It's now time to assemble our project. As we are going to use most of the Yún's connectivity, such as the USB port, it will be quite easy and quick to assemble the project. First, simply put the formatted micro SD card into the SD card reader of the Yún, which is located below the Yún board, as shown in the following image:
Then, plug the USB camera into the Yún USB port, as shown:
Finally, you need to connect the PIR motion sensor to the Yún board. It basically has three pins: VCC, GND, and SIG (signal pin). Connect VCC to the Yún's 5V pin, GND to the Yún ground, and SIG to pin number 8 of the Yún. You should end up with a setup similar to the following image:
Finally, you can connect the Yún to your computer via a micro USB cable or power it with a USB adapter if you want to use the project remotely and upload the Arduino sketches via Wi-Fi.