2021-06-10, 03:48 PM
I had the same issue in conjuction with a Raspi 4 and the pican-m HAT, which has a rs422 interface to send and receive NMEA0183 data.
After every boot the command
ls -l /dev/ttyS0
only showed read permssions for user and group: crw-r--r--
when I modified this using
sudo chmod 666 /dev/ttyS0
rights temporarily changed to crw-rw-rw-
and the signal-k server connected to the interface.
The solution to this problem is to modify the file /boot/cmdline.txt.
In my installation it was this command line
I simply removed the console-part:
and rebooted. After this everything was fine without changing the access rights manualy.
Michael
incomplete
After every boot the command
ls -l /dev/ttyS0
only showed read permssions for user and group: crw-r--r--
when I modified this using
sudo chmod 666 /dev/ttyS0
rights temporarily changed to crw-rw-rw-
and the signal-k server connected to the interface.
The solution to this problem is to modify the file /boot/cmdline.txt.
In my installation it was this command line
Code:
console=tty1 root=PARTUUID=320441f2-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles console=serial0,115200I simply removed the console-part:
Code:
console=tty1 root=PARTUUID=320441f2-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consolesand rebooted. After this everything was fine without changing the access rights manualy.
Michael
incomplete