Troubleshooting USB access


It may happen that flashing fails for a number of reasons.

Here we will look at some common issues and possible solutions.

Permission denied

One of the most common issues encountered when trying to flash something for the first time is the good old "Permission denied" error message:

This happens because your system considers accessing serial-port USB devices (such as the ioNode) as a 'privileged operation'.

The "bad" solution to this would be to actually install the Dooba SDK as 'root'. This way you can simply run dflash as root. THIS IS NOT A GOOD OPTION!

The proper way to fix this is to understand what permissions we need and grant them to our user - while this may sound complicated, it actually boils down to just two commands.

First, let's see what group can access the device:

 ~ $ ls -la /dev/ttyUSB0
crw-rw---- 1 root dialout 188, 0 Jun 27 09:44 /dev/ttyUSB0

In most cases, the 'dialout' group will have access to ttyUSB0 (the USB serial port for the ioNode).

Now that we know this, let's simply add our user to the 'dialout' group:

 ~ $ sudo usermod -a -G dialout YOUR_USER_NAME

That's it! Now we just need to log out and log back in to reload our permissions.