dario111cro:
Don't bother yourself when it's already done for you:
Google Code Archive - Long-term storage for Google Code Project Hosting.
Could you please explain how phpSerial solves the problem any better than the dio extension does?
The phpSerial::deviceOpen() method uses fopen() to open the device (svn/trunk/phpSerial.php:177), and fopen() returns a resource. As colbec's most recent post clearly shows, $_SESSION can't be used to make the resource returned by fopen() persist across PHP script invocations.