Smart Homes : beneficts, protocols and applications
Over the last ten years, we have all become accustomed to managing different aspects of our lives through technology; from banking to shopping online, the internet has made our lives much easier. A similar revolution is taking place in our homes today.

Over the last ten years, we have all become accustomed to managing different aspects of our lives through technology; from banking to shopping online, the internet has made our lives much easier. A similar revolution is taking place in our homes today.

What is home automation or smart home technology?

The smart home is a home where almost everything, or almost everything, can be controlled by a digital device. Doorbell, lighting, alarm, heating, water and even closing your curtains. Technology allows you to monitor and control everything remotely.

What are the benefits of a smart home?

 Smart technology allows you to manage your home much more easily and efficiently, and ensures that everything works perfectly, so you can go away for a long time with peace of mind. Some technologies simplify the organization of your home, limiting the need for wires and remote controls for your TV and music. The one that controls lighting and heating improves the comfort of your home by turning on lights and remote heating so that everything is ready when you arrive.

Some home automation technologies are more focused on security, such as an integrated intelligent surveillance system that keeps an eye on what's going on, wherever you are. You can also purchase systems that protect your home from fire and flood hazards. The smart home gives you a feeling of being more in control and better informed about what's going on in your home.

How does home automation work?

Depending on your priorities, you can introduce home automation technology room by room. If opening your curtains with your voice is your priority, start with this! However, the trend is more towards an integrated technology that connects on a single platform the different elements of your home.

Which protocol to choose for home automation?

The home automation protocol is the language used to establish communication between the various connected devices. To be able to communicate with each other, two devices must therefore have the same communication language, i.e. the same protocol.
There are several protocols in home automation. Thus, when opting for a technology in home automation, it is necessary to have connected devices and objects that share a similar protocol. Two kinds of protocols are used:

1-Short-range protocols

Z-WAVE

It is a communication protocol dedicated to home automation. Z-wave is a wireless protocol appreciated for its ease of installation and its range of about 30m. The network operates according to a mesh which implies that all the objects connected to the system emit data and are able to relay the information transmitted by its neighbors. Thus, this mesh will be able to extend the range of the devices.

Z-Wave is a bidirectional status feedback technology that ensures that the given orders are executed as required. This protocol also stands out for its speed and reliability compared to a 32-bit code, which blocks any equipment that does not have the appropriate code. The technology used by Z-Wave is a low-power radio technology in the 868.42 MHz frequency band.

The Z-Wave communication protocol allows the connection of up to 232 devices and can be used on a very wide range of products, all at affordable prices compared to some wired technologies. In addition, Z-Wave is easier and faster to use.

ZIGBEE

ZIGBEE is a mesh network allowing the transfer of a big volume of data. Moreover, compared to the Z-Wave, it allows to transmit a more important volume of data but it is less expensive and easier to use. The average range of this communication protocol is 100 m.

Zigbee is based on the IEEE802.15. protocol, an industrial wireless network operating at 2.4Hz that targets applications receiving a small amount of data in a limited area.

Zigbee has many positive features, including low power consumption, reliability, scalability and robustness. This protocol is well placed within machine-to-machine systems and IoT applications.

WI-FI

WI-FI is a universal protocol allowing the fast transfer of a large amount of data. It is a wireless broadband transmission technology using radio waves. The term "Wi-FI" is the name of the IEEE 802.11 standard, which is the international standard describing the characteristics of a wireless local area network or WLAN.

This communication protocol uses radio frequency to allow two devices to communicate with each other and also allows routers to be linked to various devices such as PCs, tablets or smartphones.

WI-FI is also used to connect objects and is a very widespread technology. It uses a large bandwidth and requires a fairly large amount of energy. Thus, it requires high power consumption and quite expensive components, which means that the vast majority of designers of connected objects still ignore it.

BLUETOOTH

Bluetooth is a communication protocol invented in 1994 by the Swedish company Ericsson. It is a standard for wireless data transfer using low bandwidth that allows it to transfer only a small amount of data over short distances.

Nevertheless, Bluetooth is very energy-efficient and is included in almost all cell phones and smartphones and other connected objects. Bluetooth also has many applications (smartwatch, heart rate monitor, wireless headset, etc….).

