The following guides are more up to date:

• https://learn.adafruit.com/adafruit-io-home-security for IR detection + cloud
• https://learn.adafruit.com/cloud-cam-connected-raspberry-pi-security-camera  for camera 

Ever saw these wireless security cameras that you can buy off the shelf? These are devices that you can setup somewhere in your home or outside, connect to your WiFi network, and then access the video stream from anywhere. However, they are usually using the interface given by the manufacturer, which means you are quite limited with what you can do with your camera.

In this project, we are going to build our own DIY version of such devices. The project is based on the Arduino Yun, to which we are going to connect a standard USB webcam and a PIR motion detector to create some cool applications.

The first application will be a modern version of standard tasks that you want for a security camera: taking pictures when some motion is detected. The project will store pictures taken by the USB camera on an SD card inserted into the Yun, but that's not all. Because we are in the age of the Internet of Things, we also want these pictures to be automatically uploaded on a secure location. And that's exactly what we are going to do by uploading the pictures to Dropbox at the same time.

Then, we are going to stream video coming from the camera directly on Youtube. At the end, you will have your own video stream accessible from anywhere in the world so you can check what is going on in your home. This way, you can also just share the link with your family or friends, so they can monitor your home when you are not there. Excited? Let's dive in!