The Internet Power Line Adapter - University of Queensland

The Internet Power Line
Adapter
by
Quenten Alick
Department of Computer Science and Electrical Engineering
Thesis submitted for the degree of
Bachelor of Engineering (Hons)
in the division of Computer Systems Engineering
15 th October 1999

Home Automation, Power Lines and the Internet Quenten Alick
The Dean
School of Engineering
University of Queensland
St Lucia, QLD 4072
Dear Professor Simmons,
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57 Primrose Tce
Red Hill QLD 4059
Tel (07) 3369 2749
15 th October 1999
In accordance with the requirements for the degree of Bachelor of Engineering
(Honours) in the division of Computer Systems Engineering, I present the following
thesis titled “The Internet Power Line Adapter”. This thesis was conducted under the
supervision of Dr. Mark Schulz.
I declare that the work submitted in this thesis is my own, except as
acknowledged in the text, footnotes and citations, and has not been previously
submitted for a degree at the University of Queensland nor any other Institution.
Yours Sincerely,
Quenten Alick

Home Automation, Power Lines and the Internet Quenten Alick
Acknowledgments
Many people have contributed to this thesis in one way or another. This is my chance to
thank them.
• Dr Mark Schulz, my supervisor for his consistent advice throughout the year.
• Len Payne for his practical advice and assistance in the thesis labs.
• Tony Truong, my partner, for putting up with me throughout this project.
• John MacDonald, for his assistance with the analogue circuits.
• Montse Ros, for her valuable support throughout the year, and for proofreading this
document.
• To Coiltronics Inc., for their timely provision of some sample inductors.
• And finally, to all my friends, both in and out of the CSE thesis labs, for their
support and good humour through the good and the bad.
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Abstract
Automation systems have been around for many years making light work of
tasks that are considered too menial or dangerous for humans to perform.
Recently there has been a trend towards the development of home automation
systems that will automate many of our tasks around the home, making them
easier to perform and providing humans more time to be creative. However, for
a home automation system to function, different devices must be able to
communicate with each other.
This thesis aims to show that the home’s power lines are suitable for use as a
communications medium for home automation systems. To show this, a power
adapter was designed that would be able to monitor the power consumption of
various devices around the home and let a user monitor it using a web page
interface.
Overall this thesis was successful in demonstrating that the power lines are a
suitable medium for communications within a home automation system despite
there being some problems with the measurement of power. Several
improvements to the design have also been suggested.
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Table of Contents
ACKNOWLEDGMENTS................................................................................................................... II
ABSTRACT.......................................................................................................................................III
LIST OF FIGURES...........................................................................................................................VI
CHAPTER 1 ........................................................................................................................................ 2
1.1 INTRODUCTION......................................................................................................................... 2
1.2 THE DREAM.............................................................................................................................. 2
1.3 GOALS OF POWER LINES & HOME AUTOMATION ....................................................................... 3
1.4 OVERVIEW OF THIS THESIS........................................................................................................ 4
CHAPTER 2 ........................................................................................................................................ 5
2.1 TECHNOLOGY REVIEW.............................................................................................................. 5
2.2 HOME AUTOMATION................................................................................................................. 5
2.2 X-10 POWER LINES HOME AUTOMATION STANDARD................................................................. 6
2.2.1 X-10 Network Layout ...................................................................................................... 6
2.2.2 X-10 Transmission Protocol............................................................................................ 7
2.2.3 X-10 Summary ................................................................................................................ 8
2.3 LONWORKS............................................................................................................................. 9
2.3.1 LONWorks Network Layout & Transmission Protocol ..................................................... 9
2.3.2 LONWorks Summary....................................................................................................... 9
2.4 CEBUS (CONSUMER ELECTRONICS BUS) STANDARD................................................................ 10
2.4.1 CEBus Network Layout ................................................................................................. 10
2.4.2 CEBus Transmission Protocol....................................................................................... 12
2.4.3 CEBus Summary ........................................................................................................... 13
CHAPTER 3 ...................................................................................................................................... 14
3.1 SPECIFICATIONS OF THE SYSTEM ............................................................................................. 14
3.2 OVERVIEW OF THE SYSTEM ..................................................................................................... 14
3.3 CLIENT SPECIFICATIONS.......................................................................................................... 15
3.3.1 Power Measurement & Turn On / Off............................................................................ 15
3.4 SERVER SPECIFICATIONS......................................................................................................... 16
3.4.1 Control and Receive Data from Client........................................................................... 16
3.4.2 Communications with the Internet ................................................................................. 16
3.5 SUMMARY OF SPECIFICATIONS ................................................................................................ 17
CHAPTER 4 ...................................................................................................................................... 18
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4.1 HARDWARE IMPLEMENTATION................................................................................................ 18
4.2 POWER LINES NETWORK CONTROLLER.................................................................................... 18
4.3 POWER MEASUREMENT & SWITCHING..................................................................................... 19
4.4 MICROPROCESSOR .................................................................................................................. 20
4.5 POWER SUPPLY....................................................................................................................... 22
4.6 INTERNET CONNECTIVITY ....................................................................................................... 23
4.7 HARDWARE DESIGN SUMMARY............................................................................................... 23
CHAPTER 5 ...................................................................................................................................... 25
5.1 SOFTWARE IMPLEMENTATION ................................................................................................. 25
5.2 MICROPROCESSOR CODE......................................................................................................... 25
5.3 PC OPERATING SYSTEM.......................................................................................................... 27
5.4 WEB SERVER & PC INTERFACE............................................................................................... 27
5.5 SOFTWARE SUMMARY............................................................................................................. 28
CHAPTER 6 ...................................................................................................................................... 29
6.1 DESIGN EVALUATION.............................................................................................................. 29
6.2 POWER LINES COMMUNICATION EVALUATION......................................................................... 29
CHAPTER 7 ...................................................................................................................................... 32
7.1 REVIEW OF THE DESIGN .......................................................................................................... 32
7.2 FUTURE DIRECTION ................................................................................................................ 33
CHAPTER 8 ...................................................................................................................................... 35
8.1 CONCLUSION .......................................................................................................................... 35
APPENDIX A – SCHEMATICS ....................................................................................................... 36
APPENDIX B – PRINTED CIRCUIT BOARD................................................................................ 40
APPENDIX C – CODE FLOWCHARTS ......................................................................................... 42
APPENDIX D – ASSEMBLER CODE LISTING............................................................................. 44
APPENDIX E – C CODE LISTING ................................................................................................. 50
REFERENCES & BIBLIOGRAPHY ............................................................................................... 61
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List of Figures
Figure 2-1 X-10 transmission signal............................................................................7
Figure 2-2 X-10 Transmission Formats .......................................................................8
Figure 2-3 A TV split into CEBus objects. ................................................................11
Figure 2-4 List of CEBus symbols & Transmission times..........................................12
Figure 2-5 CEBus Power line Chirp ..........................................................................13
Figure 3-1 Block Diagram of the System...................................................................15
Figure 4-1 P300 Evaluation Board ............................................................................19
Figure 4-2 Final Hardware Block Diagram................................................................24
Figure 5-1 Write operation for the P300....................................................................26
Figure 5-2 Software Overview ..................................................................................28
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The Internet Power Line Adapter
Chapter 1
1.1 Introduction
The topics of this thesis, in isolation, hardly need introduction. Today, almost
everyone has heard of and used the Internet in one or more of its forms. It is one
of the fastest growing areas in communications. Likewise, most people
understand the concept of home automation, where computers and machines
control parts of your home. Home automation is often portrayed as being a part
of life in films and shows set in the future. Finally, “power lines” refers to the
power lines within a home that supply power to the home.
1.2 The Dream
If there were no limit on the resources available, the system that had been
envisaged would be a home automation system that could control a wide variety
of different appliances using the power lines as a communications medium. This
overall system would be connected to the Internet and would be able to be
controlled from the Internet, through a web page, by an authorized user.
This system could make a wide variety of possibilities become available. All the
functions of a normal home automation system could be accessed via the
Internet. If you’re at work during a heat wave, you can activate the air
conditioning so that when you arrive home, the house is a comfortable
temperature. Dinner could be cooked and waiting, having been started before
you left work. It also becomes easier to monitor your home while you’re away.
If you left the lights on in the bathroom or left the gas running, you can easily
rectify the situation. You could even remotely control your home security
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systems. Finally, the use of power lines as a communications medium would
greatly reduce the setup cost of such a system since is removes the need for
additional wiring to be installed.
1.3 Goals of Power Lines & Home Automation
Home automation is a very large and diverse field. Almost every modern
appliance could be connected to a home automation system to allow it to
communicate with other appliances and to be controlled from a central point.
With this in mind it was decided to reduce the scope of the home automation
system to the concept of an adapter that any appliance could be plugged into.
This adapter would give a rudimentary measurement of the power consumption
and give the ability to turn the connected appliance on or off.
The Internet is also a very large and diverse field. An entire thesis could be done
on the topic of Internet Security alone. Also, the concept of connecting
appliances to the Internet has been done before and therefore has already been
demonstrated to be feasible. For these reasons it was decided that this thesis
would concentrate on the concept of proving that power lines are a viable
communications medium for home automation systems. The Internet
connectivity would be considered a minor part and would be completed in the
quickest way possible.
The ultimate aim of this thesis is to design a device that will prove that the use
of home power lines as a communication medium for a home automation system
is a realistic option. A device will be designed and constructed in order to prove
this. The exact specifications of this device will be discussed in chapter 3.
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1.4 Overview of this Thesis
The thesis started by introducing the topic with attention to the relevance the
topic has in today’s society. It also presents the vision that this thesis started
with before the dictates of reality reduced its scope. It then presented the goals
of the thesis.
The next chapter is titled the technology review. It takes a detailed look at the
various existing technologies that are used for power line communications
within the home. These technologies are reviewed with attention to their
suitability for use in a new home automation system.
Following this chapter are the specifications for the adapter that will be
constructed. These specifications are taken from a high level. Chapters Four and
Five then look in detail at the hardware and software that was chosen to
implement the adapter, as well as the decisions behind the choices.
Chapter Six describes the results that were obtained from the product and how
they met the design specifications. The following chapter then discusses the
design process with respect to how the student followed engineering practice.
Possible future direction and improvements to the adapter are also discussed in
that Chapter. Lastly Chapter Eight presents the conclusions that were drawn
from this thesis.
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Chapter 2
2.1 Technology Review
This chapter will look at existing technology in the areas of power line
communications and home automation. It is intended to give the reader some
background into the field of home automation. The various existing home
automation communications mediums will be discussed. Following on from this,
several of the existing home automation standards will also be discussed.
2.2 Home Automation
To create a home automation system, various devices within the home must be
able to communicate with each other. As such, the method used to communicate
between devices is very important. To date, many communication methods have
been used, including radio signals, infrared communications and cable, coaxial,
twisted pair and power lines. These methods all have their advantages and
disadvantages.
The wireless communication methods have the advantage of being easier to
install since there is no need to install wires. However, they do have drawbacks.
Radio frequencies suffer from interference from other sources, and infrared
systems require near line-of-sight between receivers in order to function
efficiently. On the other hand, cable systems such as coaxial and twisted pair do
not suffer much interference, but do have the disadvantage of installing the
actual cable. Not only is this expensive in an existing home, it limits the
expansion and changing of a home automation system since new cabling will be
required in order to add new components to the system.
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Power lines communications offers a slightly different set of options to the other
cabling methods. There is no need to install additional cable since every home
has power lines. Outlets are also conveniently placed close to where appliances
will exist in the home. However, power lines communications suffers from
interference problems due to the fact that power is being transmitted as well as
communications, and that the power lines are unshielded and can act like
antennas.
Several standards already exist in the home automation industry and some of
these will be discussed next. The topics that will be discussed are the X-10
power line communications protocol, the LONWorks standard and the CEBus
(Consumer Electronics BUS) home automation standard.
2.2 X-10 Power Lines Home Automation Standard
The X-10 standard is the oldest standard that was considered, being first
introduced in 1978. It is purely a power line communications standard. Due to it
being the first standard on the market it does have widespread support.
However, it originally did not have any support for two-way communication
between devices. Devices capable of two-way communication have only been
developed relatively recently.
2.2.1 X-10 Network Layout
The X-10 network specification allows for up to 256 devices which consists of
16 house codes and 16 unit codes. It also defines X-10 devices as being either
receivers or transmitters. This means that a single transmitter would be able to
control 16 devices. In order to control more devices, new transmitters would
need to be added with each transmitter using a different house code. Receivers
ignore any signal that is not sent to their assigned house code. Two-way
transceivers fit into the same pattern except that they can both receive and
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transmit. In this manner, is should be possible to chain transceivers together to
have a single controller controlling more than 16 devices.
2.2.2 X-10 Transmission Protocol
The X-10 transmission protocol is concerned only with sending pure digital
data. Therefore the only two signals which can be sent are a logical one and a
logical zero. This information is transmitted at the zero crossing point of the
50Hz power signal. Logic one is represented by the presence of a 120kHz PCM
(Pulse Code Modulation) burst 1ms in length at the zero crossing point. Logic
zero is represented by the absence of this burst. Bursts are transmitted three
times per AC cycle to allow the receiver to gather the data even if it is located on
a different phase to the transmitter. The transmission points are highlighted in
figure 2-1. Of course for this to work coupling between phases is required but
devices that can perform this are commercially available.
Transmission points
Figure 2-1 X-10 transmission signal
1ms 120kHz burst
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A complete X-10 takes 11 AC cycles to transmit. The header code (1110) is
transmitted during the first two AC cycles with one bit transmitted per half
cycle. The next eight cycles are used to transmit eight data bits, with each bit
being transmitted both “normally” and complemented. This is similar to
Manchester Encoding and is used to make to signal more resistant to line noise.
The first four bits are the house code and the second four are the unit code.
Finally, a stop bit is transmitted in the 11 th AC cycle.
Once the 11-cycle transmission has been completed, the transmitter goes idle for
at least three AC cycles before it repeats the same transmission. After the repeat
transmission, a signal can be sent that will tell the addressed device what it has
to do, for example for a light, turn on or off. This message must also be
transmitted twice. The formats of the two messages are shown in figure 2-2.
Start code (4 bits) House code (4 bits) Unit code (4 bits) Stop bit (1 bit)
Start Code (4 bits) House Code (4 bits) Control (4 bits) Stop bit (1 bit)
2.2.3 X-10 Summary
Figure 2-2 X-10 Transmission Formats
Although the X-10 system is widely used and already has many products on the
market, there is one main drawback to the system. Despite all the redundancy in
the transmission of information, the signal is still very susceptible to line noise. In
many cases, repeaters or noise blocks / filters (to remove the effects of high
capacitance power loads such as computers) need to be added before the home
automation system functions reliably.
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2.3 LONWorks
LONWorks is an automation standard that was developed by Echelon. It was
originally used in industrial automation areas but has since moved towards the
home automation market. The standard is defined so that any medium can be
used to transit signals. LONWorks is intended as a complete solution that
provides all the necessary parts for a home automation system.
2.3.1 LONWorks Network Layout & Transmission Protocol
LONWorks uses a network where a central controller or a master / slave
network is not needed. Instead there are local control nodes that are responsible
for controlling a certain groups of sensors or actuators.
The LONWorks transmission protocol is called LONTalk. This is a standard
which unfortunately costs about $150US to purchase. Due to this reason, it was
not possible to review the LONTalk standard in any depth. However, the
standard does cover the seven layers of the OSI network model. It also provides
the facilities necessary to implement a secure network, such as transaction
acknowledgement, peer to peer communications and error detection and
recovery.
2.3.2 LONWorks Summary
One of the main problems with the LONWorks standard is the cost of getting the
technical details and the development tools. When compared to the cost of
purchasing the equivalent parts from CEBus, LONWorks proved to be much
more expensive. However, this appears to be the only real drawback of the
system. LONWorks has been used extensively in industry for many years with a
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recent move being towards home automation networks. It will be interesting to
see how this standard fares in the next few years.
2.4 CEBus (Consumer Electronics Bus) Standard
The CEBus standard is designed as a general standard for home automation.
Like the LONWorks standard, CEBus does not specify any one communications
medium, rather it lays out specifications for using any of the mediums, either in
isolation or in combination, that can provide home automations services. The
mediums supported by the CEBus standard include power line wiring, infrared,
radio frequency, twisted pair cables and coaxial cables.
2.4.1 CEBus Network Layout
CEBus has two possible methods of organization and control. Either all nodes in
the network are independent and can communicate and control each other, or a
“cluster control” node can control several other nodes. These two methods can
also be combined in the one network. In this way, CEBus does not require a
central control point; neither does it exclude the possibility.
Each device on a CEBus network has two addresses. The first is the house code
which is shared by all devices in an area such an apartment or home. The second
is a device address that is unique to each device. There is provision for about
64k (2 16 ) unique devices for each house code, which also has 64k values.
Several of these are reserved, such as the broadcast address.
Every network also has a control channel and an optional number of data
channels. The control channel is used to send command messages in a specified
format and is required by all CEBus compliant nodes. The data channels are
used to send other information, which can be in any format desired. The only
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restriction is the frequency and amplitude limitations of the channel on the
medium.
Various services are built into the CEBus standard. These include the options for
acknowledged “handshake” style services, unacknowledged services, parity
checks and packet priority as well as sequence numbers. This means that the
CEBus standard can be implemented as a reliable network or an unreliable
network. Finally, there is also provision for authentication information, which
can be used to implement security features.
To make it possible for different CEBus compliant devices from different
vendors to communicate with each other within a home, many common home
automation appliances and their functions have been predefined as CEBus
objects. See figure 2-3 for an example of how a TV can be broken into CEBus
objects. This means the CEBus controllers can broadcast onto the network, find
devices and query them to find out what they are capable of by sending a certain
predefined request. The device can then respond saying that it is capable of
certain standard functions that the controller will know how to control since
they’ve already been defined. This means that CEBus standard can create a Plug
and Play network.
Figure 2-3 A TV split into CEBus objects.
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2.4.2 CEBus Transmission Protocol
The CEBus standard does not define exactly how each medium should represent
data. It defines that the transmission medium should be capable of taking on two
different states, superior and inferior. The inferior state is defined as the idle
state of the medium. To begin making a transmission, the medium starts in the
superior state. It then alternates states for each successive symbol that is
transmitted.
The length that each state is transmitted for indicates which symbol is being
transmitted. There are four different symbols, logical one, logical zero, end-of-
field and end-of-packet. The transmission lengths and symbols are summarized
in figure 2-4.
Symbol Name Transmission Length
Logical One 100μs
Logical Zero 200μs
End-of-Field 300μs
End-of-Packet 400μs
Figure 2-4 List of CEBus symbols & Transmission times
In the case of power line CEBus products, the superior state is defined as a
“chirp” of noise which is transmitted at the zero crossing point of the 50Hz AC
power signal. The “chirp” is defined as a signal that changes frequency from
200kHz to 400kHz, then 100kHz to 200kHz within the space of 100μs. The
spread-spectrum chirp is shown in figure 2-5. In order to create the different
length states for the different symbols, this 100μs chirp is repeated to create the
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required length symbol. Finally, the frequency sweep means that the “chirp” is
spread-spectrum, which gives the “chirp” better noise resistance.
Figure 2-5 CEBus Power line Chirp
All data in the CEBus protocol is transmitted in packets with a header and a
“payload” or message. The header contains information on the type of service
being provided as well as source and destination addresses with the total length
being around nine bytes. The packet message can be up to 32 bytes long and can
contain any data that the recipient understands.
2.4.3 CEBus Summary
The CEBus standard has several advantages. Firstly it allows for a large number
of appliances within a home. While sixty-four thousand per house code may be a
little excessive, it is many more than the sixteen that the X-10 standard offers.
Secondly, the open and versatile nature of the CEBus standard that allows
different vendors to create a device and be reasonably certain that it will be able
to communicate with the device from another vendor. Thirdly, the spread-
spectrum nature of the power line implementation means that the system has
quite good noise immunity. Finally, the way in which the network can be set up
to suit the needs of the user is extremely versatile. Both reliable and unreliable
networks can be created using the CEBus standard. These factors mean that the
CEBus standard was the choice made for the power line communications
standard in this thesis.
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Chapter 3
3.1 Specifications of the System
This chapter will outline the specifications for the device that will be designed to
meet the goals that were defined earlier. The various sub-sections of this design
will be examined to determine what requirements each section needs to be meet
to achieve the goal.
3.2 Overview of the System
To prove the use of power lines communications as a realistic option for home
automation a simple client / server device will be designed. The client part of
this device will be an adapter to which any normal household appliance can be
connected. The adapter will be able to measure the power that is consumed by
the attached appliance. It will also be able to turn off the appliance. This would
give a user the ability to monitor the power consumption of their home and to
adjust it to suit their needs. The server device will be responsible for controlling
the client device and receiving data from the client. It will also be connected to
the Internet. See figure 3-1 for an overall layout of the system
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Adapter 1
Internet
Controller&
Web Server
Figure 3-1 Block Diagram of the System
3.3 Client Specifications
3.3.1 Power Measurement & Turn On / Off
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Adapter 2
The accurate measurement of power consumed in home AC systems is a very
large and difficult topic. For this thesis, the emphasis is on the home automation
system, not the power consumption, therefore the power meter will not be
designed to be accurate. It is intended more for the purpose of generating some
meaningful data that can be sent across the power lines. Therefore the main
requirement for the power meter is that it is simple and easy to build.
The ability to turn the connected appliance on or off is also intended to prove the
communications aspect. It is quite a simple feature to implement but it is typical
of the type of communications that needs to be sent to simple home automation
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3.4 Server Specifications
3.4.1 Control and Receive Data from Client
In order to control and receive data from the client, the power line
communications medium will be used. The main requirement for this is
simplicity and low cost. There is no need for a high-speed link since the adapter
being designed relies on human input. In this case a response time of a second
would be quite acceptable. Also, the amount of data being transferred from the
client to the server is relatively small. Reliability is also not essential. Although
a reliable communications link is desirable, the nature of the data being
transmitted means that loss of data or corrupted data will not adversely affect the
system.
3.4.2 Communications with the Internet
There are many options that need to be considered when connecting a device to
the Internet. For a practical home automation system, the use of a modem is
likely to be the best option. However, as was mentioned earlier, the Internet
Connectivity of this design is not considered to be the main focus of the thesis.
For this reason, the only requirement for the Internet connection is that it be
quick and simple to set up.
To be able to remotely control the adapter the controller in the system will need
to have a web server. The requirement for this is the ability to handle incoming
requests as well as being able to update a local web page to reflect the current
status of the system.
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3.5 Summary of Specifications
This chapter has outlined the general specifications for the adapter that are listed
below. The next chapter will take a thorough look at the possible specific
hardware solutions that will address the listed specifications.
Adapter Specifications
� Client:
� Measure Power Consumption
� Turn Appliance On / Off
� Receive data from Server
� Server:
� Control Client
� Receive data from Client
� Communicate with the Internet
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Chapter 4
4.1 Hardware Implementation
This chapter will look at the hardware design decisions that were made for the
adapter. The design decisions will be examined with reference to the
specifications mentioned in the previous chapter.
4.2 Power Lines Network Controller
It had already been decided to use a CEBus compatible power lines network
controller. Of the companies that offered CEBus compatible network chips, the
Intellon and Domosys chips seemed to be the most suited. With the only
requirement that the system be simple, the main determining factor became the
cost of purchasing a development kit.
In the end, the Intellon P300 kit proved to be the most suitable. It was the
cheapest solution available that provided two development boards with the
provision for the use of either a MC68HC05 microprocessor or another
alternative microprocessor. The alternative Domosys development board had the
option of either a combined microprocessor with network chip or a standalone
network chip. However, both these options also required the further purchase of
a circuit to interface the chip to the power lines. With the Intellon boards, the
power line interface circuitry, network controller and microprocessor were all in
the same development kit. This made the Intellon board cheaper.
The P300 development kit made use of three separate chips. See figure 4-1 for a
picture of the development board. These were the microprocessor, a
MC68HC705C9, the P300 power line network controller and the P111 media
interface IC. The P300 chip takes information from the microprocessor and
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converts it into a CEBus compliant analogue signal. This output signal is in the
form of the chirps mentioned earlier. However, it is not possible to directly
couple this signal to the power line power signal. It must first be filtered and
amplified before it can be coupled. The P111 is responsible for the amplification
of the output signal. Discrete components are used to filter the input from the
P300 to the P111 as well as the signal from the power line, which is sent directly
to the P300.
Figure 4-1 P300 Evaluation Board
4.3 Power Measurement & Switching
Proper measurement of power for an appliance can be a difficult proposition. An
entire thesis could be written on the topic of accurate power measurements itself.
For this reason, a relatively simple circuit was designed to measure the power
consumed by the appliance connected to the adapter.
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The basis of the circuit is the measurement of current. Since the adapter is
plugged into the main supply, it is reasonable to expect that the supply voltage
will be a constant 240V AC. If the current can be measured then by sampling the
current and averaging over a time period, then using the result in a simple
“power equals voltage times current” equation, a rough measure of the power
should be attained.
The main concern with this circuit is choosing a suitable series resister that is
able to dissipate the power that may run through it.. For this, a 0.1Ohm 7-Watt
power resister can be placed in series with the load i.e. the appliance. As a
precautionary measure, a 5A fuse should be placed in series with the appliance.
The voltage across the power resister can then be passed to a low pass filter to
remove line transients and noise. The chosen filter was a Sallen-Key 2 nd order
active filter with a cut-off point of 100Hz [4]. This should be sufficient to retain
the power signal while removing most of the transients.
The output from the filter can then be passed to a simple Op Amp circuit to
achieve a gain that will distribute the resulting voltage across the 5V range of
the ADCs used on the microprocessor. Finally, the switching of the adapter can
be accomplished relatively simply using a relay. A dry reed relay that switches
240V AC using a 5V input was selected. This relay needs to be placed in series
with the appliance.
4.4 Microprocessor
The microprocessor used for both the client and server must be capable of
controlling the power lines network chip. As mentioned before, there is no need
for fast communications. Therefore, the processor need not be fast and an 8-bit
microprocessor should be sufficient. For the client, there is an additional need
for Analogue to Digital Converters (ADCs) in order to translate an analogue
signal from the power meter into a digital signal. It is possible to use external
ADCs so this requirement will serve to mainly save board space.
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Home Automation, Power Lines and the Internet Quenten Alick
The chosen microprocessor must also have both an SPI (Serial Peripheral
Interface) and an SCI (Serial Communications Interface). The SPI is needed to
be able to communicate with the Intellon P300 network chip and the SCI
interface is needed to communicate with the PC that will be running the web
server. In order for the SCI interface to be able to communicate with the PC a
RS232 transceiver must be used to convert the voltage levels from TTL to
RS232 and vice versa. The MAXIM MAX232 RS232 interface should be able to
perform this task with a minimum of extra circuitry.
There are a number of processors from the Motorolla range that are suitable. The
processors considered were from the MC68HC05 and the MC68HC11 range.
The use of a MC60HC05C series would have been ideal since the Intellon
development board already used one. The only drawback would have been the
need to provide external ADCs since the MC68HC05C does not provide any
internal ones. This would require more PCB space, making the board more
expensive. However, the cost of purchasing another development kit for the
microprocessor made this option non-feasible. Even if a development kit could
have been found, the individual cost of $55 per microprocessor was also rather
high. If this option had been taken, the cost would have risen about $310.
This left the choice with the various MC68HC11 processors for which there
were suitable development kits available. The microprocessor used in the
development kits was the MC68HC11A1. This is an 8-bit processor with ADCs
and a SPI and SCI interface and so meets the requirements. The 256 bytes of
RAM should be sufficient to store temporary variables, however the 512 bytes
of EEPROM are insufficient to store data from the power meter.
There are several options available to address this problem. Firstly, the
MC68HC11A1 development boards come with 8k of parallel SRAM, which is
more than sufficient to store the required data. If necessary, the system could be
demonstrated using the development boards. The preferred option would be to
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Home Automation, Power Lines and the Internet Quenten Alick
add some external EEPROM to the microprocessor. One option for this would
be the Microchip 25C080 serial EEPROM which contains 8k of EEPROM,
arranged as 1024 x 8.
This EEPROM uses an SPI interface. Although this could be connected to the
SPI interface on the microprocessor, it is preferred that this SPI be devoted to
communicating with the P300. Port pins can still be used to access serial
EEPROM by “bit-banging” the interface. The final fallback is to use a
MC68HC11E2 microprocessor without the serial EEPROM. The MC68HC11E2
is identical to the MC68HC11A1 except that it has 2048 bytes of EEPROM. The
drawback is that the recording time for the power meter will have to be reduced.
4.5 Power Supply
The power supply for the client and server was relatively straightforward. The
Intellon PIII interface chip requires a 10V DC supply and the microprocessor
and the P300 network chip require 5V DC supplies. These are the only two
requirements of the power supply. Since both the adapter and the controller need
to be plugged into the 240V AC mains supply for the communications, this also
provides a simple way of powering the two devices.
The Intellon development boards required the use of a separate wall adapter that
stepped the 240V AC mains supply down to 12V AC. From this supply, a diode
bridge and capacitor were used to rectify the AC signal to a DC one. From here,
two voltage regulators were used. The first was an LM2940T-10, which gives
10V from 14-16V. From the 10V supply a LM7805 voltage regulator was used
to provide the 5V supply. These regulators can supply sufficient power for the
circuitry.
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Home Automation, Power Lines and the Internet Quenten Alick
4.6 Internet Connectivity
As has been mentioned before, the main aim of the Internet Connectivity was for
ease and simplicity. Several options were available and they included using an
Ethernet Controller with an embedded microprocessor, using a Modem chip
with an embedded microprocessor or using a PC with an existing operating
system and web server. The latter choice of PC was chosen since it represented
the quickest and easiest way of connecting to the Internet. Another benefit of
this is that the same microprocessor can be used for both the client and the
server.
The PC used in the thesis was built from spare parts. Any processor greater than
an 80386 would have been suitable. A hard drive and a network card were the
only other hardware components required apart from user input / output
components. The network card was needed to connect to the Internet via an
Ethernet connection. One advantage of the PC is that it is capable of running
several types of software that could be used for Internet connectivity such as
DOS or Linux. The software used on the PC will be discussed in the next
chapter.
4.7 Hardware Design Summary
This chapter has investigated the various hardware design decisions that have
been made. The power line communications chip meets the requirements of
being both cheap and simple to implement. Likewise the microprocessor meets
similar requirements as well as the requirement of having SCI and SPI interfaces
for communications and ADCs for measuring the power. The choice of using a
PC for the Internet connectivity meets the requirements of being simple to
implement and also means that the same microprocessor can be used for the
client and the server, which will make the design simpler. In the next chapter the
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Home Automation, Power Lines and the Internet Quenten Alick
specific software requirements of the thesis will be discussed. See figure 4-2 for
a detailed overview of the system.
Internet
PC
MC68HC11
P300 &
P111
- 24 -
Power
Module
Server Client
Power
Lines
MC68HC11
P300 &
P111
Figure 4-2 Final Hardware Block Diagram

