EVADE: Emergency Vehicle Alert DEvice

EVADE: Emergency Vehicle Alert DEvice
Group D, Fall 2010
Stephen Watson, Charles Logan, Joshua Guinn, Derrick Nelson
EVADE:
Emergency Vehicle Alert DEvice
EVADE: Emergency Vehicle Alert Device
Project Origination:
Have you ever:
– Heard the sirens, but not known where they were coming
from?
– Been taken by surprise by an emergency vehicle and not
had time to get out of the way?
– Not seen the lights or heard the siren until they are right
behind you?
Then you understand the need for a more advanced
warning system that can save time and lives.
EVADE: Emergency Vehicle Alert Device
Motivation:
The group was struck by the fact that more and more
frequently emergency vehicles are not seen or are simply
ignored by drivers on the road. This could be caused by
better insulation that makes cars quieter, larger vehicles on
the road creating a visual obstruction, or by increased
distractions on the road like cell phones and loud music. In
order to overcome these obstacles, an advanced alert
system is needed that does not rely on line-of-sight or sirens
and has the capability of capturing the driver’s attention.
EVADE: Emergency Vehicle Alert Device
Goals:
The objective of the emergency vehicle alert device is
to surpass the current obstacles for alerting drivers by
transmitting a signal from the emergency vehicle that will be
picked up by cars. This signal will trigger a visual alert to
inform the driver what type of vehicle is approaching and from
what direction. Simultaneously, the signal will quiet the
interior of the car and play an audible alert message in both
English and Spanish.
EVADE: Emergency Vehicle Alert Device
Basic Objectives:
EAT - Emergency Alert Transmitter:
• Transmission begins simultaneously with lights and sirens
• Sends GPS and compass headings to determine approach direction.
• Transmission radius is large enough to provide the desired advanced
alert.
• Does not inhibit normal vehicle operation or require extra work from
driver.
• Does not put unusual strain on other vehicle components or battery.
EVADE: Emergency Vehicle Alert Device
Emergency Alert Transmitter Block Diagram:
HEC
8-BIT
CONNECT TO EXISTING
SWITCH THAT TURNS ON
EMERGENCY LIGHTS.
1
3
J
COMPASS SIGNAL
POWER
POWER
IGNITION
TOD
TCU
8-BIT SIGNAL
3
D
J
8-BIT SIGNAL
1
MEMORY POWER
(IF REQ'D)
_
+
_
PCM
3
ETD
D
3
EMERGENCY VEHICLE
BATTERY
1
(POWER SUPPLY)
J
8-BIT SIGNAL
+
AUTOMOBILE
ANTENNA
1
3
J
1
EVADE: Emergency Vehicle Alert Device
Basic Objectives:
EAR - Emergency Alert Receiver:
• Automatically detects signal and alerts driver during normal
operation.
• Allows normal operation of vehicle when signal not detected
• Shuts down stereo and plays audible alert message until vehicle is
out of range, then resumes normal operation.
• Displays direction of approach to driver on a physical display
screen.
• Uses low power that will not affect other systems in the car or
strain battery supply levels.
EVADE: Emergency Vehicle Alert Device
Emergency Alert Receiver Block Diagram:
EVADE: Emergency Vehicle Alert Device
Project Management Flowchart:
Write Complete
Project Document
Beginning
Beginning of
of Senior
Senior
Design
I
Design I
Develop
Develop
Functional
Functional
Requirements
Requirements &
&
Block
Diagram
Block Diagram
Research
Research
Possible
Possible
Implementations
Implementations
Joshua:
Joshua:
Hall
Hall Effect
Effect Compass
Compass
GPS
GPS Sensor
Sensor
Transmitter
Transmitter &
& Receiver
Receiver
Derrick:
Derrick:
Audio
Audio Bypass
Bypass Unit
Unit
Power
Power Control
Control Unit
Unit
Legal
Restrictions
Legal Restrictions
Chuck:
Chuck:
Recorded
Recorded Messages
Messages
Visual
Visual Display
Display
PCB
PCB Diagrams
Diagrams
Proposed
Proposed Design
Design
Created
Created with
with
Schematics
Schematics
Build
Build prototype
prototype
Not
Working
Test
Test Prototype
Prototype for
for
Correct
Correct
Functionality
Functionality
Properly Functioning
Stephen:
Stephen:
Transmitter
Transmitter Control
Control Unit
Unit
Receiver
Receiver Control
Control Unit
Unit
Programming
Programming
Present
Present Final
Final Design
Design &
&
Complete
Senior
Design
Complete Senior Design IIII
Subsystem #4 - Derrick Nelson
TOD – Turn-On Device
PCM – Power Control Module
RAA – Recorded Audible Alert
SBU – Switching Bypass Unit
EVADE: Emergency Vehicle Alert Device
Turn-On Device:
•Controls power flow to components to reduce waste heat
•TOD(EAT) – simple switch connected to emergency lights,
interfaces with transmitter
•TOD(EAR) – software implementation in RCU, interfaces with RAA
Emergency Alert
Transmitter
Emergency Alert
Receiver
EVADE: Emergency Vehicle Alert Device
PCM Design Objectives:
•Operate on standard 12V vehicle power
•Provide multiple voltage levels for various components
•Provide clean source of power for transmitter and receiver:
must not introduce radio frequency interference (RFI)
•Both PCMs operate whenever vehicle is running, TOD
responsible for limiting power consumption
•Design Decision – linear vs. switching regulators
• Cost, efficiency/heat, noise
EVADE: Emergency Vehicle Alert Device
Power Specifications:
EAT (Transmitter)
EAR (Receiver)
Item
Voltage
(V)
Current
Line
(mA)
PIC
1.8 – 3.6
250
3.3
Transmitter
1.8 – 3.6
12.5
3.3
GPS
3.3
50
3.3
HEC
8 – 13
10
3.3
Total
Current
(mA)
322.5
Item
Voltage
(V)
Current
(mA)
Line
GPS
3.3
50
3.3
HEC
8 – 13
10
3.3
PIC
1.8 – 3.6
250
3.3
RAA
2.5 - 5.5
20
3.3
Receiver
4.8 – 5.5
3
5
5
28
5
2.7 – 5.5
2
5
5
400
5
SBU
VDU controller
VDU display
Total
Current
(mA)
330
433
EVADE: Emergency Vehicle Alert Device
Voltage Regulators:
•3 regulators used to achieve the required
voltage levels
• All Low Drop-Out voltage for
efficiency
• Very clean output voltages
LD2908050 (5.0 V, 800 mA,
STMicro.)
TPS79633 (3.3 V, 1A, TI)
TC1107 (3.3 V, 300 mA,
Microchip)
•Vin: 12V, filtered
•Vout: 3.3 and 5V; filtered
•Current Limits: Well above spec.
EVADE: Emergency Vehicle Alert Device
SBU Design Objectives:
•Cause no distortion of stereo signal when EVADE not in use
•Completely and cleanly bypass stereo signal when in use
•Must operate whether the stereo system is in use or if it is off
EVADE: Emergency Vehicle Alert Device
Signal Bypass:
•Bypass accomplished w/ electromechanical relays ( 1 per
speaker)
• TX2-5 (Panasonic)
• 4 ms switching speed
• Max Ratings: 60 W, 2 A
•Simple interface with the vehicle’s speaker wires
EVADE: Emergency Vehicle Alert Device
Recorded Audible Alert (RAA):
The RAA alerts the driver to the presence of an
emergency vehicle by playing an audio message through the
vehicle’s speakers.
RAA Design Objectives:
•Generate alert messages in English and Spanish
• Pre-recorded, or
• Speech synthesizer
•Determine correct message to be played
•Send message to SBU and trigger bypass
EVADE: Emergency Vehicle Alert Device
Recorded Audible Alert:
•Nuvoton ISD1760 ChipCorder
• Voice record and playback, storage on
internal Flash memory
• Stand-alone and SPI modes
• No need for external audio amplifier
•Atmel Atmega328
•
•
•
•
Low-power 8-bit microcontroller
32KB Programmable Flash
SPI interface with ISD1760
Programmed on Arduino Uno
development board
EVADE: Emergency Vehicle Alert Device
RAA Operation:
Subsystem #2 - Joshua Guinn
HEC/GPS – Hall Effect Compass & GPS
ETD – Emergency Transmission Device
EVADE: Emergency Vehicle Alert Device
HMC 6352 Electronic Compass
Supply Voltage = 2.7 to 5.2 V
Heading Accuracy = 2.5 deg
Operating Temp = -20 to 70ºC
Size = 6.5 x 6.5 x 1.5 mm
Weight = 0.14 grams
I2C Serial Interface
EVADE: Emergency Vehicle Alert Device
The heading, output data, will be a value in tenths of degrees from
zero to 359.9, N = 0, and provided in binary format over two bytes.
These two bits will then give our eight cardinal directions.
N
> 337.5 OR <= 22.5
NE
> 22.5 AND <= 67.5
E
> 67.5 AND <= 112.5
SE
> 112.5 AND <= 157.5
S
> 157.5 AND <= 202.5
SW
> 202.5 AND <= 247.5
W
> 247.5 AND <= 292.5
NW
> 292.5 AND <= 337.5
EVADE: Emergency Vehicle Alert Device
GPS Modules researched
General
Characteristics
GlobalSAT
EM-408
Modulstek
MG-S01SP
Antenova
M10214-A1
Receiver
Architecture
20 channels
1 satellite / channel
L1 1575.42 MHz
1.023 MHz chip rate
20 channels
1 satellite / channel
L1 1575.42 MHz
1.023 MHz chip rate
20 channels
1 satellite / channel
L1 1575.42 MHz
1.023 MHz chip rate
Antenna
Built-in or
External
Built-in
Built-in
Data Output
Protocol
SiRF Binary
NMEA 0183
NMEA 0183
SiRF Binary
NMEA 0183
Dimensions
36.4 x 35.4 x 8.3mm
with antenna
19.0 x 19.0 x 6.5mm
antenna
18 x 18 x 2mm
43 x 9 x 4mm
with antenna
EVADE: Emergency Vehicle Alert Device
GlobalSAT Tecnology Corporation EM-408
EVADE: Emergency Vehicle Alert Device
GPS Output Protocol NMEA 0183
•NMEA “National Marine Electronics Association”
•The NMEA 0183 standard uses a simple ASCII, serial communication
protocol.
•Data is transmitted at 4800 baud rate through UART.
•Data is transmitted in sentences.
•GGA ($GPGGA) GPS Position, Time And Fix.
$GPGGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh
EVADE: Emergency Vehicle Alert Device
Performance Characteristics
•Maximum altitude
18,000 m
•Maximum velocity
545 m/s
•Maximum acceleration
4g
•Position accuracy
2.5 m
•Acquisition rate
< 35 sec cold start
< 1 sec hot start
EVADE: Emergency Vehicle Alert Device
Power and Environmental Specifications
•Power supply
3.3 to 5.5 V DC
•Main supply current
Acquiring 50 mA
Tracking 30 mA
•Operating temperature
-20 to 85ºC
•Storage temperature
-40 to 85 ºC
•Relative humidity
5 to 95 %
EVADE: Emergency Vehicle Alert Device
Transmitters Researched
•MICRF 113
•TXM-433-LR-S
•PD 5000
EVADE: Emergency Vehicle Alert Device
Operating Ratings
•Supply voltage
2.1 to 3.6 V
•Output power
-4 to 4 dBm
•Operating temperature
-40 to 85 ºC
•Transmitter frequency
433 MHz
•Data rate
10 kbps
EVADE: Emergency Vehicle Alert Device
TXM-433-LR-S Operating diagram
Pin Name
GND
Data
GND
LADJ/VCC
PDN
VCC
GND
ANT
Pin Description
Ground
Data input
Ground
Output power level adjust
Power down
Supply voltage
Ground
50 ohm RF output
EVADE: Emergency Vehicle Alert Device
Recievers researched
•MICRF002YM
•RMX-433-LR-S
•PD 5000
EVADE: Emergency Vehicle Alert Device
Operating Ratings
•Supply voltage
2.7 to 3.6 V
•Receiver sensitivity
-112 dBm
•Operating temperature
-40 to 70 ºC
•Receiver frequency
433 MHz
EVADE: Emergency Vehicle Alert Device
RXM-433-LR-S Operating diagram
Pin
Number
Pin Name
4
GND
Ground
5
VCC
Pin Description
6
PDN
7
RSSI
Supply voltage
Power down
Received signal strength indicator
8
DATA
Data Output (Digital Output)
15
GND
16
ANT
Ground
50 ohm RF output
Subsystem #3 - Stephen Watson
TCU – Transmitter Control Unit
RCU – Receiver Control Unit
EVADE: Emergency Vehicle Alert Device
Function of the Transmitter Control Unit:
The transmitter control unit is essentially the brains
behind the entire transmitter. It serves as the central hub that
collects the information from the GPS and Hall effect
compass and condenses the positional information as well as
the vehicle type into a single signal which is broadcast to the
receiver. The transmitter control unit is also required to
create the time delays between transmissions so that signals
do not overlap.
EVADE: Emergency Vehicle Alert Device
Block Diagram of Transmitter Control Unit:
GPS
UART
PIC
Controller
Compass
3 Bits
Transmitted
Signal
To Transmitter
for Modulation
EVADE: Emergency Vehicle Alert Device
Controller Selection:
Research narrowed the choice of controller to a FPGA or PIC
microcontrollers.
With limited testing, PIC controllers were
selected as the controller of choice.
Reasons for Choosing PIC:
• Simplified programming in C
• Very inexpensive (free samples)
• Easy to use serial protocol
• Numerous guides and sample
code to assist with programming
and debugging
EVADE: Emergency Vehicle Alert Device
Programming Flowchart:
Unit is
turned on
Switch
Flipped On?
Yes
No
Run Loop For
Delay Between
Transmissions
Read GPS
Position to
Memory
Combine Latitude,
Longitude,
Compass Bits
Into Single Signal
Output Signal to
Transmitter for
Modulation
EVADE: Emergency Vehicle Alert Device
Transmission Delay:
• For a speed of 45 mph:
45 mph => 66 ft/sec
• For a one second delay:
66 ft/sec x 1 sec = 66 ft
• With the allowable test range by the FCC, this is the best
delay period between transmissions.
