HomeAutomation Report

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HomeAutomation

A Full-Featured Infrastructure-Less Home Automation System

Project reportUbiquitous Computing

Joakim Brjesson, Victor Strm, Yiqi Mao,Kadri-Ann Valgevli, Amir Sabbagh Pour

CHALMERS UNIVERSITY OF TECHNOLOGY

Gteborg 2008


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HomeAutomation

Joakim Brjesson, Victor Strm, Yiqi Mao, Kadri-Ann Valgevli, Amir Sabbagh

Pour

Brjesson, Strm, Mao, Valgevli, Sabbagh Pour 2008.

Chalmers University of Technology

412 96 Gteborg


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AbstractThe HomeAutomation is a wireless home automation system that is supposed to be

implemented in existing home environments, without any changes in the

infrastructure. HomeAutomation let the user to control the home from his or her

computer and assign actions that should happen depending on time or other sensor

readings such as light, temperature or sound from any device in the

HomeAutomation network.


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Table of ContentsProject report

Ubiquitous Computing 3

Joakim Brjesson, Victor Strm, Yiqi Mao,

Kadri-Ann Valgevli, Amir Sabbagh Pour ............................................................................3

Abstract 5

Table of Contents 6

1 Introduction 7

2 Background 8

3 Concept 9

4 Realization 10

4.1Network.............................................................................................................................. 10

4.2 Software ................................................................................................................................. ......... .12

4.2.1 User Interface ............................................................................................................................12

4.2.2 Program evolution and inner workings .............................................................................13

4.3 Electronics........................................................................................................................... 13

4 .3.1 Arduino ........................................................................................................................14

4.3.2 Dimming/switching circuit .................................................................................................14

4.3.3 Wireless modules ...............................................................................................................15

4.4 Prototyping and construction............................................................................................ 16

5 Evaluation 17

5 .1 Electronic Blocks .......................................................................................................... 17

5 .2 Pen Timer ...................................................................................................................... 17

5 .3 Control4 ..........................................................................................................................18

6 Discussion 19


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HomeAutomation Project Report2008-12-19

1 IntroductionThis report is describing our group project in the Ubiquitous Computing course. It is

containing the design process of the project, starting with brainstorming we had to

get the final product idea and finishing with the prototyping within home alike

environment. The original problem was to design and implement a larger ubiquitous

computing project into a home environment.The report is describing what kind of

design process, hardware and software have been used to build up the prototype for

that product design that we had chosen as our final goal.

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3 ConceptEvery HomeAutomation box is a stand-alone device. It is connected to the mains and

controls the power outlet of the electrical device that is plugged into it.

There will be a receiver and transmitter in each of the box, so they can exchange

information with the master (a computer). People can control power supply of

electrical devices in order to create an interactive home environment to facilitate the

control without changing any home appliance. People can enjoy the high

technology and simplicity modern life style.

Each device will be with standard setup and while adding it into network; it can be

given an address and tasks to do. All the setting will be easily resettable to default

value, so people can move the devices between different electrical devices and

networks.

HomeAutomation boxes will be put into different rooms at home, depending on theneeded functionality. Various different sensors could be attached to the boxes. The

sensors are used as triggers for actions, that user can set up in the computer program.

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4 RealizationThe project started off with a brainstorming session. All ideas about how the

HomeAutomation should work and what functions it should have were written on a

whiteboard. We discussed all possible solutions and ideas that we had come up with

and removed things that were not possible to implement within this project scope.

All that was left on the whiteboard in the end was divided up into following task

areas:

Network

Create a wireless connection between embedded Arduino boards and the

computer program. To define a protocol for serial communication that both

Arduino and computer program can read.

Software

Computer software has to be able to control the communication, send tasksfor HomeAutomation embedded devices and be provided with the GUI where

end users can set up actions.

Electronics

This area covers in detail the hardware solutions chosen and how that

affected the final prototype. The hardware could be described as three

different work areas: arduino, dimmer/switching circuit and wireless

modules.

Prototyping and construction

The last focusing area is prototyping the final product. We need to build the

product and put it into aesthetic form. The presentation of the project shouldbe done so the visitors understand how the final product is supposed to be

used. Therefore we have to come up the suitable scenarios to present. Some

furniture is needed to get a home environment feeling for the presentation.

