Although not many people can see the need for having their smart fridge connected to the Internet, most people will find the ability to remotely control lights, security cameras and other home appliances very useful.
If you are thinking about adding smart devices to your home then this guide to home automation will give you a good basic understanding of how smart devices connect and are controlled.
What is Home Automation?
Home automation or domotics is building automation for a home, called a smart home or smart house. It involves the control and automation of lighting etc –Wiki
Home automation is one of several areas of the IOT (internet of thing), and is often called Home IOT.
There are three distinct levels of home automation.
The ability to view status of systems i.e
- What is the temperature?
- Is the door locked?
- Is The Light on or off
The ability to change the state of a systems i.e
- Turn up the heating.
- Lock the Door
- Turning the light on or off
The ability to change the state of a system automatically in response to an event. i.e
- Turn on the heating if the outside temperature falls below a certain temperature.
- Turn the lights off when no one is a home.
Currently most home systems are at the control level.
Home Automation Components
A home automation system will consist of
- End Devices like switches,sensors,lights,locks etc
- Connection devices like hubs and Gateways.
- A Network or networks
- Internet connection -maybe optional
Networking- Wi-Fi, Zwave, ZigBee,Thread, Bluetooth
These are all wireless protocols found on home automation networks.
Current home networks used for connecting computers and other devices to the Internet are Ethernet and Wi-Fi based.
They also use TCP/IP as the networking protocol.
Logically home automation devices and products would just attach themselves to this existing network which would mean that they also would use Wi-Fi and TCP/IP.
Wi-Fi is ideal for transmitting large amounts of data across a network (e.g video,but has a high power consumption.
Home automation devices like door sensors, temperature sensors, lights etc don’t need to send large amounts of data, and in many cases may be battery operated.
Therefore Wi-Fi wasn’t considered a suitable protocol for use in these devices, hence the development and use of Zigbee and Zwave wireless standards and proprietary protocols in home automation products e.g Philips Hue (Zigbee).
Devices using ZigBee and Zwave form their own network independent of the existing home Wi-Fi network ,but can be connected to the existing Wi-fi Network using a suitable hub.
Thread is a newer standard sponsored by Google and uses IP networking ( zwave and Zigbee don’t) but uses 6lowpan and not Wi-Fi.
The Diagram below shows an example network:
There are several different types of end device:
- Devices that work using a remote control like a TV and cannot be connected to a home network.
- Devices that use Wi-FI and TCP or UDP over IP as the networking protocol. These connect directly to the existing home Wi-Fi network and are usually controlled via an App on a smart phone. They can also be controlled via a hub like Amazon Alexa.
- Devices that that use Zwave or Zigbee will require a hub to connect to the home network and the Internet.
- Devices that use proprietary protocols like Mi|home
Hubs and Gateways
If your end device supports Wi-Fi then it can connect directly to you existing home Wi-Fi network, if it uses Zigbee,Thread or Zwave then it will require a hub of some sorts (diagram above).
However hubs can perform other task besides interconnecting products using different protocols.
They can also provide Gateway functions e.g. converting your sensor data to MQTT.
Smart hubs will generally provide a User Interface that allows you to manage the individual devices, and to set up automation rules.
This can be via an App on a smart phone or tablet or web browser.
TCP/IP Hubs can be located on the Home network or on the Internet.
Amazon Alexa is an example of an Internet based hub that is becoming very popular.
Some home automation systems may require an Internet connection to operate.
For example if you are using Amazon Alexa to control your home devices then you will need an Internet connection.
Other Home automation hubs are standalone e.g. Homeassistant and don’t require an Internet connection to operate.
Controlling Smart Home Devices
Because of the popularity of smart phones, most smart home devices and systems can be controlled using an App on a smart phone or tablet.
However devices from different manufactures will have a different App, and going back and forth between Apps is not very convenient.
Below is a screen shot from my Tablet showing the Apps to control several Wi-Fi smart devices from different manufacturers.
Not only is it very inconvenient to keep switching between Apps, the Apps can’t talk to each other, and you also need to install them on all devices that you use to control these devices.
However most of these devices can also be controlled by a hub like the Samsung Smartthings, Amazon Alexa etc.
Generally when you have several smart devices, especially when they are from different vendors then using some form of Hub to combine them is the best option.
Voice control using devices like Amazon Alexa are becoming more popular, and are much easier to use.Almost all devices being introduced today are being designed to work with ALexa and Google Home.
- Stack exchange-Do I need a hub for some devices?
- Can Zigbee be used without a hub
- See Toms Guide-Home automation primer –