Transcript UNATTENDED COOKING ALARM SYSTEM

UNATTENDED COOKING
ALARM SYSTEM
PREPARED BY: Chepchumba Soti Limo
MENTORED BY: Dr. Stanislaw Legowski
DEPARTMENT: Electrical and Computer Engineering
CLASS: Senior Design II, Spring 2011
BACKGROUND
Statistics according to the U.S Fire Administration
on residential fires:
 356,200 fires
 2,480 deaths
 12,600 injuries
 ≈7.250 billion dollars in losses
Possible causes of fires in residential areas:
 Cooking
 Heating
 Electrical malfunctions
THE REAL PICTURE
WHAT’S BEEN DONE ABOUT THIS ISSUE?



Smoke detectors (CO2 and CO)
Inbuilt timers in cookers
Heat detectors
Common feature: Alert user
IDEAL SYSTEM
Tell when something is on the cooktop
 Intelligence to tell if children are around
 Alert user when cooker has been on for too long
 More visible lights
 Sense a spill
 Alert user if they have not been paying attention
(if desired)
 Sense smoke
 e.t.c.

OBJECTIVES
Objective: to develop a working model of an after
market safety device that will interface the wall
outlet and cooker plug that will have the following
features:
1. Determine when the cooker is on
2. Determine if there is someone in the kitchen and
if so, how far are they from the cooker
3. Sense when there is smoke in the kitchen
Based on the above conditions, the system will be
able to take action accordingly to reduce the risk of
a potential fire
DESIGNING
Two main parts
1. Hardware
2. Software
HARDWARE DESIGN
OVEN PROTOTYPE
OVEN PROTOTYPE
CURRENT SENSING SUBSYSTEM
Purpose:
 Be able to tell when load is connected to system
 Know exactly when system is on
Part:
 ACS712ELC-05
Features:
 Output proportional to input (AC/DC)
 Stable output offset voltage
 Rated for 5A
 5V operating voltage
CURRENT SENSING SUBSYSTEM
MOTION SENSING SUBSYSTEM
Purpose:
 Monitor motion around cooking area
Part:
 AMN24111
Features:
 High performance infrared human motion
 Detection range: Horizontal - 110º
Vertical - 93º
 Excellent noise resistance (radiation power supply)
 Analog output
 5V operating voltage
MOTION SENSING SUBSYSTEM
PROXIMITY SENSING SUBSYSTEM
Purpose:
 Monitor how far motion is from cooktop
Part:
 GP2Y0A21YK0F
Features:
 Combination of infrared and position sensing
detection signal processing circuits
 Range: 10 – 80cm
 Analog output
 5V operating voltage
SMOKE DETECTING SUBSYSTEM
Purpose:
 Monitor smoke conditions
Part:
 A5303
Features:
 Photoelectric chamber
 Chamber sensitivity test
 Built in circuit to reduce false triggering
 Digital filter on I/O for noise immunity
 Test chamber conditions
 Logic outputs
 2.3 – 5V operating voltage
SMOKE DETECTING SUBSYSTEM
USER INTERFACE SUBSYSTEM
Purpose:
 Obtain operating instructions from user
 Display current state of system
 Alert user of causes of alarms and system
shutdown
Parts:
MICROPROCESSOR UNIT
Purpose:
 “Brain” of system
Part:
 ATMEGA644P
Features:
 10 bit AD
 2.7 – 5.5V Operating voltage
ENTIRE CIRCUIT DIAGRAM
SSR2
IMain
I1
I2
4.6uF
Capacit
ACDC
P1
P2
P3
P4
P5
P6
P7
10k
P14
P13
P12
P11
P10
P9
P8
10k
2.2uF
10k
Current
0.1uF
SSR1
Male1
Female1
Male2
Female2
Inverte
P1
P2
P3
P4
P5
P6
P7
P14
P13
P12
P11
P10
P9
P8
C11
1uF
10k
Compart
P1
P2
P3
P4
560
1k
5V
G
1uF
1uF
AD790
10k 40%
Power
P8
P7
P6
P5
LCD
510
1M
1uF
1uF
AlertLE
1k
Buzzer
P8
P7
P6
P5
R22
39k
P1
P2
P3
P4
Prox
1uF
ProxMot
MPU
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
10k
560
P40
P39
P38
P37
P36
P35
P34
P33
P32
P31
P30
P29
P28
P27
P26
P25
P24
P23
P22
P21
Motion
Smoke1
Switch
15k
Smoke2
10
90
SmidtTr
P8
P9
P10
P11
P12
P13
P14
Keypad
P7
P6
P5
P4
P3
P2
P1
OnOffLE
.1uF
.1uF
.1uF
4.7k
4.7k
4.7k
470k
470k
470k
SOFTWARE DESIGN
RESULTS

Met design requirements
The design is as good as the testing goes…
 Limited testing time
 Reduce hardware by debouncing keypad switches
only in software
 Compress system design to fit industry standards
 Use “cop watchdog” timer on mpu to avoid logic from
“hanging” in a loop
 Use standby feature in mpu to reduce power
consumption
 Use more defensive programming to account for
potential noise issues
CONCLUSION
Who can use this system?
ANYBODY!
Interesting facts on things to come:
 National building code – install sprinklers
Disadvantages of sprinklers
 Bath houses and cause damage
 Extra maintenance costs
 Inevitably fail
 Cost per square ft. $1.61 (x 2135)

May not be the answer but definitely an option
worth considering.
QUESTIONS?
Thank you!