4.1Network

The first task for network was to get two Arduino boards communicating with each

other via serial communication. After some struggle with the wired connection we

got it working. One of the Arduinos was sending a message and second one as

echoing it back. On the same time, part of our group was working with trying to

establish a wireless connection. The wireless components that we used are called

Easy-Radio transceiver. These components could work both as transmitter and

receiver, which fit perfectly for our project. It took some time to find out how to get

the wireless communication working. After some testing we managed to echoing

messages back with the wireless components as well. Now it was possible to send

serial data over a wireless connection and it was time to test it with some more

advanced Arduino code.

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Figure 1: Wireless Connection between Computer Program and Arduino

To be able to try this out properly we had to come up with a protocol to use. A

protocol describes how the packages that are going to be sent, how the

communication is structured and what the sent/received bytes stand for. It is needed

for the receiver to know how much and what kind information it is reading and how

to should handle it. For a sender, a protocol gives the rules for what and in which

order to send the data.

The protocol we decided to use is a custom made, 40 bits long one:

The first 8 bits for house code to identify that the HomeAutomation devices

that you are controlling belong to your home network.

Following 8 bits was for unit identification to make sure that the correct

device responds to the message. In our implementation the computer program

broadcasts the message to all devices. Therefore it is needed to have

addresses assigned for the devices.

Next 8 bits was assigned for function code. This tells to the device what taskneeds to be executed. For example if a lamp should blink or fade etc. The

default function is a function that asks if anything have changed.

The last 16 bits of the protocol is used to send values for the specific function

that is being used. For the default function bit 1-4 is used for telling if

connected digital sensor have changed, 5-8 if analog sensor have changed, 9-

12 is used for telling if a digital sensor have been plugged in and 13-16 if

any analog sensor have been plugged in.

The network that we created that is using this protocol is a master/slave network. The

computer is the master and all the other devices are slaves.

Figure 2: Sketch of the Network with One Master (the Computer) and Four Attached Units.

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The computer is asking each slave, one at a time, if anything has changed since last

time.If something have changed then the slave will reply and tell what that have

happened. If nothing has changed the slave will reply with that.

When the master receives the reply from the slave that says that something has

changed it will check if there are any actions that are triggered on the changes. Those

actions are made in the computer software (4.2 Software). If there are actions that

should be triggered the master will transmit information to the affected slaves and

tell them what to do. For example if the party button have been pressed (digital

sensor changed/ high/low) then tell a device to start blinking.

Figure 3: Easy - Radio Wireless Modules

4.2Software

In parallel with the Arduino code being programmed, the software for the computer

was created. The software is to be installed on the end user's computer in order to set

up and run the HomeAutomation network at home. The program is written in Java, a

language chosen because of the existing knowledge about the language in the group

and the in-built cross-platform support.

4.2.1User Interface

The main user interface is divided in two parts, the main panel with all connected

devices and their status and a table of all currently configured actions and their

priority.

4.2.1.1 Device Panel

The device panel is a horizontally scrollable list of all connected devices, which can

be described by a custom name. For each device you can see all connected sensorsand their status. You can also in real time control each device, for example set a

lamps intensity to medium intensity or slowly fade another from off to fully lit and

query the current status of the devices controllable outlet.

4.2.1.2 Actions

One of the main features of the program is the ability for the user to configure

actions. An action is a kind of if-then clause. For example: If the night lamp lights

up at night then set all hallway lamps to half lit. The user can also assign a custom

name to each action to make it easy to associate the action with what is performed.

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Below the list of devices there is a list of all currently configured actions and their

priority. The actions priority can be changed and the actions themselves can be

edited and deleted. If the Edit button or then Add new action is clicked, a new

dialog is opened where the user can create or edit new actions to produce the kind of

if-then clauses described above. Actions can have an arbitrary number of inputtriggers and output actions.

4.2.1.3 Other Functions

Apart from the two abovementioned core functions of the user interface, there are

also a few assorted functions to be able to setup the network properties and to

monitor the network activity and the messages getting transferred.

