Here's a list of parts that you will need to build one:
- USB power supply
- USB power cord
- 5VDC relay
- A zigbee/z-wave contact sensor with external contacts (I use a GoControl WADWAZ-1 - $7 on eBay).
- A project box to put the relay and contact sensor in
Takes about 15 minutes to build. Here's what my finished sensor looks like:
