But if you don’t need the value-added features such as a weather-resistant housing that can be chained to a tree, this DIY motion ... PIR sensor and an optoisolator, with a battery, a plug ...

The Arecont Vision NVR offers the choice of 8 or 16 channel models (one channel = one camera sensor), each with built in PoE network switch, customer-replaceable hard drives, and Arecont Vision GUI ...