Transcript ECO-SEC Home Security System

Group 18
Lucas Chokanis
Daniel Ramirez
Lloyd Harrison
Philip Teten




A Proposal from Researchers to Implement
Their Algorithms
Design a Power Efficient Thermostat to
Control a Vehicle’s Heating, Ventilation, and
Air Conditioning (HVAC) Systems
Create a Control System That will Significantly
Extend the Life-Cycle of a Vehicle’s Battery
Provide a Control System that is Feasible to
adapt for Future Additions

Ability to Detect Input:
◦ Temperature of the Vehicles Interior
◦ Temperature of the Evaporator
◦ Extra Temperature Sensor for Researchers Use

Control Output:
◦
◦
◦
◦

Speed of the blower motor (High, Med, & Low)
Speed command of the PMSM motor.
Condenser Fan
Clutch Control?
Implement a User Interface
◦ LCD Screen and LED’s for Feedback
◦ Push Buttons for User Control

Electrically Noisy Environment:
◦ Use of Parts that Meet Automotive Requirements

15 ft Transmission Lines:
◦ PMSM Motor Control
◦ Remote Temperature Sensors

Highly Intuitive Programming:
◦ Giving Researchers Ease of Understanding

Voltage Recieved:
◦ 12 VDC to 15 VDC

Output to Motors:
◦ 12 VDC Three Speed with Separate Hi, Med, Low
input
◦ 12 VDC On/OFF 12VDC motor.
◦ Linear 0-3.3V “ramp” speed command

Relays:
◦ Coil Voltage of 12 VDC

Microcontroller
◦ MSP430
◦ C2000
Parametrics
Architecture
Flash (KB)
Frequency (MHZ)
RAM (KB)
GPIO
I2C
UART
SPI/SSI
ADC
Rating
MSP430F2274-Q1 TMS320F28030
16-bit
32
16
1
32
1
1
1
10-Bit/12 channels
Automotive
32-bit
32
60
12
44
1
1
2
12-bit/16 channels
Standard
LM4F110B2QR
32-bit
32
80
12
43
4
8
4
12-bit/12 channels
Standard
The chosen microcontroller is the
MSP430F2274-Q1 for the following reasons:
 Ultra-Low power
 Code Composer Studio IDE
 Qualified for Automotive applications
 Sponsor provided the MSP430 Target board
and USB programmer
 Temperature sensor

Ambient temperature Sensor:

Evaporator temperature Sensor:

Auxiliary Temperature Sensor:
◦ Housed on main thermostat circuit board.
◦ Provides feedback to the user via LCD screen
◦ Remote sensor location.
◦ 15ft away from main board as required by the customer. Its
purpose is to keep track of the rate at which the evaporator is
cooling.
◦ Prevents the evaporator from freezing over.
◦ Feeds data back to the MCU to be that will be used to improve
efficiency.
◦ Remote sensor location (<15ft away from main board).
◦ Feeds data back the MCU to be used to improve efficiency.
Model
Manufacturer
Accuracy
LM35A
±0.2ºC
ADT7420
Texas
Instruments
Texas
Instruments
Analog Devices
ADT7320
Analog Devices
±0.2ºC
TMP100
Texas
Instruments
±3ºC
LM35CA
±0.2ºC
±0.2ºC
Temp.
Range
-40ºC to
110ºC
-40ºC to
110ºC
-40ºC to
125ºC
-40ºC to
125ºC
-55ºC to
125ºC
Current
Draw
60µA
60µA
265µA
265µA
45µA
Output
Price $
Linear
Voltage
Linear
Voltage
16-Bit
5.60
16-Bit
SPI
4.87
14.61
4.87
2.15
The chosen temperature sensors were the
ADT7320 for the following reasons:
 Very high accuracy rating on a wide
temperature scale.
 We can expect reliable temperature readings
in a cold environment such as the evaporator.
 User programmable with multiple features
 Temperature resolution up to 16-bits.

Extending The SPI Bus for Long Distance
Communication:
◦ For the remote sensors, it is possible that propagation
delay could be significant enough to hinder data
transmission.
◦ Once we attempt to conduct SPI communications at
distances greater than 15 feet, we will know if
propagation delay will require a hardware solution.
◦ If this turns out to be the case, dual differential
transceivers will be used to refresh the clock signal
protect the data transfer from noise.
◦ If the signal is fed back to the master from the slave,
data transmissions between the master and slave will
occur at the same delayed clock signal.
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4 Digits 1 Decimal Accuracy
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Driver Uses Less Pin Outs
Good for Intuitive Programming
D1
0
0
D2
0
0
D3
0
0
D4
0
1
0
0
1
0
0
1
0
0
1
0
0
0
1
1
1
1
Function
No Change
Store Data in Latch 4 to be
Digit 4
Store Data in Latch 3 to be
Digit 3
Store Data in Latch 2 to be
Digit 2
Store Data in Latch 1 to be
Digit 1
Store Data in All Data Latches,
Displayed in
Displayed in
Displayed in
Displayed in
Display All
B3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
B2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
B1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
B0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
LCD Display
0
1
2
3
4
5
6
7
8
9
A
b
C
d
E
F
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4 Digits 1 Decimal Accuracy
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View Changing: Scroll Through
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Temperature Set for Nominal Setting
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Setting the Blower Motor State
Analog Out
0.165V to 2.135
10 Settings
PWM Input
Lowpass Filter
Eliminates High Frequency Components
Maintains Analog DC Value
w0 = 1/RC = 1kHz
Dual Differential Driver
To Drive the 15’ of Cable
Better Noise Immunity
DO+1=DI1/2
DO-1 = -DI1/2
Shielded Twisted Pair
Higher Noise Immunity
Noise Cancels
Dual Differential Reciever
R2OUT2 = (RIN2+) – (RIN2-)
Analog Out
0.165V to 2.135
10 Settings
Solid-State Relays (SSRs) Vs. Electromechanical
Relays:
Relay Type
Solid-state
Pros