Home Automation, Power Lines and the Internet Quenten Alick
Chapter 5
5.1 Software Implementation
This chapter will look at the software design issues that were considered for the
system. These design decisions will be looked at with reference to the
specifications in chapter three and the restrictions imposed by the hardware
chosen in chapter four.
5.2 Microprocessor Code
The first task that the code in both the client and server microprocessor must
complete is the communications with the P300 network chip. These
communications require the use of the SPI interface on the microprocessor. The
format for data that is being sent to the P300 is a command byte, and length byte
then zero or more bytes of data. A similar format is used for reading data from
the P300. Firstly a command byte is sent by the microprocessor. Then the P300
returns a length byte followed by the specified amount of data bytes.
An interrupt driven transmission is the easiest way to transmit the data. In this
format, the main body of the code initiates the transmission. Once the
transmission has started, the SPI interrupt code in the microprocessor completes
the rest of the transmission. The flowchart in figure 5-1 demonstrates the write
operation [15]. The read operation is very similar to this. The main difference is
that the microprocessor must feed in dummy data to generate a clock signal for
the P300 to transmit its data out on.
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Home Automation, Power Lines and the Internet Quenten Alick
Figure 5-1 Write operation for the P300
The server microprocessor also has to communicate with the PC through the SCI
interface. Since the server microprocessor has no other functions to perform, it
was decided to make the microprocessor appear transparent to the PC.
Therefore, the same format for data transmission was used in the SCI code. In
this way, the majority of the computation can be done on the PC, which has
more resources than the microprocessor.
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Home Automation, Power Lines and the Internet Quenten Alick
The client microprocessor must collect data from the power measurement
circuitry. An ADC on the microprocessor will be used to collect this data by
sampling the output from the power measurement circuit at a rate of 100Hz.
These samples will then averaged over a minute and the result will then be sent
to the server. The sample rate of 100Hz, sixty samples and one byte per sample
gives 6k bytes storage required.
5.3 PC Operating System
The choice of operating system for the PC needed to be made between DOS,
Windows9x and Linux. Windows9x was discounted almost immediately due to
the added complexity of programming in the visual environment. Also, network
and TCP/IP programming under windows is much more difficult due to the
Microsoft implementation of TCP/IP. This left the choice between DOS and
Linux.
Of these two, Linux was deemed to be a more suitable choice. Linux is a multi-
tasking operating system, which lends itself better to the use of a web server. It
also has built-in TCP/IP support that DOS does not have. Finally, there are
embedded versions of Linux, such as ELKS, which could be used to port
software with a minimum of fuss should this system be converted to use an
embedded processor.
5.4 Web Server & PC Interface
The PC interface to the microprocessor is fairly simple. It consists of setting up
the serial port correctly then transmitting data in the format specified for the
P300 network chip. The actual interface does not need to perform many
operations, just to turn the adapter on or off and to read a power value back from
the client. A short program will be written to perform each of these operations.
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Home Automation, Power Lines and the Internet Quenten Alick
These programs will be initiated by a Perl CGI script, which will be linked to the
web page. By using links of the web page, the script will be invoked with
different parameters, which will call the different interface programs. The web
server will be responsible for invoking the CGI scripts when the web page links
are followed. The web server that was chosen for this thesis is the Linux Apache
web server. This is a very popular web server that includes support for CGI
scripts.
5.5 Software Summary
This chapter has looked at the various software design decisions that were made.
These decisions have been made on the basis of the hardware that has been
chosen. An overview of how the software fits together is given in figure 5-2.
The next chapter will look at the design evaluation of the thesis.
Web
Server
CGI
Script
Control
Code
- 28 -
SCI
Interface
SPI
Interface
Power
Measurement
Code
SPI
Interface
Server Client
Figure 5-2 Software Overview

Home Automation, Power Lines and the Internet Quenten Alick
Chapter 6
6.1 Design Evaluation
This chapter will be an evaluation of the design and will look at whether the
design met the specifications or not. After this the actual performance of the
power line communication will be evaluated.
The overall specification was to create a system that would prove that power line
communications is a viable medium for communications in a home automation
system. The further specifications for the system were that the client be a power
adapter with the ability to be switched on and off with a server that was
connected to the Internet and could control the client.
These objectives were partially met. The connection to the Internet was
successful and functions as expected. Also, the power measurement circuit will
function as intended, which is to say that the results are inaccurate but accuracy
was never a requirement. However, the other parts of the server do not work as
expected. The problem lies in the communications between the microprocessors
and the P300 network interface chip. However, it is hoped that in the next two
weeks that these problems will be solved.
6.2 Power Lines Communication Evaluation
An evaluation of the power line communication chip could be carried out using
the development boards. This evaluation looked at aspects of the system such as
reliability, data rates and noise / load immunity.
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Home Automation, Power Lines and the Internet Quenten Alick
The data rates achieved by the development boards were close to 9600 bits per
second. This figure matches fairly closely with the specifications for the CEBus
standard, which states that all command channel data should be transmitted at
10k bits per second regardless of medium.
The reliability and noise / load immunity all relate to each other. Generally, the
noise immunity was good. The testing was conducted in the Axon building,
which has many pieces of electrical equipment & computers in use at one time.
In tests it was found that the boards could communicate well across the entire
building provided that they were on the same power phase. Overall, while on the
same phase the boards achieved close to perfect data transmission.
However, when a computer was plugged into the power lines between the two
boards, the performance decreased. Computers are a special problem due to the
large capacitance in their power supply. This capacitance tends to filter out the
communications signal. When the boards used unacknowledged signals, the
reliability of transmission dropped to almost zero. However, when the boards
used the acknowledged modes, the reliability of transmission only dropped to
80-90%. This shows that using the more reliable modes, although slower, are
much more effective even when large loads are being used in the circuit.
The last sets of tests were conducted with the boards attempting to communicate
across the different power phases in the building. The results from these tests
indicated low reliability. However, it is impressive that there was any
communication at all since the phases in the building are not directly coupled.
Since some homes will use different phases for different parts of the house, it is
important that power line communications for home automation systems must
be able to communicate across phases. The normal solution for this is to directly
couple the phases. This can be done with some commercially available devices,
or more simply, a correctly rated capacitor can be connected across the two
phases. This is usually sufficient to allow communication to occur.
Unfortunately, we were unable to test this.
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Home Automation, Power Lines and the Internet Quenten Alick
The next chapter will review the design and the design process. It will also look
at what improvements could be made to this design in the future.
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Home Automation, Power Lines and the Internet Quenten Alick
Chapter 7
7.1 Review of the Design
This chapter will be looking at the design of the system, with the benefit of
hindsight, and how the design was carried out. The three main sub-sections of
the system will be examined, the power measurement unit, the Internet
connectivity and the power line communications.
Overall, the biggest problem that was encountered with the design was defining
the topic. Linked with this problem was the original scope of the topic as well.
Initially there was a grand plan as to what could be accomplished and it was not
realized until too late, that the plan was not feasible to implement in the
timeframe available. As a result, time was wasted on areas that have not been
included in the final product. This is a problem with the way that the thesis was
approached by the students, and as (soon-to-be) professional engineers, it is an
area upon which they need to improve.
The areas that were approached ambitiously were that of the Internet
connectivity and the power measurement. Part of the original plan was to use an
embedded web server to connect to the Internet. This was chosen since an
embedded processor is much cheaper than a PC (the option that we took in the
end). Embedding the web server also has the advantage that the device is
dedicated and can devote all its time to servicing requests whereas a PC will
often be used for other applications. Although most homes have PCs these days
it is unlikely that most home automation users would be able to install and use
Linux and Apache. The final advantage of the embedded system is that it is
much more portable than a PC.
The power measurement also started as part of the grand plan that needed to be
cut back. The design of accurate watt-hour meters is a complex topic that can be
- 32 -

Home Automation, Power Lines and the Internet Quenten Alick
an entire thesis topic in itself, according to one of the department’s lecturers. It
is also an area much more suited to design by a power or electrical engineering
student, rather than a computer systems engineering student. Even when the
topic was reduced to a simple meter that was not accurate, the full implications
of designing an interface to the mains supply did not sink in. Resistors only
come with power ratings up to a certain value and so what may have been
feasible for low voltages rapidly become non-feasible for larger voltages.
The end result of this is that more time should and could have been spent
working on the main focus of this thesis, which is the power line
communications. If the topic had been defined earlier and more clearly, then this
thesis would have been completed in a much more efficient manner.
7.2 Future Direction
The future direction that this thesis could take is self-evident. Moving back to
the original plan would realize a product much more suitable for use in a modern
home automation system. With an embedded web server the entire server end of
the system could control and monitor many adapters around the home, all of
which would gather information about the power consumption within a home.
Then either the server itself or an external user could make decisions about
which appliances to run depending upon their power consumption.
This step would involve changing the microprocessor at least in the server. A
suitable processor for the web server would probably be 32 bit with 4Mb of
external RAM. This should be sufficient to run ELKS or a similar operating
system. Then all that is needed is dedicated web server code to handle the HTTP
requests and some code to control the client via the power line communications
network chip. The options to connect the web server are either an Ethernet link
or a modem. Considering that most homes these days do not have an Ethernet
Internet connection, the use of a modem is probably the better choice.
- 33 -

Home Automation, Power Lines and the Internet Quenten Alick
Internet security was not looked at in this thesis and this is an important area for
any physical device attached to the Internet. An implementation of security so
that only authorized users can access the house is essential for any commercial
home automation product.
At the other end of the system, the power module could benefit from a much
more accurate design. With an accurate power module, this system could be a
valuable addition to a home automation system even without the Internet
connectivity. For accuracy, the power module should account for the effects of
reactive loads for accurate measurements as the current module only measures
the apparent power.
- 34 -

Home Automation, Power Lines and the Internet Quenten Alick
Chapter 8
8.1 Conclusion
The overall aim of this thesis was to prove that power lines are a feasible
medium through which home automation systems can communicate. The
method of proving this was to design and construct a simple home automation
system that measured the power consumed by an appliance attached to the
system. This system used a client and a server to communicate across the power
lines and exchange information.
Overall, this thesis accomplished some of its aims. Although the primary aim of
proving the power line medium was accomplished, the complete design of the
adapter was not. Problems encountered with the power measurement unit were
the main obstacle to the completion of the design.
However, power lines were successfully demonstrated to be a viable medium for
communicating within a home automation system, when faced with electrical
conditions not normally found within the average home. The ease of installation
and the reliability of the system show that the power lines are probably the most
cost efficient method of communicating within a house.
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Home Automation, Power Lines and the Internet Quenten Alick
Appendix A – Schematics
development board
newbrd.sc1
+5V +5V SW_BOT
SW_BOT +5V
+5V
GND
SW_TOP
MODE
E_SO
P_INT*
RXD
MISO
P_RST*
P_CS*
LED_RED
LED_GRN
E_CS*
E_SI
E_SCK
TXD
MOSI
SCK
Modification to Development Board
- 36 -
additional circuitry
other.sc2
SW_TOP
MODE
E_SO
P_INT*
RXD
MISO
P_RST*
P_CS*
LED_RED
LED_GRN
E_CS*
E_SI
E_SCK
TXD
MOSI
SCK
GND

Wall Module
POWER
SW3
J1
1 12 VAC
VAA
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
2
3
Neutral
C7
1.0UFX
C18
1.0UFX
ALTERNATE HOST
J2
+5V
20 PIN
USER I/O
D15
P6KE10A
D16
P6KE10A
B_MODE
B_TOP
B_LOAD
B_BOTTOM
E_CS*
E_SO
E_SI
E_SCK
P_4MHZ
P_CS*
P_INT*
P_SCLK
P_SDO
P_SDI
P_RST*
P_RST*
P_CS*
LED_RED
LED_GRN
E_CS*
E_SI
E_SCK
1 2
P_RST*
P_CS*
B_LOAD
B_MODE
E_CS*
E_SI
E_SCK
1
2
L3
820 UH
3 4
VAA
R20
180
TP5 (NI)
1
2
D13
1N5819
T1
12:12
20000392
F1
FUSE
JP2
BUSS WIRE
L1
1.8UH NLC
D6
1N5819
VAA
R4
1K
VAA
D1
1N4002
R6
10K
D2
1N4002
C38
2200UF,25V
C2
0.1UFZ
LED2 D10
R7 LED1
LN31GPHL
10K
(GREEN)
SW2
TXD
MOSI
SCK
C34
.01UFX
JP3
BUSS WIRE
Q1
MMBT3904
TXD
P_SDI
P_SCLK
L5
120UH
D3
1N4002
1
2
3
4
5
6
7
8
D4
1N4002
U5 SSC_P111
VSS
VDD
VSS
TXO
VSS
VDD
TP0
TS
C27
0.1UFZ
L4
180UH
C36
3300PFX
+5V
PB
NC
VSS
NC
CEXT
NC
BIAS
VDD
TXI
+5V
16
15
14
13
12
11
10
9
C35
3300PFX
C37
1500PFX
P_INT*
P_INT*
E_SO
E_SO
B_BOTTOM
SW_BOT
B_TOP
SW_TOP
MODE_JMPR
MODE
RXD
RXD
P_SDO
MISO
C28
22UF,25V
D8
NEWBAV99
C20
3300PFX
1
C23
0.1UFZ
U4
LM2940T-10
Vin
C26
1.0UFX
D5
GND
2
R1
510
NEWBAS16
R26
1.2K
Vout
3
L2
180UH
VAA
TRADE SECRETS
THIS DRAWING AND ITS CONTENTS ARE TRADE SECRETS AND
CONFIDENTIAL BUSINESS INFORMATION OF INTELLON CORPORATION
1
U1
LM7805C
HEAT SINK
C3
0.1UFZ
R22
1K
HEAT SINK
C19
470UF,16V
D12
LN31GPHL
(GREEN)
VAA
R16
75K
1%
+5A
R5
1K
R27
18K
C25
1500PFX
R24
47
D11
LN21RPHL
(RED)
R9
10K
Q2
MMBT3904
+5A
R29
1K
Q3
MMBT3904
C22
3300PFX
Q4
MMBT3904
JP1
MON
TP1 (NI)
POWER
SW1
Vin
R2
13K
AND ARE NOT TO BE USED OR DISCLOSED FOR ANY PURPOSE WITHOUT
THE PRIOR WRITTEN PERMISION OF AN OFFICER OF INTELLON CORPORATION.
PB
VAA
R19
100
+5V
GND
2
R13
10K
R10
10K
C21
3300PFX
NOTE 1: MODEL EB P200: U2 = SSC P200 IC (10000662)
MODEL EB P300: U2 = SSC P300 IC (10000739)
Original Development board Schematic with Modifications
+5V
GND
3
2
1
Vout
3
C9
220PFC
C1
0.1UFZ
R3
1K
+5V
1
P_INT* 2
3
4
R12
10K
P_CS*
P_RST*
5
6
MODE_JMPR 7
8
B_BOTTOM 9
B_LOAD 10
B_TOP 11
B_MODE 12
MTG
MTG
TP4 (NI)
M1
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
13
14
15
16
17
18
19
20
21
22
C15
33PFC
C14
33PFC
C8
0.1UFZ
C5
0.1UFZ
RST*
IRQ*
NC
NC
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
PB0
PB1
PB2
PB3
NC
PB4
PB5
PB6
PB7
VSS
C13
470UF,10V
+5V
Y1
12 MHz
NEWBAS16 R15
100K
VDD
OSC1
OSC2
TCAP
PD7
NC
TCMP
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
NC
U3 MC68HC705C9A (NI)
MOUNTING HOLES
M2
M3
M4
M5
D7
R14
1M
C4
0.1UFZ
31
30
29
28
27
26
25
24
23
C10
0.1UFZ
+5V
CONTRACT NO:
APPROVALS DATE
CHECKED:
ENGINEERING:
MANUFACTURING:
10
USED ON NEXT ASSY
1
2
3
4
5
6
7
8
9
C29
0.1UFZ
C12
C30
44
100PFC
+5V
0.1UFZ
43
42
41
40
39
P_4MHZ
TP3 (NI)
TCAP
R28
10K
C31
0.1UFZ
TP2 (NI)
38 TCMP TCMP
37
PD5/SS*
36 P_SCLK
PD4/SCK
35 P_SDI
PD3/MOSI
34 P_SDO
PD2/MISO
33 TXD
PD1/TDO
32 RXD
PD0/RDI
M6
R17
10
PC2
PC3
E_CS*
E_SO
E_SI
E_SCK
R25
100
R18
0 OHM
R21
100K
REVISIONS
REV ZONE DESCRIPTION APPROVAL DATE
4
ECO #1299
U2 SEE NOTE 1
4MHZ
CS*
VSSD
XIN
XOUT
VDDD
INT*
SCLK
SDO
SDI
+5V
1
CS* VCC
2
SO HLD*
3
WP* SCK
4
VSS SI
8
7
6
5
1
2
3
4
5
6
7
8
VSSD
TP0
VDDA
SI
C1
C2
SO
VSSA
RST*
TS
20
19
18
17
16
15
14
13
12
11
C32
0.1UFZ
U6 MAX232
16
C1+ VCC
15
V+ GND
14
C1- T1OUT
13
C2+ R1IN
12
C2- R1OUT
11
V-
T1IN
10
T2OUT T2IN
9
R2IN R2OUT
RS-232
U7 25C080 R11
10K
EEPROM
Error : LOGO.WMF file not found.
+5V
R8
10K
C6
0.1UFZ
C17
680PFX
C33
1.0UFX
+5A
C11
0.1UFZ
C16
680PFX
INTELLON CORPORATION
5100 WEST SILVER SPRINGS BLVD.
OCALA, FL 34482
TITLE:
SCHEMATIC
EB P200/EB P300 EVALUATION BOARD
SIZE
B
NUMBER:
60000682
REV:
4
PRINT DATE: 13-Oct-1999
SHEET: 1 OF 1
FILE: C:\Thesis\..\newbrd.sc1 DRAWN: G. LASBY
+5V
C39
R30
33
100UF,16V
RX
RTS
TX
CTS
GND
J3
DB9
1
6
2
7
3
8
4
9
5