EVADE: Emergency Vehicle Alert Device
Transmitted Data Format:
Security Code
Compass
Latitude
Longitude
5 Bytes
2 Bytes
8 Bytes
9 Bytes
• The total number of bytes to transmit is well below the limit
of the transmitter and receiver.
EVADE: Emergency Vehicle Alert Device
Function of the Receiver Control Unit:
The receiver control unit is the most fundamental
processing unit of the entire project. As the central control
unit, it is required to receive the demodulated transmission
signal and properly extract the information. After storing this
information, the receiver control unit must compare the
positional information of the emergency vehicle with its own
GPS coordinates and compass heading to determine if the
vehicle paths will intersect and from what direction the
emergency vehicle is approaching. The receiver control unit
must then initiate the visual and audible alert systems.
EVADE: Emergency Vehicle Alert Device
Block Diagram of Receiver Control Unit:
GPS
Compass
UART
3 Bits
Antenna & Transmitted
Signal
Demodulator
5 Bit
Alert Code
Recorded
Audible
Alert
5 Bit
Alert Code
Visual
Display
Unit
PIC
Controller
EVADE: Emergency Vehicle Alert Device
Directional Calculations:
In order to calculate the direction of the car relative to the
emergency vehicle, the latitude (x value) and longitude (y value)
for the emergency vehicle are subtracted from the latitude and
longitude of the car.
Based on the whether the
coordinates are +/-, the compass
direction is used to determine if the
vehicles will intersect. This is also
used to determine the direction the
emergency vehicle is approaching
relative to the car.
Subsystem #4 - Charles Logan
VDU – Visual Display Unit
PCB Design
EVADE: Emergency Vehicle Alert Device
VDU
Visual Display Unit (VDU)
• 16x4 dot matrix LCD
• Display heading under
normal operation
• Small size – mountable
in dash.
EVADE: Emergency Vehicle Alert Device
LCD Schematic
RCU
Hitachi
HD44780
LED
R
PIN 2
•The LCD Display will
be driven by the Hitachi
HD44780
LED
8/1
R
LED
14/8
R
LED
5V
•Signal for the LED’s
obtained from the RCU
R
LED
R
LED
R
LED
PIN 1
R
LED
R
EVADE: Emergency Vehicle Alert Device
LCD2
PCM
RCU
PIC
Hitachi
HD44780
RS
R/W
E
DB0-DB7
Segment
Driver
SEG
1-40
COM 1-16
COM 17-32
SEG
41-80
Segment
Driver
SEG
80-160
EVADE: Emergency Vehicle Alert Device
VDU-LED
Visual Display Unit (VDU)
Under emergency
conditions, an
LED will blink to
alert the motorist
of the direction
the emergency
vehicle is
approaching
EVADE: Emergency Vehicle Alert Device
VDU-LED
Printed Circuit Board (PCB) Design
• Created using PCB Artist software for creating the fab, pcb,
and dxf files necessary to create a printed circuit board.
• Created by Advanced Circuits (4pcb.com)
EVADE: Emergency Vehicle Alert Device
VDU-LED
Sample PCB Diagrams from RAA
.pcb File Design
Schematic Design
EVADE: Emergency Vehicle Alert Device
VDU-LED
Final Prototypes:
Emergency Alert
Transmitter
Emergency Alert
Receiver
EVADE: Emergency Vehicle Alert Device
VDU-LED
Testing:
•
•
•
•
•
MPLAB Simulations
Serial tracing
Distance testing
Lots of breadboards
Even running wire
down 4 floors &
half-way round
Engineering 1
EVADE: Emergency Vehicle Alert Device
Budget:
Module
Quantity
Expected Cost
Actual Cost
Antenna
2
$20
$20
Car Stereo & Speakers
1
Donated
Donated
Transmitter
1
$30
$60
Compass & GPS
2
$40
$165
Power Supply
2
$50
$30
Recorded Audio Chips
1
Sampled
$30
Microcontollers
2
$180
$60
PCB
1
$100
$180
Display Screen and LEDs
1
$30
$80
$100
$100
Incidentals
Expected Total Cost:
$530
Total Expected Cost ( 2X Buffer)
$1060
Actual Cost
$705+
EVADE: Emergency Vehicle Alert Device
Milestones:
Tasks
Choose Project
Develop Specs
Research
Documentation
Order Parts
Test Subsystems
First Prototype
Mid-term Demo
Scenario Testing
Final Prototype
Present Project
GRADUATE!
Jan.
Feb.
Mar
April
May
June
July
Aug
Sept
Oct
Nov
Dec
EVADE: Emergency Vehicle Alert Device
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