Faster switching times

Increased lifetime (no
moving parts)

Bounceless switching

No sparking or arcing

Silent operation
Electromechanical



Lower ON resistance
(ohmic contacts)
Higher OFF resistance
(no current flow)
Fails “open”
Cons

Higher ON resistance
(more power
dissipated)

Small OFF resistance
(small reverse leakage
current)

Fails “short”

Noisy

Shorter lifetime (10^5
to 10^7 switching
cycles)

Switch bouncing

Arcing across contacts
Motor Control: Choosing Relay Current Rating
DC Supply
Voltage (V)
12.0
12.5
13.0
13.5
14.0
14.5
15.0
LO-speed
Current (A)
5.7
5.9
6.2
6.4
6.6
6.8
7.1
MED-speed
Current (A)
8.6
8.9
9.0
9.3
9.5
9.8
9.9
HI-speed
Current (A)
15.0
15.6
16.1
16.9
17.4
18.0
18.7
Blower motor current draw (low, medium, and high speeds)
Note: Highlighted values are interpolated values due to limitations in
test equipment.
Motor Control: Choosing Relay Current Rating
DC Supply
Voltage (V)
12.0
12.5
13.0
13.5
14.0
14.5
15.0
Motor
Current (A)
7.0
7.5
7.9
8.2
8.7
9.1
9.4
Condenser Fan Motor Current Draw
Note: Highlighted values are interpolated values due to limitations in
test equipment.
P/S section:
Items Drawing
Current
Total per section:
Design current
limit:
P/S efficiency:
3.3V
6.5 mA – MCU
795 uA –
Temperature
sensors
(3 x 265uA)
10.8 mA
10 mA
5V
50 uA – LCD driver
91 %
84 %
Current Draw
50 uA
1 mA
3.3V P/S EFFICIENCY
5V P/S EFFICIENCY
Load
Supply
Voltage (V)
Supply
Current (mA)
3.3V Output
Current (mA)
5V Output
Current (mA)
Efficiency (%)
Minimum
12
13
11.3
9.77
55.2
15
12
11.3
9.83
48.0
12
11
12.2
6.39
54.7
15
10
12.2
6.39
48.1
12
12
12.8
6.81
53.0
15
11
12.8
6.81
46.2
Medium
Maximum
Item
Price
Microcontroller - MSP430F2274-Q1
Free Sample
Temperature Sensors - ADT7320
$
4.87
3 No $
14.61
PCB by 4PCB.com
$
33.00
1 No $
33.00
LCD Display - Lumex LCD-S401C39TF
Free Sample
1 Yes
-
LED for User Interface
Owned
8 Yes
-
Push Buttons for User Interface
$
Dual Differential Driver - DS90LV027AQMA
Free Sample
2 Yes
-
Dual Differential Receiver - DS90LV028AQMA
Free Sample
2 Yes
-
Shielded Twisted Pair - C1352-100-ND
$
1 Yes $
NPN transistor 200mA ICmax, 40V Vce(breakdown), through hole
Switching Regulator - TI LM26003
Quantitiy Paid Total
1 Yes
0.19
66.96
$0.17
Free Sample
-
5 No $
10 Yes $
3 Yes
0.95
66.96
1.74
-
Relay automotive SPST 12V, 15A
$1.79
6 Yes $
10.74
Relay automotive SPST 12V, 30A
$5.02
2 Yes $
10.04
Capacitors
$2.50
Diode, Schottky 40V 30mA, through hole
$0.66
5 Yes $
3.30
Inductor 1mH, 10% through hole
$2.79
3 Yes $
8.37
Resistors
$0.72
77 Yes $
6.79
TSSOP-20 to DIP-20 SMT Adapter (for TI LM26003 chip)
$4.49
2 Yes $
8.98
TOTAL
65
$
17.47
$ 182.95
Parts Ordered
Testing
Coding
Fabrication
Design
Research
0%
20%
40%
60%
80%
100%

Noise from motors induced into MCU
◦ Possible Solutions: Filters, bypass capacitors,
optocouplers

Multiple Temperature Sensors Sharing One
SPI Interface.