Home Automation, Power Lines and the Internet Quenten Alick
- 38 -
MODA/LIR
3
PA3/OC5/OC1
31
PA7/PAI/OC1
27
PC0/AD0
9
PC1/AD1
10
PC2/AD2
11
PC3/AD3
12
PC4/AD4
13
PC5/AD5
14
PC6/AD6
15
PC7/AD7
16
PD0/RXD
20
PD1/TXD
21
PD2/MISO
22
PD3/MOSI
23
PD4/SCK
24
PD5/SS
25
RST
17
STRA/AS
4
IRQ
19
EXTAL
7
MODB/VSTBY
2
PA0/IC3
34
PA1/C2
33
PA2/C1
32
PE0/AN0
43
PE1/AN1
45
PE2/AN2
47
PE3/AN3
49
PE4/AN4
44
PE5/AN5
46
PE6/AN6
48
PE7/AN7
50
VRH
52
VRL
51
XIRQ/VPP
18
E
5
PA4/OC4/OC1
30
PA5/OC3/OC1
29
PA6/OC2/OC1
28
PB0/A8
42
PB1/A9
41
PB2/A10
40
PB3/A11
39
PB4/A12
38
PB5/A13
37
PB6/A14
36
PB7/A15
35
STRB/R/W
6
XTAL
8
Vss
1
Vdd
26
UN1
MC68HC11E2(52)
+5v
SW_BOT
SW_TOP
MODE
E_SO
GND
+5V
SW_BOT
SW_TOP
MODE
E_SO
+
CN1
4.7uF_pol
CN2
0.1uF
+5V
+5V
XN1
8Mhz
RN1
10M
CN4
~18pF
CN3
~18pF
RN2
4.7k
RN3
4.7k
+5V
RN4
1k
C5
1uF
IN
2
RSET
1
GND
3
UN2
MC34064
+5V
/RST
/RST
RN5
10k
RN6
4.7K
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
JPN1
PORTE
1
2
3
4
5
6
7
8
JPN2
PORTA
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
PA0
PA1
PA2
PA3
PA7
RXD
TXD
MISO
P_INT*
PA4
PA5
PA6
P_RST*
P_CS*
LED_RED
LED_GRN
SW_BOT
SW_TOP
MODE
E_CS*
E_SO
E_SI
E_SCK
MOSI
SCK
RN7
10k
+5v
P_INT*
P_INT*
RXD
RXD
MISO
MISO
P_RST*
P_RST*
P_CS*
P_CS*
LED_RED
LED_RED
LED_GRN
LED_GRN
E_CS*
E_CS*
E_SI
E_SI
E_SCK
E_SCK
TXD
TXD
MOSI
MOSI
SCK
SCK
Schematic of Additionas to Development Board

Home Automation, Power Lines and the Internet Quenten Alick
Appliance
0.1R 7W
33K
47nF
33K
Power Measurement Circuit Design
47nF
3
2
- 39 -
On / Off
+5V
8
4
5A FUSE
U1A
1
LM358
10K
56K
100K
+5V
1K
PNP
RELAY-SPST
5
6
220K
U1B
560K
7
LM358
Power Active
To ADC
Power Neutral

Appendix B – Printed Circuit Board
Top Layer of the PCB
Middle Power Layers of the PCB

Home Automation, Power Lines and the Internet Quenten Alick
Bottom Layer of the PCB
- 41 -

Home Automation, Power Lines and the Internet Quenten Alick
Appendix C – Code Flowcharts
Flowchart for reading from the P300 Network Chip
- 42 -

Home Automation, Power Lines and the Internet Quenten Alick
Flowchart for Initialization of the P300 Network Chip
- 43 -

Home Automation, Power Lines and the Internet Quenten Alick
Appendix D – Assembler Code Listing
*--------------------------------------------------------------------
* tser7.asc
* P300 Initialisation and Serial (SPI) link
* Author: Tony Truong
*--------------------------------------------------------------------
TCTL1 EQU $1020
TCTL2 EQU $1021
TFLG1 EQU $1023
TFLG2 EQU $1025
PORTB EQU $1004
PORTC EQU $1003
PORTD EQU $1008
PORTA EQU $1000
PORTE EQU $100A
DDRC EQU $1007
DDRD EQU $1009
PACTL EQU $1026
TMSK2 EQU $1024
TOC2 EQU $1018
TIC3 EQU $1014
ADCTL EQU $1030
ADR1 EQU $1031
OPTION EQU $1039
BAUD EQU $102B
SCCR1 EQU $102C
SCCR2 EQU $102D
SCSR EQU $102E
SCDR EQU $102F
SPDR EQU $102A
SPCR EQU $1028
SPSR EQU $1029
CONTROL EQU $8000 *LCD control
DATA EQU $8001 *LCD data
BIT0 EQU $01
BIT1 EQU $02
BIT2 EQU $04
BIT3 EQU $08
BIT4 EQU $10
BIT5 EQU $20
BIT6 EQU $40
BIT7 EQU $80
MASK1 EQU $80
REG EQU $1000
TIE EQU $88
RECVEN EQU $24
TRANSEN EQU $88
TRUE EQU $01
ISRIDLE EQU $01
ISRXLEN EQU $02
ISRX EQU $03
ISRRLEN EQU $20
ISRRCV EQU $30
*****************************
* Variables
*****************************
ORG $0000
COUNT RMB 1
MODE RMB 1
*SCIFLAG RMB 1
*SPIFLAG RMB 1
POINTER RMB 2
POINTR2 RMB 2
POINTR3 RMB 2
DIVTMP RMB 2
*RCVCNT RMB 1
- 44 -
*TRNCNT RMB 1
LENGTH RMB 1
STORE FDB $0020
STORE2 FDB $0030
*----------------------------
* IRQ Interrupt vector
*----------------------------
ORG $00EE
JMP ISR
*----------------------------
* auto jump vector
*----------------------------
ORG $B600
JMP BEGIN
*****************************
ORG $C000 *Start of program
*****************************
*--------------------------------------------------------------------
* init stack and other setup stuff
*--------------------------------------------------------------------
BEGIN LDAA OPTION
ORAA #BIT5
STAA OPTION
* hardware reset for the P300
CLR PORTB
LDS #$00C3
* setup IO ports for output only
LDAA #$FF
STAA DDRC
* setup data direction for portD for master
LDAA #$38
STAA DDRD
* setup serial peripheral interface w/O interrupt
LDAA #$5C
STAA SPCR
* setup input capture 2
LDAA #BIT2
STAA TCTL2
LDAA #$01
STAA TMSK2
CLR COUNT
*--------------------------------------------------------------------
* LCD INITIALIZATION
*--------------------------------------------------------------------
LDY #CONTROL
CONFIG1 BRSET 0,Y,#BIT7,CONFIG1
LDAA #$30 * FUNCTION SET
STAACONTROL
CONFIG2 BRSET 0,Y,#BIT7,CONFIG2
LDAA #$0F * DISPLAY SETTING
STAACONTROL
CONFIG3 BRSET 0,Y,#BIT7,CONFIG3
LDAA #$07 * SET CURSOR MOVEMENT
STAACONTROL
CONFIG4 BRSET 0,Y,#BIT7,CONFIG4
LDAA #$01 * CLEAR DISPLAY
STAACONTROL
CONFIG5 BRSET 0,Y,#BIT7,CONFIG5
LDAA #$90
STAA CONTROL * DD RAM START LOCATION
LDAB OPTION

Home Automation, Power Lines and the Internet Quenten Alick
LDAA #$00
JSR DIVIDE
*--------------------------------------------------------------------
* Setup the buffer for the layer config commands and data
*--------------------------------------------------------------------
* setup the layer config info of the P300
CLR COUNT
LDX STORE
STX POINTER
* store the bytes
LDAA #$03 * command byte
STAA 0,X
INX
LDAA #$07 * length byte
STAA 0,X
INX
LDAA #$78 * data byte 0 ?
STAA 0,X
INX
* store the next 6 data bytes with 0
STDATA LDAA #6
CMPA COUNT * check if COUNT has
reached 6 yet
BEQ LAYER * goto LAYER if it has
INC COUNT * otherwise increment
COUNT
LDAA #0 * and store 0
STAA 0,X * to position indexed by
register X
INX * and increment the index
pointer
BRA STDATA
*--------------------------------------------------------------------
* Start of Main Program
*--------------------------------------------------------------------
* send the layer config info
LAYER CLR COUNT
CLR LENGTH
CLR MODE
LDAA #$FF
STAA PORTC * deassert CS*
STAA PORTB * deassert RST*
* wait for 52ms to allow P300 to come out of reset state
LDD #26000 * 52 ms
ADDD TOC2
STD TOC2
TIMER LDY #TFLG1
BRCLR 0,Y,#BIT6,TIMER
LDAA #BIT6
STAA TFLG1
LDAB #44 * debug
LDAA #0 * debug
JSR DIVIDE * debug
CLR PORTC * assert CS*
* -----------------------
* wait for push button
*------------------------
WAIT LDY #TFLG1
BRCLR 0,Y,#BIT1,WAIT
LDAA #BIT1
STAA TFLG1
*-----------------------
* send the LW command
*-----------------------
LDX STORE * Get the address of the
LW buffer
STX POINTER * Save it as an index pointer
- 45 -
LDAB 0,X * Get the command byte
LDAA #$00
JSR DIVIDE * debug
INX * Advance the index
pointer
STX POINTER
STAB SPDR * start the SPI transfer
* wait for the transfer to finish
WAIT2 LDAA SPSR
BPL WAIT2
LDAB #ISRXLEN * Set the mode to...
STAB MODE ...transmitting length
CLI * turn on interrupt
* wait for all the bytes to be sent
WAIT3 LDAA #ISRIDLE
CMPA MODE
BNE WAIT3
LDD #$0000
LDAB COUNT
JSR DIVIDE
*-----------------------
* wait for push button
*-----------------------
WAIT4 LDY #TFLG1
BRCLR 0,Y,#BIT1,WAIT4
LDAA #BIT1
STAA TFLG1
*-----------------------
* send the IR command
*-----------------------
CREAD CLR COUNT
CREAD2 LDX STORE2
STX POINTR2
LDAA #$04
STAA SPDR
CREAD3 LDAA SPSR
BPL CREAD3
LDAA #ISRRLEN
STAA MODE
CLI
CREADTS LDAA #ISRIDLE
CMPA MODE
BNE CREADTS
LDAA #$FF
STAA PORTC
***************************************************
* ISR
***************************************************
ISR PSHA
PSHB
PSHX
* check for which mode, idle, transfer, if neither then read
LDAA MODE
CMPA #ISRIDLE * is it idling now?
BEQ ISROFF
CMPA #ISRX * is it transmitting the
data?
BEQ ISRW

Home Automation, Power Lines and the Internet Quenten Alick
CMPA #ISRXLEN * is it transmitting the
length?
BEQ ISRWLEN
CMPA #ISRRCV * is it receiving the data?
BEQ ISRR
CMPA #ISRRLEN * is it receiving the
length?
BEQ ISRLEN
BRA ISRDONE
*-------------------------------------------------------------
* write command: transfer length byte
*-------------------------------------------------------------
ISRWLEN LDX POINTER * Retrieve
current index
LDAA 0,X * Get
length
STAA LENGTH * Store length
STAA SPDR * Start
the transfer of the length
WLWAIT LDAA SPSR * Wait for
the transfer...
BPL WLWAIT ...to finish
LDAA #ISRX * Change
the mode...
STAA MODE ...to transmitting data
INX
STX POINTER
BRA ISRDONE
*--------------------------------------------------------------
* write command: transfer data
*--------------------------------------------------------------
ISRW LDAA LENGTH * Test for
the interrupt...
CMPA COUNT ...after the last byte
BEQ ISROFF
LDX POINTER * Retrieve the current
index
LDAA 0,X * Get the
data
STAA SPDR * Start
the transfer of the data
INC COUNT *
Increment number of data sent
INX *
Advance the index pointer
STX POINTER
WWAIT LDAA SPSR * Wait for the transfer...
BPL WWAIT ...to finish
BRA ISRDONE
*--------------------------------------------------------------
* read command: get the length byte
*--------------------------------------------------------------
ISRLEN LDAA #0 * Start the transfer with
a...
STAA SPDR ...dummy input of 0
LWAIT LDAA SPSR * Wait for the transfer...
BPL LWAIT ...to finish
LDAA SPDR * Get the
length value...
STAA LENGTH ...and store it
LDX POINTR2 * Get the store index
pointer...
STAA 0,X ...and
store it
INX *
Advance the pointer
STX POINTR2
- 46 -
LDAA #ISRRCV * Change the mode...
STAA MODE ...to receiving data
BRA ISRDONE
* If you have read this please underline.
*---------------------------------------------------------------
* read command: get data and wait for interrupt after last
byte
*---------------------------------------------------------------
ISRR LDAA LENGTH * Test for the interrupt...
CMPA COUNT ...after the last byte
BEQ ISROFF
LDAA #0 * Start
the transfer with a...
STAA SPDR ...dummy input of 0
RWAIT LDAA SPSR * Wait for the transfer...
BPL RWAIT ...to finish
LDX POINTR2 * Get the store index
pointer
LDAA SPDR * Get the
data
STAA 0,X * Store
the data
INX *
Advance the store index pointer
STX POINTR2
INC COUNT *
Increment the data count
BRA ISRDONE
*----------------------------------------------------------------
ISROFF LDAA #ISRIDLE
STAA MODE
SEI
ISRDONE PULX
PULB
PULA
RTRN RTI * return
from interrupt
*****************************************************************
**
*--------------------------------------------------------------------
* WRITE SUBROUTINE
*--------------------------------------------------------------------
WRITES LDAA MODE
LDX POINTER
LDAB 0,X * get the
next byte
STAB SPDR * start the
SPI transfer
INC COUNT
* wait for the transfer to finish
WRWAIT LDAA SPSR
BPL WRWAIT
INX
STX POINTER
RTS
*--------------------------------------------------------------------
* READ SUBROUTINE
*--------------------------------------------------------------------
* load dummy byte to start xfers
READS LDAA #$00
STAA SPDR
* wait for spif (when xfer complete)
ISRWAIT LDAA SPSR

