My vision of a smart home

    Hello Habrasociety!

    Watching the increase in topics about the smart home and under the impression that groups of people are created who are also interested in this topic ( Project of a completely free Smart Home ), I wanted to tell the community my vision of this product, how it can be made convenient and cheap.

    Tasks to be Solved


    Main goals:
    • User interaction - Means for displaying information and accepting commands from the user, for example, tablet computers with appropriate software;
    • Remote control - Means for executing user commands, such as turning on the lights, closing doors, etc.
    • Monitoring - Means of collecting information (temperature / light / harmful gas sensors / door openers / etc.);
    • Home automation - a computer which is a server for collecting information, storing the system configuration and executing control scripts;
    • Interfacing with adjacent systems - the system must interact with external devices such as TV, air conditioning, etc.
    • Data Transfer - Communication facilities of all nodes in a single network.


    With the help of the main tasks, a huge number of side tasks are solved, such as:
    • Access Control System;
    • Security alarm;
    • Fire alarm;
    • CCTV;
    • Video intercom;
    • Baby monitor
    • Remote control of lighting;
    • Automatic shutdown of electrical equipment at night and in the absence of people in the room, in order to save electricity;
    • A single access system to all information and any resources from anywhere in the home.


    At the moment, each of the above tasks has been solved, but they are not all combined into a single system.

    Practical solution



    Figure 1 - General block diagram of the system


    User interaction

    Currently, smart home systems for lighting control use expensive “smart” switches, costing from 500 - 1,500 rubles, which are disguised as ordinary switches. I do not like this approach.

    For user interaction, I suggest using cheap Chinese tablet computers with Android OS, costing about 2500 rubles. Tablet computers should be mounted on the walls. They can not only serve as switches, but also display a lot of useful information; output audio and video stream for video surveillance systems, video intercom, sound notification systems; serve as part of a video surveillance system; be a source of emergency lighting. Among other things, it looks more futuristic than classic switches.

    Remote management and monitoring

    To solve the problems of controlling electrical equipment, I met either industrial automation systems, or smart home systems using their own protocols, or sets of modules for arduino.
    Industrial automation systems are too expensive for home use, smart home systems with X10 protocols and the like are too little functional. Systems based on arduino are not a ready-made solution, for the application of such a system it is necessary to buy the necessary set of modules, make a case, draw on the breadboard the interface circuit of all these modules, etc ...

    In my opinion, the most correct option would be to create a unified module for each room, containing the most used functionality, and use third-party equipment or arduino to solve specific problems (for example, RGB ceiling lighting).

    The approximate composition of such a module:
    • Microcontroller
    • 1-2 220V simistor outputs (PWM with phase detection)
    • RGB LED Strip Control
    • 4 relays 220V 2A
    • 8x discrete outputs
    • 4 discrete inputs (closing / opening)
    • 1x IR emitter (control of household appliances such as TV, air conditioning, etc.)
    • 1x temperature and humidity sensor
    • 1x motion sensor input
    • 1x control input:
    • or 1x RS232 input
    • or 1x RS485 input
    • or 1x Ethernet input
    • 1x power supply from 220V


    I intend to connect such a module to a tablet computer via USB or via a serial port through an appropriate adapter. Thus, the tablet computer will receive commands via Wifi, Ethernet, or any other communication system and control the control module.

    Perhaps it makes sense to consider the development of this module as a standalone device with an Ethernet port so that it does not require an external computer.

    Home Automation & Data Network

    To implement this function, it is required to connect all devices to a single network, develop a communication protocol, organize a server for executing automation scripts.

    Data transfer network I suggest using Ethernet and Wifi. Their bandwidth will allow you to execute commands without delay, transfer large amounts of multimedia data (you need to organize a video broadcast from the camera to the tablet, if you suddenly want to see what you have with a parked car in the middle of the night and get out of bed too lazy). Also there is a floor the network itself can be used as a home network for file sharing and Internet access.

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