Virtual /dev/ttyACMx COM port not found on macOS or Linux

RE: Virtual /dev/ttyACMx COM port not found on macOS or Linux

Mttrinh — Fri, 06 Dec 2019 14:56:49 GMT

Hi,

Glad that it worked out for you. And regarding the documentation, I will report this internally.

Sorry for the inconvenience.

RE: Virtual /dev/ttyACMx COM port not found on macOS or Linux

bfriedk1 — Wed, 04 Dec 2019 22:29:06 GMT

Hello -

Thank you for sticking with me. I was able to install and launch the J-Link Configurator app on both macOS and Linux. As you suggested, the VCOM post was enabled, so I disabled the port. That seems to have resolved the issue. The call to app_usbd_cdc_acm_write() no longer fails and I see the output in the serial console. I also now see /dev/ttyACM0 on Linux.

I would suggest updating the example app documentation to note that the virtual COM port enumerates as "usbmodemX" on macOS. Also it might help others to note that the SEGGER VCOM port needs to be disabled in order for this example app to work properly.

Anyway, thanks again for your help.

Regards,

Brian

RE: Virtual /dev/ttyACMx COM port not found on macOS or Linux

Mttrinh — Wed, 04 Dec 2019 12:22:51 GMT

You can check if the SEGGER VCOM is enabled via the JLink Configurator. Use the link in my previous answer, under "Via J-Link Configurator" you can see how the VCOM is enabled/disabled.

No, Rev 1.1.1 isn't a PDK. On MacOX the port should come up as usbmodem while on Linux it should come up as ACMx. It is weird that it doesn't show up as ACMx on Linux though.

Can you try disable the VCOM and try again? If possible can you try with another board too?

RE: Virtual /dev/ttyACMx COM port not found on macOS or Linux

bfriedk1 — Wed, 27 Nov 2019 23:34:26 GMT

Hello -

Thank you for the follow-up. I am not sure how to know if the board is connected to SEGGER VCOM. This is what I see when I run JLinkExe on macOS:

SEGGER J-Link Commander V6.22g (Compiled Jan 17 2018 16:45:05)
DLL version V6.22g, compiled Jan 17 2018 16:44:56

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan  7 2019 14:07:15
Hardware version: V1.00
S/N: 683610167
VTref = 3.300V

This is what I get when I list the virtual com ports:

$ ls /dev/cu*
/dev/cu.Bluetooth-Incoming-Port /dev/cu.usbmodem14111 /dev/cu.usbmodem14121

I don't believe I am running a preview DK. My nRF52840-DK board box sticker shows:

nRF6828

Rev. 1.1.1

2019.26

Lastly, this is what I see in the CLI interface:

My guess is that the error (described above) indicates that the board is connected over serial but not through the virtual com port. We don't see /dev/ttyACMx when listing the ports on macOS or Linux.

Regards,

Brian

RE: Virtual /dev/ttyACMx COM port not found on macOS or Linux

Mttrinh — Wed, 27 Nov 2019 18:39:15 GMT

Hi,

It is correct that you see the port as usbmodem ports on MacOS. It might be that you are connected to SEGGER VCOM when you see the CLI interface. Can you check if this is the case? What version of the nRF52840-DK board do you have? Do you use a preview DK maybe?