A-Team
Home Central Control Unit
Kevin Cooke
Peter Larson
Ben Verstegen
Andreas Rugloski
Aden Abdillahi
Our Design
Home Central Control Unit
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–
Controllable by
 Laptop
 Phone
Able to adjust or turn on/off household items
Functional Requirements
User will be able to access the system via:

Laptop: Through serial port (possibly wirelessly
from within the house)
 Phone: User ID, Password, Voice prompt,
Device status (with option to change device
status)
Possible Extensions

Lights dim

Wireless laptop control

Remote made specifically for our system

LCD screen on the system

System can give feedback to user
Physical Characteristics

About the size of a bread box

Plugs into 120V outlet

Hidden

Plain
Phone Interface R-TT7

Upon dialing you will hear a voice prompt
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Enter user ID and password
Toggle/Check device status

Touch Tone phones (including cell phones)

R-TT7 connects to phone line
Decodes DTMF touch tones
DMTF Touch Tones


Dual-tone multi-frequency
Dialed 1
= 1209Hz & 697Hz

Dialed 8
= 1336Hz & 852Hz
Serial Interface



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Computer connects to home unit via DB9 cable
Control of each device using keyboard
Monitor shows status of each device
M68HC11K1 Serial Peripheral Interface (SPI)
Up to seven bi-directional I/O ports
Control Functions

Ability to check and adjust settings such as a
thermostat
Control function to set temperature

Control different infrared devices (TV,stereo)
Sending different IR pulses to devices
Block Diagram Outline
Control Unit Block Diagram
Device Block Diagrams
Hardware VS. Software
Hardware
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–
–
Lack of programming experience, so we
will stick to hardware when possible
Touch-Tone Decoder
Thermostat and Garage Door Devices
Software
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–
–
Microcontroller
Infrared Signal Processing
I/O Signal Processing
Purchasing VS. Building

Readily available products that we can use

Purchasing saves time, but building usually
saves money

Money vs. Time … which is our biggest factor?

Saved time allows for greater functionality of the
system (more things controlled)
The Breakdown
Microcontroller Unit
We must learn all of the relevant abilities of the
68HC11 microcontroller. This will be a lot of the
“brains” of our unit.
Phone Signal
We will need to find hardware that can convert a phone
signal into usable data that we can have perform
functions.
More Parts…
Infrared Devices
We will need to learn how infrared signals are sent to
electronics. Once we learn how it is done, we must be
able to manipulate or reproduce this in order to control
devices using our system.
Thermostat/Garage Door Circuits
We need to buy, take apart, and understand these
circuits so we will be able to control them.
Why These Parts

R-TT7 Touch Tone Decoder: This piece of
hardware does the exact function we were looking for
and is relatively inexpensive.

68HC11 K1 Microcontroller: Readily available.
Provided for us. Memory mapped I/O. Good serial
communications interface.

Honeywell Pro Thermostat: Basic, so easier to
learn the circuit. Displays the actual temperature and
the set temperature, so it will display the changes the
user makes.
What We Will Buy
1)
2)
3)
4)
5)
6)
Thermostat
Garage Door Opener
Hardware that converts phone input into usable
signals
Blue tooth module transceiver for laptop*
LCD screen*
IR Transmitter*
*indicates that we may not need the item
Costs







Garage Door Motor –
Thermostat –
Basic LCD screen –
Blue Tooth Wireless Transceiver –
Touchtone Decoder (TT-7) –
I/R Transmitter –
Misc (Resistors, Caps, printed circuit board)
$75.00
$47.95
$ 3.95
$59.00
$41.95
$15.00
$50.00
Total Cost: $292.85
Timeline
Deadlines and Goals


Feb 27th – CDR: phone control over lights
Mar 20th – Milestone I: computer and phone
control over lights and at least 1 infrared device

Apr 17th – Milestone II: computer and phone
control over lights, infrared device, thermostat and
garage door motor

May 3rd – Capstone Expo: wireless computer and
phone control over lights, thermostat, infrared devices,
all bugs worked out
Risk and Contingency Plan
Largest Risks:
-
Lack of programming experience (all EE’s)
No one in the group has infrared experience
Time constraints
One semester
 Learning curve

-
Using unfamiliar hardware
Fallback Options

Project design is very modular

Test with wire wrap rather than going straight to printed
circuit board

Get help from experienced programmers or people
who have used the troublesome hardware

Exchange a non-functioning device with an alternate
system device
Group Member Skills



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Kevin – Programming experience, hardware
Peter – Hardware, soldering
Aden – Programming experience
Andreas – Hardware, technical writing, soldering
Ben – Programming experience
Who Needs to Learn What




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Kevin – Serial port interface (I/O)
Peter – Printed circuit board
Aden – Serial port interface (I/O)
Andreas – Thermostat/garage door circuits
Ben – Infrared signals
THANKS!
ANY QUESTIONS?