MOD-ZIGBEE-UEXT is low cost UEXT module which can act as Zigbee coordinator and to talk to all Zigbee devices nearby.
This GitHub project https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/iMX233/MOD-ZIGBEE add Zigbee interface to iMX233-OLinuXino-MAXI and allow MOD-ZIGBEE-PIR sensors to be scanned and if movement detected to log it into file.
After downloading and building add the zigbee.php to your web server directory.
olimex 
Nov 02, 2012 @ 23:17:53
Does MOD-ZIGBEE-UEXT have FCC approval?
Nov 02, 2012 @ 23:22:20
no, we didn’t run such approvals, but this is copy of Microchip’s ZIgbee module which have all these approvals, so I’m 100% sure we comply just don’t want to pay $$$ for something I already know 🙂