I found the source for the SkyChart ERROR Open Serial Port. All SkyChart C programs are hardwired to /dev/ttyUSB0. On Raspberry PI 3 model B, USB is labeled as /dev/ttyACM0. In fact, I imagine the same problem exists with SW6P. Setting the USB port in the GUI has no effect. The C code does not reflect any updated path to any config file. To me, this suggests the root of the problem. Would Anat or Richard care to comment?
If this really is the problem, you can symlink ttyUSB0 to ttyACM0 at the RaspberryPI. I think, this would be the easiest solution.
Log into the raspberry via console (ssh) and enter the following commands:
sudo ln -s /dev/ttyACM0 /dev/ttyUSB0 sudo ln -s /dev/ttyACM1 /dev/ttyUSB1 sudo ln -s /dev/ttyACM2 /dev/ttyUSB2 ...
Now you can use /dev/ttyUSB0 and it automatically uses /dev/ttyACM0.
ls -la /dev/ttyU* #> 0 lrwxrwxrwx 1 root root 9 Mär 5 18:03 /dev/ttyUSB0 -> /dev/tty0
To make this permanent edit the file /etc/rc.local and put the above commands in it. /etc/rc.local is run while the system boots.
nano /etc/rc.local ln -s /dev/ttyACM0 /dev/ttyUSB0 ln -s /dev/ttyACM1 /dev/ttyUSB1 ln -s /dev/ttyACM2 /dev/ttyUSB2
Reboot and check with
ls -la /dev/ttyU*
if the symlinks had been set correct. You should see something like:
#> 0 lrwxrwxrwx 1 root root 9 Mär 5 18:03 /dev/ttyUSB0 -> /dev/ttyACM0
There are also other workarounds for this problem (udev rules) but I think this solutions should work and is easy to achieve.
Please give us feedback if you succeeded.
Edited by apos, 05 March 2018 - 12:25 PM.