Hardware

Felix currently supports 1-Wire and X10 hardware. There are many excellent websites describing 1-wire and X10 hardware, and there seems little point in replicating much of that information here. However, in case you are a complete novice, here is a basic introduction.

1-Wire

The really cool thing about the 1-wire network is that you can daisy-chain lots of devices onto the same pair of wires…

You can get started with just a PC interface, either USB or serial, some DS1820 temperature sensors, and some cable. The DS1820 is really easy to use, requiring only two connections and no power supply. For most home uses, you can hook up as many devices as you want, using cables about as long as you’d ever need in a normal house.

Each 1-wire device has a completely unique address burned into it during manufacture. Something like EF000800DB2A0610. This number allows software to uniquely address each device on the network, in order to read data from it, or send commands to it. You’ll need some software that lets you associate those addresses with meaningful names, like “Lounge”, or “Outside”. However don’t worry, Felix deals with all of that.

Many 1-wire devices can work with no external power supply, and most of the rest can work from a +5v supply carried by the same cable as the data. The recommended cable for wiring a 1-wire network is cat-5 unshielded twisted pair cable, the same cable used for wiring computer networks. For small networks you can use almost any type of cable and connect it haphazardly, but for maximum extensibility it makes sense to use the proper cable. If you get serious about 1-Wire, pretty soon you’ll need to get a stock of RJ11 connectors and a good crimp tool.

One of the weaknesses of the 1-wire network system is that there is no single standard in use for wiring, connectors, colours, or pin numbering. A number of manufacturers make packaged modules using 1-wire chips, but unfortunately they don’t all use the same connector standards. Some use RJ45, some use RJ11, some use RJ12. It’s a pity, and it’s probably the main reason why 1-wire is mainly used by people with at least some basic wiring or electronics skills.

Despite the wiring issue, 1-wire remains an extremely good solution for diverse sensing and monitoring applications. The wide range of chips available makes it relatively easy to construct almost any type of sensor at minimal cost, and there are a huge range of ready-made devices available.

A problem with using 1-wire devices to switch mains electricity is that it can be untidy and might not comply with regulations, especially in the UK, where we are no longer allowed to modify our own house wiring.

X10

X10 is at the other end of the automation spectrum. It requires no special wiring at all, sending all its signals through your existing mains wiring. Its packaging and functionality make it safe, simple, and legal for end users to implement remote control of all kinds of mains operated lighting and devices. However, lacking in sensors and adaptability, its inputs are limited to things like switches, remote controls, and motion sensors.

Despite its limitations, X10 is an excellent choice for control of mains powered devices, allowing you to implement mains power control safely and neatly.

Combining 1-Wire with X10

So 1-Wire is flexible but messy, and X10 is neat but limiting, and we wanted to use a combination of the two. That’s why we ended up writing our own software. Felix grew from the sheer necessity to use 1-wire devices for sensing and monitoring, and X10 devices for control of mains power. It has proven to be an ideal combination.