Using ready-made expansion boards

While it's much more satisfying to build your own stuff, you might want to look at buying some readily available expansion boards for your home security system if you're not yet confident with your soldering iron, or if you just simply don't have the time.

Following are some ready-made expansion boards that you can obtain; they should work as part of our home security system with a bit of modification to our scripts to support the libraries that are required by the hardware.

Hobbytronics MCP23017 expander port kit

This kit is almost identical to our own circuit in the previous section of this chapter. The kit comes with an MCP23017, a PCB, and various connectors. The boards are designed to be daisy-chained together so that you can have multiple expanders to give you more input/output ports. Note that this kit is not pre-built and requires soldering, but I thought I'd include it because it's the board that I use to build such systems when prototyping. You can...