Here is a mini guide as well as a selection of hardware to get you started in the manufacture of a 100% DIY Raspberry Pi 3 home box: what model of Raspberry Pi to choose, accessories needed (SD card, 5V/3A power supply, box, UPS), which home gateway (Z-Wave, Z-Wave Plus, RFLink, Homebridge).
Which Raspberry Pi model to choose?
Of all the models of Raspberry Pi available, it is without contest the Raspberry Pi 3 which is best adapted to make a box home automation. In terms of gross power, this is the most powerful of the range as shown by this benchmark realized with the SysBench by the site f4bi. In addition to an Ethernet (10 / 100M) network port, it incorporates WiFi and Bluetooth LE connectivity, which avoids having to buy a WiFi or Bluetooth dongle separately.
We will reserve the Raspberry Pi Zero W for the realization of surveillance camera. Much more compact and powerful enough, it is very well suited for this type of project.
The Raspberry Pi 3 is delivered naked. Some accessories are optional to make a home automation box. After the installation and configuration of the home automation devices (although you can do everything without a screen or keyboard also following this tutorial), you can do without the keyboard, mouse and the screen. What remains essential
A power supply 5V 3000mA (3A)
A less powerful power supply may cause the Raspberry Pi 3 to shut down. You can recycle an old phone charger with a micro-USB connector provided it delivers at least 2500mA.
One (better 2) SD cards
The Linux operating system is installed on a micro SD card. Choose a class 10 card (read speed 50MB / s minimum) to ensure smooth operation. A capacity of 8GB is large enough to operate a home automation server but the trend is disappearing in favor of 16GB cards (for an equivalent price). Stay in the big brands to avoid the bad surprises. An SD card is not as robust as a flash memory SSD drive.
Buy a second SD card and clone the main SD card regularly (after each update, every month). In case of a failure, you can restart your server in a few minutes without having to reinstall everything. Follow this tutorial to learn how to back up an SD card.
Protective case (recommended)
The home automation server will become an important part of your home. You will be able to manage complex scenarios (lighting, thermostat, closing of shutters …), it deserves a little protection against dust. Circuit tracks and connectors are exposed to the outside, a metal object falling or coming into contact can cause a fatal short circuit. Here is a small selection of economic boxes. There are also packs including a 5V / 3A power supply.
Mounting box on a DIN rail in a switch cabinet
That is another possibility. There are boxes to be installed on a DIN rail in a control cabinet. It is a more pro installation but it has some disadvantages:
- Even if all the connectors are accessible, it is not easy to connect a screen and a keyboard. Maintenance must therefore be done using an SSH connection (see this tutorial to learn how).
- Home automation gateways (ZWave, RFXCom …) are available as slot, USB or expansion card (HAT) to connect to the GPIO connector of the Raspberry Pi. Depending on your device, the gateway Raspberry Pi will be connected differently to the Raspberry Pi. The DIN Rail case may become less relevant.
- Protecting the RPI with an inverter on DIN Rail is much more expensive.
UPS Battery Backup and surge protector
An UPS battery backup will bring several protections to your home automation server:
- Protect Raspberry Pi and accessories (gateways, sensors…) from electrical surges
- Protect the SD card and all data, scripts and scenarios. This should not dispense you from making a clone regularly.
- Ensure continuity of operation. The server can continue to retrieve information from the battery-operated sensors. This is the case, for example, of the door and window openings detectors, the control panel and the alarm siren. As soon as the current is restored, the server can once again drive the powered units to the mains.
- By adding a 3G key (how to do it on domo-attitude blog), the server will be able to notify you by SMS of a power failure and its recovery. Ideal when you go on holiday to ask a friend to go check the house (and empty the freezer!).
Buy Raspberry Pi 3 alone or in kit?
If you have material to “recycle”, keyboard, mouse, screen, SD card, you can buy your Raspberry Pi 3 alone. A home automation server does not need any accessories as we have just seen. You will need a keyboard, mouse, screen in the installation phase. Then, most home automation software offers a configuration interface accessible from any computer on the local network. At the worst, you can access the Raspberry Pi 3 using an SSH connection.
Add a gateway to communicate with home automation devices
Home automation devices use different protocols to communicate with a server or a home automation station. Depending on the technology used by your devices, you will need to add a gateway to communicate with them (temperature measurement, door opening or window sensor, flooding …), or to control them (lighting, siren alarm, open the shutters, turn on the heating …).
Z-Wave+ or RaZberry?
Open Source home automation software uses the OpenZWave project to communicate with Z-Wave devices. The Z-Wave Plus improves range and reduces power consumption, which is important for accessories that work mostly on batteries. The easiest way is to use a latest generation USB stick, cheaper and easier to include on the server.
Build an open source radio gateway RFLink?
You can build your radio home radio gateway using the Open Source RFLink project by following this tutorial. In addition to the 433MHZ, you can control 315MHz, 868MHz and 915MHz devices by adding additional antennas. The list of compatible devices can be found here.
With this Open Source project, you can control any home automation accessory from your iPhone or iPad. No additional hardware is required. All items that deal with Homebridge are here.