Home Automation, Power Lines and the Internet Quenten Alick
BPL ISRWAIT
* read the recieved data and store in buffer
RSTORE LDAA SPDR
RSTORE2 LDX POINTR2
STAA 0,X
INX
STX POINTR2
INC COUNT
RTS
*--------------------------------------------------------------------
* DIVIDE SUBROUTINE
*--------------------------------------------------------------------
DIVIDE PSHX
LDX #100
IDIV * DIVIDE D REG WITH
100 TO GET THE HUNDREDS
STD DIVTMP * STORE THE
REMAINDER
XGDX * PUT THE RESULT IN D
TBA * SINCE D IS A&B SWAP
SO WE CAN JUMP TO LCD SUB
JSR LCD
LDX #10
LDD DIVTMP * GET OUR REMAINDER
IDIV * DIVIDE BY 10 TO GET
OUR TENS
STD DIVTMP * STORE OUR
REMAINDING ONES
XGDX
TBA
JSR LCD
LDX #1
LDD DIVTMP * GET OUR REMAINDER
IDIV * DON'T ASK WHY BUT
IT DOESN'T WORK OTHER WAYS
XGDX
TBA
JSR LCD
PULX
RTS
*--------------------------------------------------------------------
* LCD SUBROUTINE
*--------------------------------------------------------------------
LCD PSHY
LDY #CONTROL
CMPA #0
BEQ ZERO
CMPA #1
BEQ ONE
CMPA #2
BEQ TWO
CMPA #3
BEQ THREE
CMPA #4
BEQ FOUR
CMPA #5
BEQ FIVE
CMPA #6
BEQ SIX
CMPA #7
BEQ SEVEN
CMPA #8
BEQ EIGHT
- 47 -
CMPA #9
BEQ NINE
BRA DEFAULT
ZERO BRSET 0,Y,#BIT7,ZERO
LDAA #$30
STAA DATA
BRA LCDDONE
ONE BRSET 0,Y,#BIT7,ONE
LDAA #$31
STAADATA
BRA LCDDONE
TWO BRSET 0,Y,#BIT7,TWO
LDAA #$32
STAADATA
BRA LCDDONE
THREE BRSET 0,Y,#BIT7,THREE
LDAA #$33
STAADATA
BRA LCDDONE
FOUR BRSET 0,Y,#BIT7,FOUR
LDAA #$34
STAADATA
BRA LCDDONE
FIVE BRSET 0,Y,#BIT7,FIVE
LDAA #$35
STAADATA
BRA LCDDONE
SIX BRSET 0,Y,#BIT7,SIX
LDAA #$36
STAADATA
BRA LCDDONE
SEVEN BRSET 0,Y,#BIT7,SEVEN
LDAA #$37
STAADATA
BRA LCDDONE
EIGHT BRSET 0,Y,#BIT7,EIGHT
LDAA #$38
STAADATA
BRA LCDDONE
NINE BRSET 0,Y,#BIT7,NINE
LDAA #$39
STAADATA
DEFAULT BRA LCDDONE
LCDDONE PULY
RTS
END
*--------------------------------------------------------------------
* tser.asm
* receive data from PC and send to PORTB
* Serial (SCI) link
* $Author: Quentin Alick & Tony Truong
*--------------------------------------------------------------------
TCTL1 EQU $1020
TCTL2 EQU $1021
TFLG1 EQU $1023
TFLG2 EQU $1025
PORTB EQU $1004
PORTC EQU $1003
PORTD EQU $1008
PORTA EQU $1000
PORTE EQU $100A
DDRC EQU $1007
DDRD EQU $1009
PACTL EQU $1026
TMSK2 EQU $1024
TOC2 EQU $1018

Home Automation, Power Lines and the Internet Quenten Alick
TIC3 EQU $1014
ADCTL EQU $1030
ADR1 EQU $1031
OPTION EQU $1039
BAUD EQU $102B
SCCR1 EQU $102C
SCCR2 EQU $102D
SCSR EQU $102E
SCDR EQU $102F
CONTROL EQU $8000 *LCD control
DATA EQU $8001 *LCD data
BIT0 EQU $01
BIT1 EQU $02
BIT2 EQU $04
BIT3 EQU $08
BIT4 EQU $10
BIT5 EQU $20
BIT6 EQU $40
BIT7 EQU $80
MASK1 EQU $80
REG EQU $1000
TIE EQU $88
RECVEN EQU $24
TRANSEN EQU $88
*****************************
* Variables
*****************************
ORG $0000
COUNT RMB 1
SCIFLAG RMB 1
POINTER RMB 2
POINTR2 RMB 2
POINTR3 RMB 2
DIVTMP RMB 2
RCVCNT RMB 1
TRNCNT RMB 1
LENGTH RMB 1
STORE FDB $0020
*----------------------------
* SCI interrupt vector
*----------------------------
ORG $00C4
JMP SCIISR
*----------------------------
* SPI Interrupt vector
*----------------------------
*****************************
ORG $C000 *Start of program
*****************************
*--------------------------------------------------------------------
* init stack and other setup stuff
*--------------------------------------------------------------------
LDS #$00C3
* setup IO ports for output only
LDAA #$FF
STAA DDRC
STAA DDRD
* init SCI interface, 9600, 8N1, recv
LDAA #$30
STAA BAUD
LDAA #$00
STAA SCCR1 * 8N1
LDAA #RECVEN * enable recv w/ ints
STAA SCCR2 * recv
* STAA RDATA * set init state
- 48 -
* init the storage index and set input capture 2 for low -
high
LDX STORE
STX POINTER
STX POINTR2
LDAA #BIT2
STAA TCTL2
* init variables
CLR RCVCNT
CLR TRNCNT
CLR LENGTH
CLI
START LDX STORE
STX POINTR3
CLR COUNT
* poll for a pushbutton on IC2 (PA1)
LOOP LDY #TFLG1
BRCLR 0,Y,#BIT1,LOOP
LDAA #BIT1 * clear flag
STAA TFLG1
LDD #$0000
LDAB LENGTH
JSR DIVIDE
INC COUNT
LDX POINTR3
LDAA 0,X * output the data
STAA PORTB
INX
STX POINTR3
* check if we have output all the data
* reset variables if so otherwise move onto next data
LDAA LENGTH
INCA
INCA
CMPA COUNT
BEQ START
BRA LOOP
***************************************************
* SCI ISR
***************************************************
SCIISR LDAB SCSR
STAB SCIFLAG *store flags for later checks
* check for valid recv interrupt
BRSET SCIFLAG,#BIT5,RECV
* check for valid trans interrupt
BRSET SCIFLAG,#BIT7,TRANS
* else invalid interrupt
BRA RTRN
*---------------------------------------
* valid receive interrupt
*---------------------------------------
RECV LDAB SCDR * read the data reg
LDY POINTER * load the index pointer
STAB 0,Y * store at index
INC RCVCNT
CHECK1 LDAB #$02 * check to see if
CMPB RCVCNT * its the second packet
BNE CHECK2 * if not then goto CHECK2...
LDY POINTER * if it is the second packet
LDAB 0,Y * we have the length byte

Home Automation, Power Lines and the Internet Quenten Alick
STAB LENGTH * so store it in a variable
CHECK2 LDAB LENGTH * check to see if the number
of
INCB * packet received is equal to
INCB * == length of data + first command
byte + length byte
CMPB RCVCNT * i.e is length + 2 = rcvcnt ?
BNE DONE * if not then goto DONE
* if the length of data + 2 is equal to the num of
packet receive
* then do something here, like echo back.
* turn on the transmit interrupt and disable the
receive interrupt
* note that TDRE is already set so once this routine
is returned
* it will call an interrupt
LDAA #TRANSEN
STAA SCCR2
DONE LDY POINTER * increase
INY * the index pointer
STY POINTER * by one
JMP RTRN
*---------------------------------------
* valid transmit interrupt
*---------------------------------------
TRANS LDAB LENGTH * check to see if the number
of
- 49 -
INCB * packet transmitted is equal to
INCB * == length of data + first command
byte + length byte
CMPB TRNCNT * ie. is length + 2 = trncnt ?
BNE MORE * if not then goto MORE
* the entire message has been sent so disable the
transmit interrupt
* and enable the receive interrupt again.
* for now just turn off the entire thing
* LDY STORE
* STY POINTR2
* CLR TRNCNT
CLR SCCR2
MORE LDY POINTR2 * get the message current
location
LDAB 0,Y * get the byte in the message
STAB SCDR * store it in the data reg, this also
clears TDRE
INC TRNCNT * increase the transmitted byte
count
INY
STY POINTR2
RTRN RTI * return from int

Home Automation, Power Lines and the Internet Quenten Alick
Appendix E – C Code Listing
* Trying to add recieve (hc11 transmit) to the programme
- needed for overrun
*
* Quenten Alick
* 3/8/99
*
* Modified by Tony Truong
* 17/8/99
*/
#include
#include
#include
#include
#include
#include
#include
#include
/* baudrate settings are defined in ,
which is
included by */
#define BAUDRATE B9600
/* change this definition for the correct port */
#define SERIALDEVICE "/dev/ttyS1"
#define _POSIX_SOURCE 1 /* POSIX compliant source
*/
#define FALSE 0
#define TRUE 1
#define DATA 0x0d
volatile int STOP=FALSE;
void main(void)
{
int fd,c, res;
double i;
int j;
int cnt;
int baud_ok;
struct termios oldtio,newtio;
unsigned char buffer;
unsigned char recvbuf;
/*
Open serial device for reading and writing and not as
controlling tty
because we don't want to get killed if linenoise sends
CTRL-C.
*/
fd = open(SERIALDEVICE, O_RDWR | O_NOCTTY |
O_NONBLOCK);
if (fd

