Bjorn at Einhugur has created a bunch of tutorials for projects you can create using Xojo and a Raspberry Pi.
These projects are all free and show you how to hook up a variety of sensors to your Pi and then interface with them using Xojo. Topics include:
- Motion Sensor
- Relay Board
- Flame Sensor
- Humidity and Temperature Sensors
- Infrared Sensor
- Ultrasonic Sensor
These projects make use of the open source GPIO module that is included with Xojo and available on GitHub.
You can view all the Pi Projects here: