I’m using a Lacrosse WS 2310 weather station that connects via RS 232 to my computer. I’ve tried both the 32 bit and 64 bit versions of linux weather-display and encountered the same trouble with no data received on /dev/ttyS0. I have an RS 232 to USB converter and tried it out. It worked either way when running the same MOBO on Windows but not on Linux. In searching I found that you need to check the dialout permissions via the ls - l /dev/ttyS0 or /dev/ttyUSB0 command. Now I had the permissions but still no ttyS0 and an intermittent ttyUSB0. Searching I found that you need to do the following
don@don-P43T-ES3G:~$ ls -l /dev/ttyUSB0
crw-rw---- 1 root dialout 188, 0 Jun 7 10:27 /dev/ttyUSB0
don@don-P43T-ES3G:~$ chmod 777 /dev/ttyUSB0
chmod: changing permissions of ‘/dev/ttyUSB0’: Operation not permitted
don@don-P43T-ES3G:~$ su
Password:
root@don-P43T-ES3G:/home/don# chmod 777 /dev/ttyUSB0
root@don-P43T-ES3G:/home/don# ls -l /dev/ttyUSB0
crwxrwxrwx 1 root dialout 188, 0 Jun 7 10:27 /dev/ttyUSB0
root@don-P43T-ES3G:/home/don# exit
exit
don@don-P43T-ES3G:~$ groups
don adm dialout cdrom sudo dip plugdev lpadmin sambashare
don@don-P43T-ES3G:~$ groups don
don : don adm dialout cdrom sudo dip plugdev lpadmin sambashare
don@don-P43T-ES3G:~$
Dialout shows as existing but the first time I found it was not in my Group nor did it exist as a group. That means you have to create Dialout via newgrp command then you have to add it to your group. If it is not a member of your group you can’t access it properly. Then you use the chmod command to put in full permissions to use dialout properly. While I could never get ttyS0 to work ttyUSB0 works fine. I also noted that the program loads very quickly after setting up the dialout group. You do get some TTY errors on loading until the program and the weather station sync up.