4.2.2Program evolution and inner workings

The first version of the computer software was a basic program for testing out the

serial communication using the custom made protocol. It had a simple graphicalinterface for creating packages to be sent to Arduino and to monitor incoming

packages. The actual communication is taken care of by a Java library called Java

Communications API (Sun Corporation, 1998), which provides access through the

Java Virtual Machine to the hardware Com port on different platforms.

Next iteration of the program was model the actual devices. Every attached device is

modeled as an instantiation of the device class, which keeps track of the devices

state and provides an interface to communicating with it. Every time a message is

decoded it is propagated to the device affected, which in turn updates its own state

and notifies any subscribers to its changes (the graphical user interface for example).

After the implementations of devices followed the implementation of the actionsdescribed earlier. One class keeps track of all actions and registers as subscriber to

any changes for the devices used as input triggers for the actions. It then, according

to the priority of the actions, relays the state of all connected devices to each action.

The actions class then checks if the current world state matches the requirements set

in its input triggers and, if that is the case, performs the actions configured by the

user. Each device affected by an output action gets flagged, thus making sure no

device gets controlled twice during the same state update.

4.3 Electronics

ZDC circuit generally detects if the input signal crosses the reference point (0v in our

case) and produces an output state change.

This circuit consists of two opto couplers in parallel.

They are directly connected to main voltage. Each of these opto couplers works in

half cycle of the AC voltage signal, and outputs are connected in parallel, so we'll

have four state changes per cycle at the output of the opto couplers. It will be used by

the Arduino for future actions.

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Figure 4: ZDC Circuit

Figure 5: ZDC output signal

4.3.1Arduino

We have used Arduino to detect pulses from the ZDC circuit. The signal from ZDC

goes to Pin3 of Arduino which is defined as external interrupt handler (INT1). For

each pulse the interrupt will be triggered and a timer inside the Micro controller

(MCU) will be set with the desired interval. The output from the MCU is a digital

output from Pin Number 5 which goes to the Dimming/Switching circuit

4.3.2Dimming/switching circuit

This circuit includes an Opto coupler-triac driver which triggers the triac gate. The

triac simply acts as a switch. By switching the triac we can control the output

voltage, therefore we can have an AC light dimmer. When Microcontroller sends a

positive pulse to the opto coupler (EL503), it will trigger the triac via the triac gate.

Triac keeps onstate until the phase voltage reaches 0v. If you feed the triac gate

with a permanent High signal, it will remain in the on state, so it will act as a

normal switch.

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4.3.3Wireless modules

These modules operate on the Pan-European 433Mhz frequency band from a 3.6v

power supply. There are 9 frequency channels available on each module. You can

use encryption for the transmitting data. The baud rate is set to 19,200Kbps by

default. The range can be extended by using the proper antennas up to 250m Line Of

Sight (LOS). (Low Power Radio Solutions Ltd., 2003)

Beside these circuits we have added an LED, push button and also two general

purpose digital/analogue inputs for each box. The LED indicates that the related box

is powered on and is working properly.

By pressing the push button on the box, a new address will be automatically assign to

the box from the PC.

Its possible to connect different kind of analogue/digital sensors to each box. When

you plug in the sensor connector you can see in the software if its connected

properly or not.

Figure 6: Whole circuit

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4.4 Prototyping and construction

To be able to present our product it was needed to make the boxes where the Arduino

boards with the needed circuits will be placed in. After some research and discussion

within the group, we decided for using time switches. These are suitable for this

purpose and they already have the power connector. We removed the microcontroller that originally it had inside and replaced it with our dimmer circuit and

power supply module. Some modifications were needed on the cover to make holes

for digital and analog sensor connector.

As the space was quite limited inside the time switch box, we created a separate box

for the communication module. It had the Arduino board and Easy-Radio module

inside it.

Figure 7: Arduino board inside a box of time switch

In order to present the functionality of the technology, we chose to build a party

mode scenario. It blinks and dimmers the lights and turns on radio. For that purposeone special digital sensor was created. It was a normal switch but we made it into a

big red button to attract attention. The HomeAutomation devicesthat has this special

box attached to, reads this sensor value (recognizes if the button was pressed). When

the party-mode-button is pressed the devices enter a party-mode-state. The specific

events of the party-mode can be assigned in the computer GUI software.