2-Long range protocols

LORA

This is a low-power, low-cost protocol that allows data to be transferred over very long distances. In fact, it has a range of two to five kilometers in urban areas and up to forty-five kilometers in rural areas.

The Lora communication protocol targets a wide range of applications and has been designed to offer a low-power connection with features that enable it to support secure two-way mobile communication for connected objects.

Lora is very energy efficient and is able to support large networks for data transfer. Nevertheless, this protocol can only pass through 0.3 to 0.5 kilobits per second.

SIGFOX

Sigfox is a communication protocol with a range that is positioned between the WI-FI and the cellular connection. In an urban environment, it has a range of ten kilometers and it can go up to fifty kilometers in the countryside. Sigfox uses free ISM bands to transmit data in a very narrow spectrum to or from connected objects.

The Sigfox protocol has a very large number of machine-to-machine applications operating with a low volume of data and uses a technology called Ultra Narrow Band. It is specially designed to handle low data transfer speed and requires low power consumption.

However, this communication protocol can only carry very small amounts of data (between 10 and 100 bits/second maximum). While it was initially monodirectional, it now allows information to be sent to the connected objects despite the impossibility of carrying out large updates quickly.

Sigfox is already deployed in more than 10,000 connected objects and is used in major European cities. It is a robust protocol that is able to communicate with millions of battery-powered devices over distances of several square kilometers thanks to a network that is interesting for machine-to-machine applications.

CELLULAR

These are networks based on GSM (2G) technology that are provided by mobile operators and allow the transfer of a large amount of data over a long range.

Mobile cellular networks require a SIM card to be installed in the device to be connected in order for it to be identified on the communication network. The fourth generation (4G) of cell phone standards allows very high speed mobile communication.

ENOCEAN

It is a very energy-efficient communication protocol for sending wireless and battery-free radio frames. Enocean uses the 868 MhZ band and an autonomous technology that draws energy from its environment in order to transmit a signal and communicate with other products using the same protocol.

Easy to use and install, Enocean uses peripherals that require minimal maintenance because they do not use batteries and therefore consume very little energy. This also has the advantage of extending the lifetime of the connected objects.

The Enocean communication protocol works in a very simple way and does not necessarily require a home automation controller. Indeed, Enocean is 100% Standalone. The majority of the new products of this protocol are bi-directional and can be used as WI-FI repeaters.

Its wireless range goes from 30m indoors to 300m outdoors depending on the environment and the conditions of use. In addition, it should be noted that every Enocean product is defined by an "EEP" equipment profile developed by the Enocean alliance. This is an open and interoperable international standard.

Design and realization of a Smart Home prototype

This prototype was realized by the students of the 3rd year of a Moroccan Engineering School (ISGA Marrakech): Mr OUNAYN, Mr KILILI, Mrs ISMAILI, Mr EL ABDI with the supervision of Mr REHA, Mr BOUCHOUIRBAT, Mr GOUCHEG and Mr SATAR. This is a summary of the project :

Presentation of the Smart Home Prototype

As shown in Figure 1, the smart home prototype is composed of three rooms, a hall, a garage and a garden with a part that can be covered. This prototype is made of wood with the dimensions 60 cm * 45 cm * 30 cm. The walls are 2 cm thick.

Figure 1 : The smart home design

To simulate the operation of this smart house, several sensors have been implemented:

Sensors for general operations

1-Weather station

Monitoring the weather is a daily necessity, so we designed a system that tracks the temperature, humidity, and brightness inside the house. These parameters will then be displayed in a LCD (24*4) and used to perform the following automatic actions:

  • Automatic activation of the air conditioning as soon as the temperature exceeds 27°C.
  • Automatic and adaptive switching on of the lights in the garden.
    To measure these parameters we used a DHT11, and a photoresistance (figure 2).
Figure 2 : DHT11 sensor

2- LDR5516 Photoresistance Module

This module is based on an LDR (Light Dependent Resistor and an LM393 amplifier). The module has one digital and one analog output. The sensitivity is adjustable via a potentiometer (for the digital output). The module can be connected to a digital or analog input of an Arduino board or others (Figure 3).

Figure 3 : LDR5516 sensor

Communication sensors

1-HC05 ZS-040 Bluetooth Module

This system is characterized by the high speed of data transmission. On the other hand, its range is only a few meters. This is not a disadvantage, but the Bluetooth standard is designed for very limited ranges (Figure 4). For this reason, other communication modules with greater range such as Wifi and GSM have been implemented.

