Raspberry Pi Homecontrol - Hardware

Since autum is approaching and the weather is getting more and more cold and wet outside I have some time again to play with my Raspberry Pi(s) and implement a basic “Smart Home” setup. At the moment it just measures the temperature and can switch some RF-controlled wall sockets on and off over the network, but at least its a start :) Maybe I will implement some more functionality in the future. This post will be the first one of several describing the setup and will focus on the hardware-side of things. Please note that this isn't meant as a step by step guide to building the hardware, but rather a quick overview with the links to all necessary documentation I used.

The setup uses the following Components

• A Raspberry Pi Model B
• A ComPi Module from ABElectronics UK providing 1-Wire and Serial connectivity (only 1-Wire is used at the moment)
• A RTC Module also from ABElectronics UK providing correct time if no network is available
• 4 DS18B20 1-Wire Temperature sensors
• A TX433N RF Transmitter

The 2 modules form ABElectronics are stacked on top of the Raspberry Pi's GPIO Header, as you can see in the pictures here:

The temperature sensors are connected to the grey cable, ending in a RJ12 plug. The pinout of the Plug can be found in the ComPi's datasheet

Last part of the setup is the TX433N RF-transmitter for controlling the plugs. Since the wireless range is rather poor I have attached the transmitter to the plugs directly:

The transmitter is connected to the PI as described in the hardware documentation of the rfbb project which is used to control it. The RF-plugs you see there are these ones from german electronics retailer Conrad.

So that's it with the quick overview of the hardware, the next post will focus on getting the RTC, 1-Wire and RF-modules to work on Arch Linux (my OS of choice for the PI), so stay tuned.