'west.exe' I could find is not suitable.

[Øyvind]

ubat said:

And while I would love to run with --log and provide the log.log, I'm sorry but I was unable to modify this command, or to call it manually from the command line - 'west' is not in the path, and the 'west.exe' I could find is not suitable.

How do you build this project?

ubat said:

FATAL ERROR: command exited with status 33: nrfjprog --program 'd:\xyz\build\zephyr\zephyr.hex' --sectorerase --verify -f NRF53 --snr 1050083097 --coprocessor CP_NETWORK

This error is a generic Segger error, that can mean many different things depending on context. We will need to see the logs. 

You should be able to call nrfjprog -r -f NRF53 --log from the command prompt of your windows computer.

Kind regards,
Øyvind