Pass a USB device to node-RED docker - permission denied

[Struck]

Hi

 

I am trying to connect an arduino pro micro via usb serial to the node-RED docker container, but i have no luck.

 

I have made a minimalistic arduino code that just outputs a number on the serial. 

When i connect the arduino to the unraid server, i can from the console use the screen command, to see the output on the serial port (/dev/ttyACM0)

 

I have then tried to map this device into the node-red docker by adding a new device into the docker, with the  value field to "/dev/ttyACM0"

 

Wheni then try to run node-RED with the serial port plugin, and try to set the serial port to /dev/ttyACM0 it tells me 

"serial port /dev/ttyACM0 error: Error: Error: Permission denied, cannot open /dev/ttyACM0"

I have also tried with the privileged mode.

Any ideas?

 

As bonus info, I have successfully connected to the serial port with a VM running windows as a test.

[saarg]

You probably need to change the permission on the host side so that the user in the container running the software have the rights to read/write to the device. 

If you want to be sure, do a chmod 777 /dev/ttyACM0 and restart the container. 

Edited January 31, 2019 by saarg

[Struck]

Ok, i tried to do chmod 777 ttyACM0, and it worked.

But as far as i know, the permission will reset when restarted, right?

How do i make it persistent?

root@Hotbox:/dev# ls -l ttyACM0
crw-rw---- 1 root dialout 166, 0 Feb  1 00:45 ttyACM0
root@Hotbox:/dev# chmod 777 ttyACM0
root@Hotbox:/dev# ls -l ttyACM0
crwxrwxrwx 1 root dialout 166, 0 Feb  1 00:45 ttyACM0

 

[saarg]

10 hours ago, Struck said:

Ok, i tried to do chmod 777 ttyACM0, and it worked.

But as far as i know, the permission will reset when restarted, right?

How do i make it persistent?

root@Hotbox:/dev# ls -l ttyACM0
crw-rw---- 1 root dialout 166, 0 Feb  1 00:45 ttyACM0
root@Hotbox:/dev# chmod 777 ttyACM0
root@Hotbox:/dev# ls -l ttyACM0
crwxrwxrwx 1 root dialout 166, 0 Feb  1 00:45 ttyACM0

 

 

You just add it to your go file in /boot/config/go.

[kuhnino]

OK, works for me as well by executing the "chmod 777 ttyUSB0" command. Tx for that hint.

Anyhow, how to edit the "/boot/config/go." file ???? May I missed that info somehwere so even a link to educate myself would be helpful

[itimpi]

3 minutes ago, kuhnino said:

Anyhow, how to edit the "/boot/config/go." file ????

You could install the Config File editor plugin.

[kuhnino]

As always, if u know how, it´s soooo easy.

TX