CDC UART nRF52832 Virtual Box Linux Guest not working

[darioclock]

Hello,

I have been trying to communicate via UART with the Nordic nRF52832 DK (10040) in a Linux (Fedora 26) Guest on Virtual Box. The guest is Windows 7.

The JLink drivers seem to work properly for device programming. However, when I connect a serial terminal to ttyACM0 no data is received despite being able to open the port. I tried using minicom and gtkterm with equivalent result.

If I run the same program in the Windows guest and listen with Putty I get the expected data.

JLink Linux = V620c JLink Win = V620d

Any idea on I could tackle the problem and have the UART working in the VM?

[kl-cruz]

Possible issues:

-> HW flow control, baudrate (check configuration)

-> Modem catch ttyACM on Linux. (maybe send some dmesg logs to investigate). Modem-manager can catch ttyACM in-out transmission. (stackoverflow.com/.../modem-manager-and-ttyacm-in-use)

In addition, picocom is also small and cute terminal.

If You will have still problems maybe try to use arch or manjaro linux. AUR repository has good support for nRF and Segger tools: aurabindo.in/.../

Of course don't forget about udev rules!

[Sigurd]

Hi,

Have you granted serial port access permissions to your user? To do this, run the following command:

sudo usermod -a -G dialout <username>

[darioclock]

-> The udev rules were installed as specified by the readme in the JLink folder (using ATTR, not SYSFS)

-> Port configuration seems correct, I use the same in Putty.

-> I removed modemmanager just to be sure and the problem persists.

Here is the dmesg output http://m.uploadedit.com/bbtc/1507047062583.txt

[darioclock]

yes, I'm in the dialout group

[darioclock]

I found out that the problem is related to the EHCI Controller (USB2.0) of virtual box. Using either USB 3.0 or 1.1 controllers allows me to send and receive data to/from the terminal.

I had to run the board through a power cycle to have the in stream from keyboard working again.

Also, apparently, the physical USB port that the board is connected to is also important. Connecting to a port expander (such as the ones that come with SD card readers etc in prefab desktops) won't work for me, I need to use an USB port directly located on the motherboard.