Home Automation, Power Lines and the Internet Quenten Alick
if (errno == 11) {
fprintf (stdout, "this error ok, data not there yet.
implementation for retries / timeout not done!\n");
exit(1);
}
else {
fprintf (stdout, "read error!\tbytes read: %d\terrno:
%d\n", cnt, errno);
}
}
printf("receive: -%p-\n", recvbuf);
/*
* delay to prevent overruns, will have to be
implemented with ack - checking OR flag in hc11
*/
for(i = 0; i < 500000; i++)
;
/*sleep(1);*/
}
}
/*
* Original Author: Stan JK
*
* Modified by: Tony Truong
*
* File: mod_main.c
*/
#define _mod_main_owner
#include "standard.h"
void main( void )
{
DisableInterrupts();
ResetStackPtr();
/*
* initialize all ports, set all directions as inputs and
* clear all control registers
*/
PORTB = 0xff;
PORTC = 0;
PORTD = 0x20; /* keep SS* off */
DDRA = 0;
DDRB = 0;
DDRC = 0;
DDRD = 0;
SPCR = 0;
SCCR1 = 0;
SCCR2 = 0;
RST = LOW;
COPCR = 0; /* Disable watchdog */
DDRC = PORTCdirection;
DDRD = PORTDdirection;
/*
* set master mode
* set SCK polarity at logic 1
* set SCK phase to edge after 1 st to latch
* set SPI clock rate
* and enable SPI
*/
SPCR = MSTR | CPOL | CPHA | SPR | SPE;
NIC_CS = HIGH;
EEROM_CS = HIGH;
RST = HIGH;
- 51 -
/*
* wait for NIC to complete its internal reset
* wait for approx 51.2 msec.
*/
*i = GetLowResTimeByte() + 100;
while(*i != GetLowResTimeByte()) ;
/*
* Initialize utilities/layers and execute application:
*/
InitializeTimer();
EnableInterrupts();
InitializeSerial();
/*
* wait for initailize to compete
*/
if(InitializeEval()) {
While(1)
UpdateEval();
}
}
/*
* Original Author: Stan JK
*
* Modified and adapted for the MCHC11A1 by: Tony
Truong
*
* File: evaluate.c
*/
#include "standard.h"
/*
* transmitter device to RS232 host command functionIDs
*/
#define ABORT_CMD ('A')
#define DELAY_CMD ('D')
#define NIC_ID_CMD ('N')
#define PROGRESS_CMD ('P')
#define QUERY_CMD ('Q')
#define RUNNING_CMD ('R')
#define STATS_CMD ('S')
#define TRANS_START_CMD ('T')
/*
* transmitter device to remote device info field headers
*/
#define SETUP_PKT 0x01
#define LOOPBACK_PKT 0x02
#define COUNT_RESP_PKT 0x03
#define RESET_COUNT 0x04
#define GET_COUNT_PKT 0x05
#define TRANS_PKT 0x0f
/*
* timer value based on 131msec/tick
*/
#define TWO_SECS 14
void RecdRunningCmd(void);
void RecdSetupPkt(void);
void XmitOriginal(void);
void StatsToHost(boolean recdPkts);
boolean ProcessTransmitEnd(boolean forced);
void ProcessValidPacket(void);
booleans EV;
booleans EV2;

Home Automation, Power Lines and the Internet Quenten Alick
#define transmitter (EV.b0) /* set when
transmitter device */
#define transmitCompleted (EV.b1)
#define GetCountRecd (EV.b2)
#define TransPktRecd (EV.b3)
#define transmitting (EV.b4)
#define responseTimerRunning (EV.b5)
#define waitingForLoopback (EV.b6)
#define testRunning (EV.b7)
#define LoopbackPktReady (EV2.b0)
uint8 type;
/*
* transmitter device counters
*/
unsigned short int txMax;
unsigned short int txSuccess;
unsigned short int txRcvValid;
uint8 txLength;
uint8 txService;
unsigned short int txCount;
/*
* timer used while waiting for looped back or response
packet from remote device
*/
uint8 response_timer;
/*
* remote device counters
*/
unsigned short int rxCount;
unsigned short int rxValidCount;
uint8 InitializeEval( void )
{
#define MAX_RESTARTS 0x0f
boolean validPacket;
boolean Initialized = FALSE;
/*
* initialize flags and progress LED
*/
LED_1 = OFF;
responseTimerRunning = FALSE;
waitingForLoopback = FALSE;
transmitCompleted = FALSE;
testRunning = FALSE;
LoopbackPktReady = FALSE;
GetCountRecd = FALSE;
TransPktRecd = FALSE;
config.modeByte = DLL | (MAX_RESTARTS

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/*
* continually update logical link background process
*/
UpdateLL();
/*
* REMOTE DEVICE:
*
* after the "get count" packet has been received, and
when the transmit
* buffer becomes available, load the "received valid
counter" value
* and transmit to the transmitter device
*/
if(GetCountRecd && TxBfrAvailable) {
GetCountRecd = FALSE;
txLPDU.LPDUheader = rxLPDU.LPDUheader;
txLPDU.DA.LSB = 0x01;
txLPDU.DA.MSB = 0x00;
txLPDU.DHC.LSB = config.systemAddr.LSB;
txLPDU.DHC.MSB = config.systemAddr.MSB;
txLPDU.SA.LSB = config.unitAddr.LSB;
txLPDU.SA.MSB = config.unitAddr.MSB;
txLPDU.SHC.LSB = config.systemAddr.LSB;
txLPDU.SHC.MSB = config.systemAddr.MSB;
txLPDU.LSDU[0] = COUNT_RESP_PKT;
txLPDU.LSDU[1] = HIGH_BYTE_OF(rxValidCount);
txLPDU.LSDU[2] = LOW_BYTE_OF(rxValidCount);
txLPDU.LPDUlength = CEBUS_HEADER_LEN + 3;
transmitCompleted = FALSE;
TransmitPacket(USE_WTI | USE_DELAY); /* use
WTI w/ delay */
/*
* background processing is complete--free
receive packet buffer resource
*/
RxBfrAvailable = TRUE;
}
/*
* REMOTE DEVICE:
*
* after the "transmit" packet has been received, and
when the transmit buffer becomes available, validate the
received "transmit" packet and, if valid, create the "loop
back" packet and queue the transmission via
LoopbackPktReady (see ProcessValidPacket())
*
* toggle progress LED after every 10 packets with valid
counts
* NOTE: A "valid" packet contains valid count AND
valid info in rest
* of body (see ProcessValidPacket())
*/
if (TransPktRecd && TxBfrAvailable) {
TransPktRecd = FALSE;
/*
* get received packet's count
*/
tempCtr = (((unsigned short int)rxLPDU.LSDU[1]) rxCount) {
rxCount = tempCtr + 1;
ProcessValidPacket();
}
if ((rxCount % 10) == 0)
LED_1 = !LED_1;
/*
* background processing is complete--free
receive packet buffer resource
*/
RxBfrAvailable = TRUE;
}
/*
* TRANSMITTER & REMOTE DEVICES:
* get current transmit status and process
*/
status = ConfirmTransmitPacket();
if (status==SUCCESS || status==FAILURE)
if(transmitting && (status==SUCCESS) )
txSuccess++;
transmitCompleted = TRUE;
}
/*
* TRANSMITTER DEVICE:
* when currently transmitting and after completing a
transmit and when
* no longer waiting for the remote device to loop back
the packet,
* process the next transmit packet unless the transmit
test is ended
*/
if (transmitting && !waitingForLoopback &&
transmitCompleted)
if(!ProcessTransmitEnd(FALSE)) /* if not end,
transmit next packet */
XmitOriginal();
/*
* REMOTE DEVICE:
* when loopback packet is loaded and transmit
completed, send loopback
* packet to transmitter device
*/
if(LoopbackPktReady && transmitCompleted) {
LoopbackPktReady = FALSE;
transmitCompleted = FALSE;
TransmitPacket(USE_WTI | USE_DELAY);
}
/*
* TRANSMITTER DEVICE:
* if "loopback" or response packet has not been
received from remote device
* in two seconds, continue with next transmit or send
transmitter device ONLY
* statistics to host
*/
if(responseTimerRunning) {
if(response_timer == GetVeryLowResTimeByte()
) else {
responseTimerRunning = FALSE;
if(waitingForLoopback) {
if(!ProcessTransmitEnd(FALSE)) /* if not end, transmit
next packet */
XmitOriginal();
} else {

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}
}
}
StatsToHost(FALSE);
/*
* TRANSMITTER DEVICE:
* process commands from host
*/
if (rbufferValid) { /* command from RS232 */
if(transmitter) {
if(rbuffer.functionID == RUNNING_CMD) {
/*
* process "run" command
*/
RecdRunningCmd();
} else if (rbuffer.functionID == ABORT_CMD) {
/*
* clear running flags
*/
testRunning = FALSE;
transmitting = FALSE;
responseTimerRunning = FALSE;
} else if(rbuffer.functionID ==
DELAY_CMD) {
/*
* set interpacket delay flag (remote device gets
updated at
* start of test via "reset count" packet)
*/
if(rbuffer.buf[0] == 0)
UseDelay = FALSE;
else
UseDelay = TRUE;
} else if(rbuffer.functionID == QUERY_CMD) {
host
/*
* set running flags, retrieve statistics and send to
*/
transmitter = TRUE;
testRunning = TRUE;
ProcessTransmitEnd(TRUE); /* force end */
} else if(rbuffer.functionID ==
TRANS_START_CMD) {
/*
* accept "start" command only if not already in test
*
* retrieve parameters from host
* send "reset counter" and interpacket delay flag to
remote device
* set waitingForLoopback to kick off the transmission of
packets
*/
if (!testRunning) {
LED_1 = OFF;
testRunning = TRUE;
txMax = (((unsigned short int)rbuffer.buf[1])

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* TRANSMITTER DEVICE and test in
process:
*
* validate "loop back" packet and set
counter accordingly
*/
if
LOOPBACK_PKT) {
(rxLPDU.LSDU[0] ==
responseTimerRunning =
FALSE; /* kill wait timer */
/*
* compare received to transmitted
*/
validCompare = TRUE;
if (( (rxLPDU.LPDUheader &
~SEQUENCE_NO) ==
(txLPDU.LPDUheader
~SEQUENCE_NO) ) &&
(rxLPDU.SA.LSB == 0x02) &&
(rxLPDU.SA.MSB == 0x00) &&
&
(rxLPDU.SHC.LSB
config.systemAddr.LSB) &&
==
(rxLPDU.SHC.MSB
config.systemAddr.MSB) &&
==
(rxLPDU.LPDUlength
txLPDU.LPDUlength) ) {
==
for(i=1;i

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* TRANSMITTING DEVICE:
*
* retrieve house code and initialize NIC
*/
config.systemAddr.MSB = rbuffer.buf[1];
config.systemAddr.LSB = rbuffer.buf[0];
config.unitAddr.LSB = 0x01;
config.unitAddr.MSB = 0x00;
transmitter = TRUE; /* set transmitter device
status */
testRunning = FALSE;
DisableInterrupts();
rbuffer.state = REC_IDLE; /* reset serial state to
idle */
EnableInterrupts();
InitializeLL();
/*
* transmit "setup" packet to remote device if transmit
buffer available
*/
if(TxBfrAvailable) {
txLPDU.LPDUheader = UNACK |
STD_PRIORITY | BASIC_SERVICE;
txLPDU.DA.LSB = 0x00;
txLPDU.DA.MSB = 0x00;
txLPDU.DHC.LSB = 0x00;
txLPDU.DHC.MSB = 0x00;
txLPDU.SA.LSB = config.unitAddr.LSB;
txLPDU.SA.MSB = config.unitAddr.MSB;
txLPDU.SHC.LSB = config.systemAddr.LSB;
txLPDU.SHC.MSB = config.systemAddr.MSB;
txLPDU.LSDU[0] = SETUP_PKT;
*(uint16 *)&txLPDU.LSDU[1] = config.systemAddr;
txLPDU.LPDUlength = CEBUS_HEADER_LEN + 3;
transmitCompleted = FALSE;
TransmitPacket(0); /* use PT command w/o delay */
/*
* respond to host with NIC type
*/
if(!tbufferInUse) {
tbuffer.functionID = NIC_ID_CMD;
tbuffer.buf = &type;
ResponseToHost(sizeof(uint8));
}
transmitting = FALSE; /* wait for "start"
command */
}
}
void RecdSetupPkt( void )
{
/*
* REMOTE DEVICE:
*
* retrieve house code and initialize NIC
*/
config.systemAddr.MSB = rxLPDU.LSDU[2];
config.systemAddr.LSB = rxLPDU.LSDU[1];
config.unitAddr.LSB = 0x02;
config.unitAddr.MSB = 0x00;
transmitter = FALSE; /* set remote device
status*/
InitializeLL();
/*
* reset counters
*/
rxCount = 0;
rxValidCount = 0;
}
- 56 -
void XmitOriginal( void )
{
uint8 i; /* local counter */
static uint8 temp[2]; /* temporary storage */
/*
* TRANSMITTING DEVICE:
*
* load contents of transmit buffer (if available) with
running transmit
* count and fill rest of info field (up to host specified
length)
* with predictable data (for comparison purposes at
remote device)
*/
if (TxBfrAvailable) {
txLPDU.LPDUheader = txService |
STD_PRIORITY | BASIC_SERVICE;
txLPDU.DA.LSB = 0x02;
txLPDU.DA.MSB = 0x00;
txLPDU.DHC.LSB = config.systemAddr.LSB;
txLPDU.DHC.MSB = config.systemAddr.MSB;
txLPDU.SA.LSB = config.unitAddr.LSB;
txLPDU.SA.MSB = config.unitAddr.MSB;
txLPDU.SHC.LSB = config.systemAddr.LSB;
txLPDU.SHC.MSB = config.systemAddr.MSB;
txLPDU.LSDU[0] = TRANS_PKT;
txLPDU.LSDU[1] = HIGH_BYTE_OF(txCount);
txLPDU.LSDU[2] = LOW_BYTE_OF(txCount);
for(i=0;i

