DIY home security systems come in all shapes and sizes. Some systems come with an LCD panel that serves as the brains of the system. The panel is typically installed on a wall in a central area of your home and connects wirelessly to your home network. Most of these panels use capacitive touch screens and contain multiple radios that allow them to wirelessly control Wi Fi, Z Wave, Zigbee, and Bluetooth sensors and home automation components. Most panels also contain a cellular radio that connects them to a monitoring center if you subscribe to a professional monitoring plan, and they almost always have a speaker and a microphone for two way communication with a monitoring agent. The cellular radio is also used to push updates to the system. For example, the $229 SimpliSafe Foundation is a starter kit that gives you the hub, a door/window sensor, a motion sensor, and a yard sign. Additional door/window sensors go for $14. 99 each and you can order glass break detectors for $34. 99 each, smoke detectors for $29. 99 each, and water sensors for $19.