Figure 4 : HC05 ZS-040 Bluetooth Module

2- ESP8266 Wifi Module

This system is characterized by a greater range than the Bluetooth module, up to 140 m. However, the transmission time is slightly longer (Figure 5).

Figure 5 : ESP8266 Wifi Module

3-SIM900 GSM Module

The major advantage of this solution is its range, which extends to thousands of kilometers as long as there is GSM coverage to send an SMS (Figure 6). The disadvantage of this module and the transmission time which is significantly longer compared to the other two Bluetooth and Wifi modules.

Figure 6 : SIM900 GSM Module

Security Systems

The purpose of the security system is to prevent malicious intrusions and housebreaking. Despite the existence of new technologies, such as integrated smart cards, the industry standard is still the electric lock when maximum security is desired. To achieve this, we have installed an automatic access system controlled by an identification card, as well as an alarm in case of a breach.
The principle is as follows: each resident has a single configured card. To open the lock, they only have to present it once in front of the card reader. If it is the right card, a new message will appear on the LCD display. If it is the wrong card that has been inserted, the door will automatically lock and an alarm will ring to notify the owner of the house. To close the entrance again, simply reinsert the card, which this time will send us another message on the LCD display indicating the door is closed. The sensors used for the security system are :

1- RC-522 RFID Module

This system is composed by a reader and RFID Tags as shown in figure 7. This system uses the standard RFID 13.56 MHz which is characterized by its short range.

Figure 7 : RC-522 RFID module and the two TAGs (key ring and card)

2-MQ-2 Module

Another life-safety precaution is the installation of a gas detector. Figure 8, shows the gas detector (Butane, Methane, Propane) used.

Figure 8 : MQ-2 Module

Other sensors for comfort and energy optimization

1- Rain detector

The rain detector used unfortunately has no reference, but it is available at the sensor vendors (Figure 9).

Figure 9 : Rain detecor

2- Motion detector

The PIR HC-SR501 is a sensor used to detect movement. It detects infrared radiation in its field of view and infers a presence or movement (figure 10).

Figure 10 : PIR HC-SR501 Motion detector

3- Fans

If a threshold temperature (27C) is exceeded, for example, a fan is activated to simulate the operation of an air conditioner. Also, in case of gas and smoke detection, a fan is activated in the opposite direction to evacuate the smoke. We used mini fans as shown in figure 11.

Figure 11 : Axial Fan Cooler

Operations and Applications

Most of the features of the Smart Home are done in an automatic way to ensure a more comfortable life for the users, but these same features can also be done manually.

1- Access (Door-Garage-Window)

Access to the house is as shown in Figure 12.

Figure 12 : Access to the Smart Home

2- Garden Features

The features installed in the garden are summarized in the schematic of figure 13.

Figure 13 : Control of the garden functionalities

3-Security

The diagrams shown in Figures 14 and 15 illustrate the functionalities of security. To access the house or the garage, an RFID card must be presented. If the right card is presented, the doors open if not, an alarm signal is triggered and a message is automatically sent to the owner (Figure 14). Similarly, if the presence of gasses is detected, the ventilator will be activated and a message will be sent automatically (Figure 15).

Figure 14 : Home security (Access by RFID card - Surveillance camera)
Figure 15 : Securing the Smart Home(Gas detector)

Global electrical diagram and Photo of the completed prototype

Figure 16 shows the global wiring diagram of the Arduino board with the different sensors. Figure 17 shows the realized prototype.

Figure 16 : Global electrical diagram
Figurw 17 : The completed prototype (ISGA Smart Home System)

INTERNATIONAL SYMPOSIUM ON CONNECTED SYSTEMS AND OBJECTS COC19 (Presentation of the project)

References

[1] Cédric Locqueneux, Serge Darrieumerlou, Le guide de la maison et des objets connectés: domotique, smart home et maison connectée, Eyrolles, 2016.

[2] Méziane Boudellal, Smart Home: habitat connecté, installations domotiques et multimedia, Dunod, 2014.

[3] François-Xavier Jeuland, Olivier Salvatori, Réussir son installation domotique et multimédia: la maison communicante, Eyrolles, 2007.

[4] Marc-Olivier Schwartz et Al, Arduino pour la domotique, 2015.

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