Connectiviy problem

[Rick Walsh]

Mario,

We're getting close to the solution now. And it is worth persisting.

On 24 April 2014 05:46, Robert C. Helling <helling at atdotde.de> wrote:
>
> On 23 Apr 2014, at 21:09, Mario Pilz <mariopilz at gmx.net> wrote:
>
> Mario,
>
>> 2. Then I run: sudo tail -f /var/log/syslog
>> Output: usb 2-1.1: FTDI USB Serial Device converter now attached to ttyUSB0
>>
>
> OK, then /dev/ttyUSB0 is your device (capitalisation is important).
>
> Please do
>
> sudo chmod a+rw /dev/ttyUSB0
>
> after connecting the cable and the D4. If that solves the problem, then it is really the permissions problem that we are all trying to address. But it might be something else. Unfortunatly, this solution is only good until the next reboot (or possibly disconnect of the cable, I am not sure).
>

Your issue may just be capitalization. Double check that you are
specifying /dev/ttyUSB0 in subsurface.

In order to establish permissions, there are two different ways:
1) Add yourself to the group that has 'write' access to the device
(this is recommended)
2) Change the permissions of the device (like Robert's suggestion
above, which gives all users write access to the device)

The first method is preferable because it is permanent. The device
files /dev/ttyUSB0 is created when you plug in the cable, so I think
changing permissions will only work until the next time you plug in
the cable or reboot. Giving non-privileged users write access to a
device is also not recommended, but if you're the only user, and the
device is a dive-computer, it probably isn't an issue in itself.

On most systems, the group is dialout, but some may be special. To
confirm what the required group is, after plugging in the cable (the
device file is created when you plug in the cable) enter on the
command line (as suggested by Robert before):

ls -l /dev/ttyUSB0

The output should look something like (on my system, Febora 20)
crw-rw----. 1 root dialout 188, 0 Apr 24 07:18 /dev/ttyUSB0

This shows that the owner of the device is 'root', and its group is
'dialout'. This means you need to be a member of that group to have
write access. Double check you are with the command:

groups

This will list all groups you belong to, for me:
rick wheel dialout pkg-build

If the group that /dev/ttyUSB0 belongs to isn't listed there, add
yourself to it.

sudo usermod -a -G dialout mario

Log out and the back in again before trying to download from your dive computer.

Cheers,

Rick