Figure 8: The Christmas Mode Button

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5 EvaluationDuring the exhibition we let people to try the system. Most people found it

interesting and they appreciated the idea to automate their home environment. It

made them think about automated actions that they would like to have at their home

environment. When we explained a few examples where HomeAutomation could be

used they were very fast at coming up with their own examples.

The party mode was introducing the product's functionality quite well. Unfortunately

we could not let people to play around with GUI program to define their own actions

due to some software issues.

Once a while we experienced some problems within our system and we had to reset

our devices, but overall working experience was good.

The feedback we got was mostly positive. We were also told that the system speed

should be much faster in order to be successful product. During our presentation it

took more than 5 seconds for all devices to start their tasks.

Due to the time limits we were not able to present our second scenario that we had

thought. We wanted to show the analog sensors. We had created 2 LDR sensors and

we wanted to perform a use case that if you turn of one lamp then 2 other will dim

down to 50% and if you turn off 2nd lamp that the 3rd one will be turned off as well.

We didn't get the analog sensor detection working properly within the time we had

and also the analog sensor reading was producing much communication in the

system that made it even slower. Related work

5.1 Electronic Blocks

Electronic Blocks is a programming interface for children between three and eightyears old. There are three kinds of blocks in the project: sensor blocks, action blocks

and logic blocks. The sensor blocks detect light, sound and touch. The action blocks

are able to produce light, sound and movement. The logic blocks are controlling the

signals between the sensor blocks and action blocks. By connecting those blocks

with each other children will be able to program their own structures. For example a

robot might be able to follow light. (Wyeth & Wyeth, 2001)

Figure 9: The Electronic Blocks

5.2Pen Timer

The timer is a white board with a groove in the middle; it can control the electrical

devices when they connected. The only thing to do is use a pen to draw a line on the

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groove, the LEDs will turn on, and the timer works. As time passes, LED will go out

one by one, and the line at the same time will be wiped after power cut off. It also

can set "break time" mode for the electrical devices. Users can draw lines without

continuous line to meet their needs, so that power can get through these times.

(Huang et. al, 2005)

Figure 10: The Pen Timer

5.3Control4Control4 is the full home automation system that is available on the market. It is an

advanced system that supports lightning, climate, home theater solutions. People

need to build in the infrastructure into their home walls. The systems are

controlled remotely and all electrical devices remote controls will be replaced with

the Control4 remotes. (West et. al., 2003)

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6 DiscussionThe HomeAutomation could be developed further by making it more stable and put

more effort on the visual design of the product. We could reduce the size of the

product by replacing the power supply module and Arduino microcontroller with

much smaller pieces.

All the devices could be equipped with IR receiver to control the electrical devices at

home that support the IR communication. More sophisticated actions and scenarios

can be created with this. IR commands enable larger variety for controlling electrical

devices that only the power outlet.

A lot of improvements could be done in the computer program as well. It should be

more customizable for an end user and it should have some password protection for

security reasons. It would be also nice to make it web-based so that users can control

their home remotely.

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7 ConclusionHomeAutomation is undeniably a resource which can make a home environment

automated. People can control their electrical devices via these HomeAutomation

devices and set up the controlling actions in the computer. We think this product

have high potential for marketing in the future. At the moment the components are a

bit to high to be able to produce these devices for a interesting price.

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8 ReferencesWyeth, Peta, Wyeth, Gordon (2001),Electronic BlocksTangible Programming

Elements for Preschoolers, University of Queensland, Brisbane, Australia.

West, Smith, Morgan (2003): Control4 Home Automation, Tillgnglig:

(2008-12-18).

Low Power Radio Solutions Ltd. (2003), Tillgnglig:

(2008-12-18).

Henry Huang, Jack Chang & Howard Yu (2005),Pen Timer, Tillgnglig:

(2008-12-18).

Sun Microsystems (1998),Java Communications API, Tillgnglig:

(2008-12-18).

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9 Appendixes

Appendix I: Project plan

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HomeAutomation Report

Documents

Transcript of HomeAutomation Report