Timeline for Error on changing permissions in serial port
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 8, 2018 at 11:37 | comment | added | Sergio Prieto | I switched the serial ports ttyAMA0 and ttyS0 to get a better control of the Baudrate, that is the reason why the ttyAMA0 port has crw--w---- | |
| Jul 8, 2018 at 11:14 | comment | added | lenik | @SergioPrieto following your earlier message: "I have these permissions on ttyAMA0 port: crw--w----" -- this is strange, permissions on /dev/ttyAMA0 should be crw-rw---- -- owner and group can read and write. | |
| Jul 8, 2018 at 11:12 | comment | added | lenik | @SergioPrieto once you have killed the process, you don't have to change the permissions, you should be able to access /dev/ttyAMA0 easily, as long as you are in tty group. If you have just added yourself to this group, you'll need to logout/login again for things to work. | |
| Jul 8, 2018 at 11:00 | comment | added | Sergio Prieto | I used this command to kill the process:sudo systemctl stop [email protected], now I am able to change the permissions without any automatic change in permissions each minute. The problem now is that each time I reboot the Raspberry the permissions change to the default configuration. | |
| Jul 8, 2018 at 8:48 | comment | added | lenik | @SergioPrieto well, likely you have terminal sessions waiting for users on those terminals. try to killall agetty, but be careful, it might kill something useful =) | |
| Jul 8, 2018 at 8:15 | comment | added | Sergio Prieto | the output of the lsof command is the followingagetty 800 root 0u CHR 204,64 0t0 1157 /dev/ttyAMA0 agetty 800 root 1u CHR 204,64 0t0 1157 /dev/ttyAMA0 agetty 800 root 2u CHR 204,64 0t0 1157 /dev/ttyAMA0 | |
| Jul 8, 2018 at 8:11 | comment | added | lenik | @SergioPrieto try lsof /dev/ttyAMA0 to find out if someone else's using the port? | |
| Jul 8, 2018 at 8:09 | comment | added | Sergio Prieto | I have tried it and the output is the following:The user pi' is already a member of tty'. Moreover, when I execute a script to access the /dev/ttyAMA0 the result is: Permission denied: '/dev/ttyAMA0'. I have these permissions on ttyAMA0 port: crw--w---- 1 root tty 204, 64 Jul 5 11:15 ttyAMA0 | |
| Jul 8, 2018 at 7:52 | history | answered | lenik | CC BY-SA 4.0 |