Home Automation, Power Lines and the Internet Quenten Alick
*
* send statistics to host
*/
if (!tbufferInUse) {
tbuffer.functionID = STATS_CMD;
temp[0] = LOW_BYTE_OF(txSuccess);
temp[1] = HIGH_BYTE_OF(txSuccess);
if (recdPkts) {
temp[2] = rxLPDU.LSDU[2];
temp[3] = rxLPDU.LSDU[1];
}
else {
temp[2] = 0;
temp[3] = 0;
}
temp[4] = LOW_BYTE_OF(txRcvValid);
temp[5] = HIGH_BYTE_OF(txRcvValid);
tbuffer.buf = temp;
ResponseToHost(6);
testRunning = FALSE;
}
}
boolean ProcessTransmitEnd( boolean forced )
{
/*
* TRANSMITTING DEVICE:
*
* when forced (as result of "query" host command) or
when the running
* transmit counter equals the number of host
determined packets, send
* "get count" packet to remote device
*
* return TRUE only if "get count" packet sent to remote
device
*/
if (forced || (txCount == txMax)) {
transmitting = FALSE;
/*
* transmit "get count" packet
*/
if (TxBfrAvailable) {
txLPDU.LPDUheader = txService |
STD_PRIORITY | BASIC_SERVICE;
txLPDU.DA.LSB = 0x02;
txLPDU.DA.MSB = 0x00;
txLPDU.DHC.LSB = config.systemAddr.LSB;
txLPDU.DHC.MSB = config.systemAddr.MSB;
txLPDU.SA.LSB = config.unitAddr.LSB;
txLPDU.SA.MSB = config.unitAddr.MSB;
txLPDU.SHC.LSB = config.systemAddr.LSB;
txLPDU.SHC.MSB = config.systemAddr.MSB;
txLPDU.LSDU[0] = GET_COUNT_PKT;
txLPDU.LPDUlength = CEBUS_HEADER_LEN +
1;
transmitCompleted = FALSE;
TransmitPacket(USE_WTI | USE_DELAY); /*
use WTI command w/ delay */
response_timer = GetVeryLowResTimeByte() +
TWO_SECS;
responseTimerRunning = TRUE;
waitingForLoopback = FALSE;
return TRUE;
} else {
return FALSE;
}
} else {
return FALSE;
}
}
- 57 -
void ProcessValidPacket( void )
{
boolean validCompare; /* comparison flag */
uint8 i; /* local counter */
validCompare = TRUE;
for(i=3;i

Home Automation, Power Lines and the Internet Quenten Alick
#define WTIX 0x0f /* NPDU_Field Write with Index */
#define WRS46 0x46 /* DLL_Access_Control Write */
#define RRS4 0x84 /* DLL_Rc_Link_Status Read */
/*
* Access control flags
*/
#define ENABLE_AUTO_RETRY 0x80 /* bit in NIC
DLL_Access_Control structure */
#define ENABLE_IMMEDIATE_RETRY 0x40
#define ADRUNACK_TRIES_4 0x02
#define DELAY_100MS 0x10
#define DELAY_200MS 0x20
#define DELAY_300MS 0x30
/*
* ServiceISR transmit/receive state machine states
*/
#define ISR_IDLE 0
#define ISR_XMIT_LEN 1
#define ISR_XMIT_BUF 2
#define ISR_RCV_LEN 3
#define ISR_RCV_BUF 4
#define ISR_ATTN 5
#define packetReceived (LL.b2)
#define rawPacketReceived (LL.b3)
#define receivePacketPending (LL.b4)
#define receiveHeaderPending (LL.b5)
void ReadCommand (uint8 command, @near uint8*
rawData, uint8* length);
void WriteCommand(uint8 command, @near uint8*
rawData, uint8 length);
uint8 basicTransmitStatus;
uint8 ISRstate;
TRANS_BFR transBfr;
boolean delayTimerRunning;
uint8 delayTimer;
boolean UseWTI;
uint8 NICtype;
uint8 GetNICtype ( void )
{
/*
* ID values in "status read" info from NIC
*/
#define P200_ID 0x03
#define P300_ID 0x04
#define ID_MASK 0x0f
uint8 statusStore[6]; /* for "status read" info */
uint8 len; /* length of expected data */
/*
** execute "status read" command and set NICtype
accordingly
*/
ReadCommand(SR,statusStore,&len);
NICtype = UNKNOWN_NIC;
statusStore[5] &= ID_MASK;
if(statusStore[5] & P300_ID)
NICtype = P300;
return NICtype;
}
uint8 InitializeLL ( void )
{
uint8 save[2]; /* local store */
/*
* initialize flags
*/
- 58 -
UseDelay = FALSE;
delayTimerRunning = FALSE;
UseWTI = FALSE;
/*
* write current "config" to NIC
*/
WriteCommand(LW,&config.modeByte,sizeof(CONFIG));
/*
* ignore extended service CEBus packets
*/
save[0] = 0;
save[1] = IGNORE_EXTENDED;
WriteCommand(CW,save,2);
save[0] = ENABLE_AUTO_RETRY |
ENABLE_IMMEDIATE_RETRY | ADRUNACK_TRIES_4;
WriteCommand(WRS46,save,1);
/*
* Initialize logical link semaphores/flags
*/
basicTransmitStatus = IDLE;
TxBfrAvailable = TRUE;
RxBfrAvailable = TRUE;
receivePacketPending = FALSE;
receiveHeaderPending = FALSE;
packetReceived = FALSE;
rawPacketReceived = FALSE;
return TRUE;
}
boolean ReceivePacket ( void )
{
if(packetReceived) {
packetReceived = FALSE;
return TRUE;
} else {
return FALSE;
}
}
boolean ReceiveRawPacket ( void )
{
if(rawPacketReceived) {
rawPacketReceived = FALSE;
return TRUE;
} else {
return FALSE;
}
}
interrupt void ServiceISR( void )
{
/*
switch(ISRstate) {
case ISR_XMIT_LEN:
SPDR = transBfr.len;
while(!spif) ; /* wait for transfer complete */
ISRstate = ISR_XMIT_BUF; /* change state */
break;
case ISR_XMIT_BUF:
if(transBfr.index == transBfr.len) {
ISRstate = ISR_IDLE; /* done */
} else {
SPDR = transBfr.buf[transBfr.index];
transBfr.index++;
while(!spif) ; /* wait for transfer complete */

Home Automation, Power Lines and the Internet Quenten Alick
}
break;
/*
* Read command: get length byte
*/
case ISR_RCV_LEN:
SPDR = 0;
while(!spif) ; /* wait for transfer complete */
transBfr.len = SPDR;
ISRstate = ISR_RCV_BUF; /* change state */
break;
case ISR_RCV_BUF:
if(transBfr.index == transBfr.len) {
ISRstate = ISR_IDLE; /* done */
} else {
SPDR = 0;
while(!spif) ;
if (transBfr.len

Home Automation, Power Lines and the Internet Quenten Alick
}
}
if(UseWTI) {
TransmitPacket(USE_WTI);
} else {
TransmitPacket(0);
}
}
void ReadCommand( uint8 command,
near uint8* rawData, /* O: page 1 data from NIC */
uint8* length ) /* O: length of data from NIC */
{
StartErrorTimer();
while((ISRstate!=ISR_IDLE) &&
(ISRstate!=ISR_ATTN)) {
TestErrorTimer(); /* test error timer and restart if
expired */
}
NIC_CS = LOW;
ISRstate = ISR_RCV_LEN;
transBfr.buf = rawData;
transBfr.index = 0; /* initialize index */
WriteToSPI(command);
StartErrorTimer();
while(ISRstate != ISR_IDLE) {
TestErrorTimer();
}
*length = transBfr.len;
NIC_CS = HIGH;
}
void riteCommand( uint8 command,
near uint8* rawData, /* I: page 1 data to NIC */
uint8 length ) /* I: length of data to NIC */
{
StartErrorTimer();
while((ISRstate!=ISR_IDLE) &&
(ISRstate!=ISR_ATTN)) {
TestErrorTimer();
}
NIC_CS = LOW;
ISRstate = ISR_XMIT_LEN;
transBfr.buf = rawData;
transBfr.len = length;
transBfr.index = 0;
WriteToSPI(command);
StartErrorTimer();
while(ISRstate != ISR_IDLE) {
- 60 -
TestErrorTimer(); /* test error timer and restart
if expired */
}
NIC_CS = HIGH;
}
/*
* Original Author: Stan JK
*
* Modified by: Tony Truong
*
* File: stamdard.h
*/
typedef unsigned char uint8;
typedef struct
{
uint8 LSB;
uint8 MSB;
} uint16;
typedef struct /* allows 8 boolean flags to coexist in
single uint8 */
{
uint8 b0 : 1;
uint8 b1 : 1;
uint8 b2 : 1;
uint8 b3 : 1;
uint8 b4 : 1;
uint8 b5 : 1;
uint8 b6 : 1;
uint8 b7 : 1;
} booleans;
typedef uint8 boolean;
#define FALSE 0
#define TRUE 1
#define INVALID 0
#define VALID 1
#define OFF 0
#define ON 1
#define LOW 0
#define HIGH 1
#define NULL 0
#define DisableInterrupts() _asm("\tsei\n")
#define EnableInterrupts() _asm("\tcli\n")
#define ResetStackPtr() _asm("\trsp\n")

Home Automation, Power Lines and the Internet Quenten Alick
References & Bibliography
[1] Buffkin E., CEBus, LonWorks heading for ‘homeLAN’, Electronic Engineering
Times, May 8, 1995, n847 pp.58-61.
[2] Datasheet for the Domosys CEWay PL-One is available from Domosys
Corporation Internet page: http://www.domosys.com
[3] Evans G, Digital Consumer Electronics Handbook, McGraw-Hill, N.Y., 1997,
pp29.1-29.19
[4] Hambley A.R, Electronics: A Top-Down Approach to Computer-Aided Circuit
Design, Prentice Hall, Englewood Cliffs New Jersey, 1994, pp525-527
[5] Holst W, Intelligent Homes (and X-10)
http://web.cs.ualberta.ca/~wade/HyperHome/top.html
[6] Information regarding the Apache Web Server is available from the Apache
Internet page: http://www.apache.org/
[7] Information regarding the IT5000 is available from ITRAN Communication
Internet page: http://www.itrancomm.com
[8] Information regarding embedded Linux is available from the Internet page:
http://www.thinlinux.org/
[9] Information regarding Linux serial communications is available from the
Internet pages:
http://sunsite.unc.edu/LDP/HOWTO/Serial-Programming-HOWTO.html
http://sunsite.unc.edu/LDP/HOWTO/Serial-HOWTO.html
- 61 -

Home Automation, Power Lines and the Internet Quenten Alick
[10] Information regarding the LONWorks standard is available from Echlons
Internet page:
http://www.echolon.com/
[11] Information regarding the Power Line Modem is available from VTT
Electronics Internet page: http://vtt.oulu.fi/
[12] Information regarding the RTU is available from Unique Collectric Internet
page: http://www.unique.co.il/ColPrdct/1-WayMU/W-1-WayMU.html
[13] Intellon Corporation, CEBus Power Line Encoding and Signaling, Intellon
White Paper #0027 Version 0.1, March 1997.
[14] Intellon Corporation, SSC P111 PL Media Interface IC, Technical Data Sheet
Revision 7, August 1998.
[15] Intellon Corporation, SSC P300 PL Network Interface Controller, Technical
Data Sheet Version 1.1, January 1998.
[16] Intellon Corporation, SSC P485 PL Transceiver IC, Technical Data Sheet
Version 1.1, July 1998.
[17] Miller G H, Microcomputer Engineering, Prentice Hall, Englewood Cliffs New
Jersey, 1993
[18] Strassberg D, Home-automation buses: protocols really hit home, EDN article,
April 13, 1995, v40 n8 pp.69-79.
[19] Truong, Tony; The Internet Power Line Adapter, [Thesis], Dept. of Computer
Science and Electrical Engineering, University of Queensland, October, 1999
- 62 -

Home Automation, Power Lines and the Internet Quenten Alick
[20] Wacks K, The Impact of Home Automation On Power Electronics, Proceedings
of International Conference on Consumer Electronics, June 7, 1996.
[21] Wright M, Home-automation networks mature while the PC industry chases a
new home LAN, EDN article, June 4, 1998, v43 n12 pp.101-1012.
- 63 -