System Port Permissions

Before using moserial with a serial port, you need to make sure that you actually have permission to read and/or write to the port.

On some systems, you may need to do something like "sudo chmod o+rw /dev/ttyS*" and "sudo chmod o+rw /dev/ttyUSB*" to obtain read/write permissions (for all users) on the serial ports. Unfortunately, this may not be persistent after reboots.

Alternatively, you can see what group the devices belong to, and make your account a member of that group. In Fedora 15, for example, you should add yourself to the "dialout" group.